So I have come to the conclusion my D6D has a cooling problem. It is not a dire cooling problem but it renders the machine unusable for longer periods in summer. The problem is I am pretty sure not in the transmission as it never gets any further then 3/4 of the way through the green, even when the engine reaches the red. The engine will not start running hot until the torque converter gets at least 1/3rd into the green which takes an hour or more. Then if I load the engine up, the temperature it will slowly creep up to the red. It has done this ever since I bought it a couple of years ago. If I look at the machine I can see the following has been replaced. Transmission water cooler and the transmission radiator cooler, the fan belts are tight and the pulleys are new. The water pump also lacks paint so I suspect it also is new. I pulled the thermostat and checked it and it is fine. The only thing not checked in the engine timing, which I have heard can cause heating issues. Which leads me to think I know what the problem is. The radiator core which has also recently been replaced. I have flushed it and washed it to no avail, however what I noticed is that the core they used has mighty big gaps between the fins so I looked up the core details which led me to an Australian manufacturer of cores and they list this core as having 6.5 fins per inch, while nearly every other radiator core they make for cat machines lists 9 fins per inch and they list a lot of cores. So does is sound feasible that they installed a core that the manufacturer puts in the incorrect number of fins for the application, most of the air getting blown through does nothing as it goes no where near the fins. The core is a 4N6298
Wondering if it actually is getting hot. Have you checked the temp with a IR temp gun at the thermostat.
Yes, check the temp of the thermostat housing going to the radiator, and the water pump inlet coming from the radiator. When the temp is as high as you dare run it. Those temps should tell us something, assuming the radiator is clean inside. Have you drained the coolant to check for sediment? is it running antifreeze, and what concentration? you certainly don't need more than 50/50, the more concentrated the antifreeze, the thicker it is and the less heat it absorbs, pure water is a better heat transfer fluid. 6.5 instead of 9 fins per inch wouldn't make a difference in my world, but I don't work in the temps you work in. I'm used to a larger degree of cooling system reserve...
A good test for the temp regulator is to use your heat gun on the oil filter as it will show the drop in temp as the regulator opens, the water travels up from the water pump along the side of the engine into the engine oil cooler, then on to the trans cooler traveling down 1 side of it then passing up the other side and then entering the cylinder block, the pegging up of the oil cooler water tubes is a very common problem so I would start by checking these, the transmission cooler also has a regulator placed down in the chassis that controls the oil flow into the air blown radiator style cooler or the water cooler, so you need to use the heat gun on lots of areas to gain a good picture, water/oil coolers need stripping on CAT D6 tractors around every 3 years as they block up easily, you will need to buy a cooler gasket kit to strip and rebuild them, also check that your fan is fitted correctly, if you have any doubts put up a picture. tctractors
Thanks everyone. I had not considered water flow rate. So I gave it a run yesterday although the day was overcast and only about 20C and I was only piddling around with it so the machine got no where near hot. Here are some temp gun temperatures. Before the engine oil cooler it was 84C. On the engine oil cooler it was 98C and on the transmission oil cooler it was 82C. On the oil filter it was 91C. Here are some photos where you get to see my hands.
I found this thread. Same radiator core, similar problem. Pity the thread did not have an outcome. Gives me some temperature drop figures to test for as well. HeavyEquipmentForums Although one gets the appearance that heating issues in the D6C/D machines were more common then in other Cat machines. Or there are more of those machines still about since the internetz became common.
The temps when it is as hot as you run it will tell something, the radiator temps and the oil cooler like TCT said. The numbers in post #5 might mean something to TCT, but they'll be more obvious if you get the coolant up to or over 100C.
Have you checked the water pump? I changed one on a 3306 in a truck that was running hot and it fixed it. The impeller may be worn or slipping on the shaft.
Check the oil cooler inlet. Very common problem as TC has said.
Not checked the water pump yet. It has no paint on it so I suspect is newish. The machine is sitting doing very little, and I have not had time to pull it apart just yet.
I pulled the oil cooler out. It looks clean, but when I ran a 4mm welding rod through it a lot of rusty gunk came out of probably 50% of the tubes. The castings the water runs through were surprisingly scale and rust free for such an old engine. I pulled the cover off the water pump and it looked good inside. Impeller was tight. While the blade was off gave the radiator a good blow and then wash out. So I pulled all the engine side screens off and have put it to work. It is now running cooler then ever before, although it is also not a hot day.
Not sure what type of fan U have on it but if its on backwards that can cause overheating, it might look right and still blow air but won't be enough if its on the wrong way round. Seen that happen before.
Are you using ELC RC? Iam a big fan, a quality coolant but no dearer than some of the offerings from the likes of Super Cheap Auto.
The fan is all right and proper. I am running an ELC coolant, but it is Toyota Red ELC. I get the concentrate from a mechanic friend for his price and mix it 50:50. The Toyota red is for older engines. I did try some cat coolant in my 922 loader once. It just leaked all out of the head and I had to get a new head. The pre combustion chambers would not seal with the new coolant and turns out the head was cracked anyway. I was told that only use the Cat ELC in either new rebuilt engines or just newish engines.
FYI that's a "conventional" inorganic coolant, not an OAT-based ELC. The Toyota OAT-based ELC is the pink variety. The red coolant may well have "extended life" on the label but that doesn't make it an ELC. I'm not trying to say the coolant is your problem BTW. In my experience ELC coolants will find weaknesses in cooling systems far faster than conventional coolants. That does not IMO make them unsuitable for use in older machines. IMO whoever told you that was expressing an opinion that I personally don't agree with.
Well I liked your bit of script on the Cooler but the D6D has 2, the water flows from the water pump through the engine oil cooler then on to the transmission cooler, the water flows down 1 half of this cooler turning at the bottom to travel up through the other half of the cooler case, the water then travels into the cylinder block and up to the cylinder head were the temp gauge is fitted (Non electrical) ether gas filled. tctractors
Sorry I forgot to mention the transmission oil cooler. It was very new and the internals were in pristine condition. I will just have to wait and see what summer brings, it is bloody cold here now. The nights get down to 9C. Interesting about the Toyota coolant but it works well for us. I can see how with people with newish machines working full time the Cat ELC would work well. Now I have to move onto my fuel pressure problem
I'm wondering what u found in the end that has rectified the problem. An engine over heating problem arose in our cool running D6D, and did i find some problems. Front crank seal leaking onto the fan belts, crank pulley fell apart when I removed it, thermostat seized just a little open, radiator cap so worn there was almost no rubber left on it. Still overheating but not so often ??, then I noticed coolant on the head behind the exhaust manifold, and saw there was coolant at the bottom of the top radiator hose, and concluded it was running down the hose and onto the head. Fitted a new hose and stopped the leak, still not cooling like it should. Then they let go, nothing like a very cold winter to bring o rings undone. The Pre combustion chamber o rings were leaking, just a little, that was the coolant on the head, and I zoomed in on them straight away but they weren't leaking, well not at idle while I was looking. When they finally let go I couldn't keep water in the radiator long enough to video them leaking. I replace the chambers with new ones, including o rings, along with the exhaust manifold and studs, all injector lines and one of the primer lines. Now she runs like a cat, cool as, and all her work is in the mountains. So glad those pre combustion chambers didn't continue past the D.
I had the same problem on a 980B loader. Orings would cook and leak. The problem was a badly blocked oil cooler. TCtractors told me it about the problem.
The thing that is the main cause of the P/C seals leaking is the oil coolers pegged up with crap, I would not bother sealing any chambers until I had stripped and cleaned the cooler cores. tctractors
I had the same problem with my D6D, never did get it figured out before I sold it . Someone told me it might be a pre cup issue ??
A few points to think about, firstly on the Truck water pumps the impeller was often a bit of plastic and would heat up and spin on the pump shaft, the D6D was built with PC and DI engines, water leaks from the Pre Chambers near always are caused by the heat exchanging oil coolers, the transmission also has an air cooler section that comes into play via a temp' regulator, the fan is a blower fan blowing air through the rad', so if you have checked the air filters, the oil coolers? the water pump, the fan, the temp regulator (they do change type) things would point to the radiator or sludge in the cooling system, steam cleaning the rad through with the grill plates and fan guards removed, if it still gets hot its sludge in the water space. tctractors.
I am having similar issues with our D6D. These motors did not have the plastic impellers? I have had the oil cooler temp as high as 230-235 Fahrenheit while the engine coolant temp was 210-215 when measured with a IR heat gun. There is no visible leaks from the water pump or anywhere else in the cooling system. When the machine is not rev’d out the heating problems isn’t as bad but when working under load and rev’d up it heats up.
What are the temperatures at the inlet and outlet of the radiator.?
When was the last time you looked through the radiator? use a light on the other side, to see how much dirt is plugging it up, not just to see light. Take the temps when the engine is hot like that, 210 or so.
Check your oil cooler very common problem. It was the OP problem.
Well finally got a chance to run the D6D today for a few hours. It was a warm day, the radiator had plenty of water in it, it was reasonably hard work in hills. A couple of hours in the gauge just made it to the red and suddenly spewed a heap of water out the cap. Then proceeded to run as hot as it always did, at the end of the green zone, cooling down when the load went off. I wonder if I should get rid of that silly transmission radiator cooler that is always semi blocked up and put a full width radiator in it as that is what was fitted to the same series a year or so after mine was built. And pull the precombustion chambers and look at them. I know going by where the glow plugs are located, they were not installed with the correct shims.
When we had this problem the oil cooler was really plugged up. Tony (TCtractors) said after cleaning it the radiator often becomes plugged as well. That's exactly what happened to ours. Since our machine was onl used for snowplowing. I did a redneck fix. We cut a hole in the top of the radiator and cleaned out a bunch of junk. Then rodded the tubes with a wire fish. Then taped some holes and made a nice cover. It worked well it started getting warm a year later repeated the process and it never overheated again. It's better to have it cleaned if you use regularly
RC, re D6D radiators, later 31X have a much bigger oil to water transmission cooler than the earlier ones oil to water, and then oil to air. Ive got both models and both had overheating problems. Solution was clean trans coolers and new radiators. End of problems. Trans coolers only cause problems if they climb in heat first. And then engine cooling systems can,t handle it. My problems were engine temp climbing first. Had radiators out and dissambled in later one twice before i bit bullet and replaced core with a new one. End of problems. Earlier PC one i didn,t muck around replaced core, and cleaned oil cooler, also end of problems.
Sorry for the slow reply. I looked up the parts book and yes it shows a smaller and bigger oil cooler, mine is the smaller as expected. I have not been using it lately as other stuff has got in the way, but finally got around to putting the rake back on for some new adventures. Blew out the radiator and I was surprised how much came out despite it looking clean. I think at the end of the day the core with the wrong fins per inch is going to be the main cause of the overheating problem. Given it was made by the largest supplier/manufacturer of after market radiators in Australia, beggars belief they got that model wrong. Just has to be my luck. I will keep using it for the time being and just keep an eye on it.
Well it is a year later and this year was one I would rather forget so the dozer did not get driven much and I did nothing about the overheating problems. As things have improved a bit I am back onto this problem as I have been driving it a bit as weather conditions have improved. I have started inquiring about a new core. Not cheap it I want to go quality. For locally made brass somewhere around $5000. Steel aftermarket only $2000. The radiator fellow I was talking to did not think 6.5 fins per inch verses 9 fpi would make a massive difference once the 9fpi radiator started to get blocked from debris. He said that was the compromise for increased FPI. Easier to block up from trash, and you also lose air flow because there are more fins to block the air. In saying that the cat specs are 9fpi. In any case as it is nearly christmas time, a lot of industrial businesses are going to shut end of next week until the 8th January, so I can not do anything there anyway in a hurry. I have also run it with no radiator guard on. Today I had my temperature gun with me and am getting no more than 5C difference between the top and bottom tank. Hard to get a good measurement, but sometimes it was as low as 3C. I also found out I am losing a lot of air flow between the gap between the trans oil cooler and the engine cooler, and I need new rubber seals around the fan and there is also some air bypassing around the radiator. In fact I was surprised how low an air flow was going through the radiator compared to blowing through the gaps. Then there there is also the issue of air exiting the radiator guard, hitting the blade as it is up high dut to the clip on stickrake, the air going down then swirling and getting recycled through the radiator again. I want to deflect the air upwards as it exits the radiator.
RC, I haven't seen any photos of the internals of your cooling system. Does it show clean metal or rusty, scaley, metal? Scale is a hidden burden in cooling systems, initiated by hard water with minerals in it - even if you're using a good quality coolant. Always use distilled water if you need to add water to cooling systems. Scale is an excellent insulator and as little as 1/16" (1.6mm) thickness of scale can stop up to 40% of heat transfer. To get rid of scale, you need to clean out the system with a strong acid or an amine treatment, so that clean metal is again in contact with the coolant. Scale Formation - Penray A diesel engine generates enough heat to warm a seven-room house during the winter. It must shed some of this heat to operate efficiently and prevent severe engine component damage Two-thirds of this heat is lost through the exhaust and through the engine work. The remaining third must be pulled... penray.com
Everything I have pulled apart has been spotless inside.
I also found this old post. In 1981, the upper elbow was changed to restrict flow through the radiator to cool the water more, as before it flowed too quickly. Mine is a 77 model. My D5b sa and D6D sa | Forum - ACMOC The Antique Caterpillar Machinery Owners Club (ACMOC) was founded in 1991 by a small group of enthusiasts who all shared a similar passion, the legacy of antique Caterpillar machinery. www.acmoc.org
RC, the discussion we had on ACME about the upper elbow size reduction for the 3306, is here ..... https://www.antiquecaterpillar.info/threads/underpowered-3306.9135/
Thanks. Just reading a Cat publication on engine cooling (Know your cooling system SEBD0518-09) and low turbo boost pressure can also cause overheating issues. Baffles for the radiating cowling I need are 3 of 1P7786 and 1 of 1P7785.
I priced up the baffles, If I recall correctly Cat wanted over $400 for one and over $150 each for the other 3, not all were in the country anyway. So I was going to get some rubber belting and cut some out of that, but was not too keen because rubber is pretty soft and has the cotton reinforcement in it. Then I recalled mud flaps are pretty stiff and apparently they are made of urethane plastic. So off to the truck parts shop today and around $25 for a mudflap, and cut some out of that. To get the right curve for the fan, I drew up a template and 3D printed it. The mudflap was beautiful to cut, much better then rubber sheeting. Upon installation I found I was a bit too generous with by fan dimension and the fan was hitting the rubber. Under a minute later after starting the engine I had it cut to perfection with virtually no gap between the blades and rubber strip. I also made up a plug to put in the thermostat to top tank tube. 1.2" diameter as per the specs. I did give it a run this afternoon and while it seems to be running cooler, I think the main problem is the radiator air hitting the stickrake and blowing back around and getting sucked through the motor. So I am going to make a wind deflector that will bolt onto the radiator guard. I hope that will be the final piece of the puzzle.
Smore pics.
RC, there's a lot of grassy fluff and trash in that core, you need to give it a good squirt with a firefighter hose, with a nozzle on it.
A reversible fan would work well in that application
I see a 20% plugged rad and a fairly worn top pulley causing possible belt slip.
I concur. That rad won't be flowing air worth a **** in the arrowed area. I wonder what sort of condition the other pulleys are in.?
The belts are not bottomed out in the pulley, there is plenty of room for them and the radiator core at the bottom shows sandblasting of the fins mostly, yes they are damaged there, but it is not completely blocked. I did blow it out after I fitted the new baffles.
Are they the correct belts.? They are sitting awfully low in that fan pulley. Do they sit the same relative way in the crank and tensioner pulleys.? I don't doubt what you are saying, but the photo you posted shows a radiator plugged with trash in that general area. As @Mobiltech menioned, that won't help with cooling.
Going back a little bit I noticed that you gave the Part Number of a replacement radiator core as 4N6298. That P/N is not listed for any flavour of D6D that I can see. What's the S/N of your tractor.?
It is an early 31X. So that radiator fits from 31X1 to 31X1011. After that they went away with the air to air, air to water combined converter cooler and just had a full length radiator and bigger air to water converter cooler. I am in denial about the core and going for cheap and cheerful fixes first before I drop 5 grand on a radiator core.
I couldn't agree more. If I was in your position I think I'd be having a close look at the pulleys because, unless those belts in your photo are non-standard, they are sitting too low in the fan pulley despite the fact that according to your inspection they are not yet bottomed out in the root of the grooves. Check your messages. You have mail.
Thanks. I got my air deflector contraption made and bolted it to the front. It certainly deflected the air and now nothing goes around the sides, but seemingly little difference to engine temps. Converter is 3/4 into the green and engine temp gauge is showing on the edge of the red. I checked the belt. It has been fitted with a 17A belt, so 17mm wide, while the parts book lists a 7M4707 which specs out to 22mm wide. I could put new belts on it and see I guess. Had another look at the radiator and I dunno, yes it has some fin damage, the sort of damage you get from pressure washers and general fan blast but I have seen plenty of worse radiators. I am sure the engine is down on hp, so uses more fuel at lower revs creating more heat, it uses oil and needs to be heated to start it when cold when it should not need heating at all, but does not blow black smoke or fluffy smoke except at the usual revving up stages. I am still looking at the wrong fins per inch core that has been installed and thinking hmmm.
When the belt grooves get worn, the taper of the grooves usually wears the sides curved and not straight so the belts lose some of their grip even though they are not bottomed out which may cause them to slip and glaze.Putting new belts in worn pulleys usually causes the new belt sides to become rounded like the worn grooves until they slip and glaze too. The only answer is to replace the pulleys or if possible re-machine the grooves in the old ones and use new belts. Re-machined pulleys usually require slightly shorter belts
If I were to get a new core, choice is steel, brass or copper, increasing in cost from steel to copper and also copper has something like 8 times the thermal conductivity of steel, brass only about two times. Copper is the softest, while steel the toughest. From what I can make out the cheap mass produced aftermarket ones are all steel. I can get one of them over half the price of a custom made steel one.
A steel core will give you best protection against sandblasting at the expense of lower heat transfer. A sandblast grid in front of the core is useful to prevent fin and tube damage from sandblasting. A copper/brass core with a sandblast grid will provide the best performance overall. All these older D6's and D7's run hot. Their cooling systems are marginal at the best of times, and your hot climate tests them to the max. See if there's room in the hardnose to install a larger dimension radiator core. It may involve a bit of additional plumbing.
You may also like to inquire about a Mesabi tube radiator conversion. They're not cheap either, but they have the advantage of improved cooling ability, the ability to easily replace individual tubes in-situ, and they have better vibration resistance ability, as the tubes are rubber-mounted.
Well I have cancelled the appointment with the bank for the loan to buy a new core (I got two prices from a local supplier, one very reasonable at $3600 for a locally made custom one and the other @ nearly $8600 for them to import and supply a genuine Cat core which surprisingly is $2000 more then one from the local Cat dealer. I pressure washed the core with a little dinky Karcher K2 pressure washer. It is a freaking awesome little bit of gear and stupidly cheap and if it is worth anything I can recommend it. I also tightened the belts, and just installed the air deflector with no radiator guard as I am not doing anything that should damage the radiator unless I go full retard. Dramatic difference in temps and I did not get the radiator spotless as I ran out of water as I only had 40 litres. Engine was running half to three quarters into the green, and converter was slightly cooler as well about half into the green. It was not hot hot this afternoon. The dozer itself ran like a champion. Quick and snappy gear changes. Not sure if I had positive bias going on as I could see it was not getting hot or it was running better My only issue now is grass trash getting sucked on and plastered over the radiator. I do have engine guards for the machine that I took off for better airflow. I remember an old contractor we got at times that ran a late model 10K D6C and his machine had covers over the engine that extended up so there was probably only about a 10" gap between bonnet and this guard he had. I have seen D8H's that had full length fenders as well, not that I am doing that. Other question is are Cat belts worth it? $281 for a set of three (not sure why three as it only uses two) They are only CX section belts. I can get them elsewhere. One thing that could be done is for improved cooling capacity, install a full width core) the tanks are built for a full width core but 4" on one end is not blanked off for the air portion of the converter cooler. Then you could get a generic oil cooler from somewhere else and mount it somewhere, cooled by electric fans. Not going to be doing that, but it would be possible to improve the cooling capacity. I know the air deflector looks rough as guts. I did a quick hash job just for proof of concept. It certainly works.
Cat belts are no better than any other good brand name, I use Gates belts mostly. Give me the belt part numbers you want, I might have something. I've got multiple boxes of new Cat belts. You can't beat a good regular pressure wash through the core. I use a 1000 litre tank and a 50mm firefighter with a centrifugal pump, a good length of 19mm hose - and a nozzle made from the tapered leg of a steel kitchen chair! The nozzle goes down to about 10mm diameter. Crank the little petrol engine up, throw a handful of powdered laundry detergent (your choice whether to use OMO or SURF, depending on how clean a wash you desire!) - and when that 1000 litre tank is getting well down, your radiator core should be nice and clean! Perforated engine side screens are the only way to prevent sandblasting and a core filled with trash.
This D6D has the factory perforated engine side screens, but along with the side screens fitted from the factory, you also get a fully perforated bonnet (hood) to ensure maximum air flow. This is not shown in the Grays photos. Caterpillar D6D Dozer Auction (0010-5044832) | Grays Australia www.grays.com
Those screens are the same as mine. I have the perforated hood as well.
What Part Number is the set.? I can break that down to a P/N for a single belt or maybe be able to find a different P/N for a set of two.
I recently put a newer style transmission cooler on a 977 and did away with the one beside the radiator had to put hydraulic hoses from cooler as the steel lines would not work but it is doing great
For machines S/N 31X1-1496 I show the Belt Set as 7M-0185 which is a set of 2 belts P/N 6H-5705 for an individual belt. This appears to be for the sound suppression option. For engines S/N 44V12220-Up (still searching under 31X-prefix here) the Belt Set is shown as 7M-4707 which is a set of 2 belts P/N 4M-4513 for an individual belt. I can't see a set of 3 belts listed anywhere.
The 7M4707 comes up as a set of three on my screen 7M-4707: Cogged V-Belt (Set Of 3) Width: 22.3 mm (0.88 in) Brand: Cat $218.03 (AUD) Yes that is another option. But you need the part the bigger trans heat exchanger bolts onto as well. A 7N3340 bonnet. Then the bigger 7N3521 heat exchanger. My current heat exchanger is newish going by the fresh yellow paint on it, and it was spotless inside when I was checking that part out. But there are options for improved cooling capability beyond what the OEM designed in. Depends how much money you want to spend on a 45 year old dozer.
In both of the resources I use regularly it comes up as a set of two belts. Strangely enough in Cat Parts Store it says a set of three belts but shows a photo of two - ***.? EDIT: The belts are originally an inch size. Length 80.0" x Width 7/8".
Both our 7H and 6R have this style of slanted, hinged two piece screen. They work well and allow quick access to wash/blow out the rad. If I was making them from scratch I reckon I would put a bit more slant on the fins to give a little more protection from sticks etc.
Nige, this is what I find re the belts .... 4M-4513 is a non-existent part number. 4M-5413 is a V-belt with a size of 71" x 15/16" (1803mm x 23.8mm). 7M-4707 and 7M-4709 appear to be the same belt - 70.98" x 0.88" (1803mm x 22.35mm) 4M-5413 is listed as interchangeable with 7M-4707 and 7M-4709 on some sites. The set 7M-0185 is listed as 2 belts on the Cat Parts Store sometimes, and 3 belts at other times. The photo always shows 2 belts. The set 7M-0185 on the CPS shows dimensions as 74" x .88" (1880mm x 22.35mm). Aftermarket suppliers of 7M-0185 state the same length but the width as 15/16" (23.8mm). Another P/No that has appeared for 7M-0185 is a single belt, 6H5705. But the CPS says 6H-5705 is obsolete, and it has been replaced by 7M-0185.
Sorry, dyslexia. 4M-5413 in SPS is listed as 1803 x 22.3 (71" x 7/8"). Again my error in crunching the numbers to convert from mm to inches. I was certain that such an old Part Number could not have originally been a metric-sized belt. Apparently 7M-4709 Belt Set was originally 3H-9861. At CHG01 3H-9861 was replaced by 7M-4707.
That is certainly a good design. Are you getting much rain? Getting good drops here. Another 30mm last night, and 28mm last Saturday. It is just a tad green at the moment. Got the truck bogged twice today. Just spinning on top.
RC, I had a good look through my boxes of Cat fan belts, and sorry to say, I've got nothing in your size. You're just going to have to trot down to your local Cat dealer with a big jar of lube, and hold onto the counter, and wear the $281 ar*e-reaming for your new Cat belts. I know you can handle it - you're a big cattle baron anyway, and those cattle prices have been over the top for the last 2 years, so I guess you won't notice the dent in your bank account. Back in the late 1970's, I recall seeing a crusty old dozing contractor I knew, leaning on the parts counter at Wigmores Tractors, when I went in to pick up some parts for one of my D7F's. Old Vern had a booming voice at all times, and as soon as he spotted me, he boomed out for everyone to hear - "WHAT ARE YOU DOING HERE? - DID YOU PAY TO GET IN HERE??" I was a bit taken aback at this line of questioning - but he soon followed up with, "NO - YOU DIDN'T PAY TO GET IN!! - BUT I'LL WAGER YOU'LL BE PAYING DEARLY, BEFORE YOU GET OUT!!"
Around 150mm over the past five or six weeks. Raining again this evening and the forecast sounds promising but we don’t need what they’ve had up north over the past week. Our country doesn’t look as good as yours yet but we’re getting there.
So all this and the radiator just needed cleaning???
Pretty much……. While the belts are off it might just be an idea to check the profile of all the pulley grooves for signs of wear. @.RC. - that copy of REHS1063 I sent you has a section devoted to inspection of pulley condition. I suggest you use that to check yours because it could be a waste of time putting new belts on overly-worn pulleys.
Hmmm…, we had Cat give the 7H, in the above pic, a TA2 inspection before we bought it. Dealer had fitted new genuine belts, so belts and pulleys were given the OK. With less than a day’s work they started squealing and no amount of adjustment would stop it. Fan and alt. pulleys were completely clagged.. crankshaft wasn’t too bad.
Not really. It has been determined the radiator core is wrong to begin with. It is going to run hot regardless. The belts are wrong. God only knows why 17A section belts were fitted to c section pulleys. There are the baffles around the fan which are now fixed. There is also the 1.1" hole restriction to slow water going through the radiator. Also the wind deflector, to stop air recirculating. I do not think it is a wasted thread as I have read many a thread in here, where someone with an issue asks advice. Gets it, then we hear nothing back and the end result is a mystery.
It would have been nice to do the changes one at a time with temperature measurements in between, but it doesn't work out that way very often. The restriction still bothers me, just as Julian noted in the Acmoc thread. There are plenty of perfectly reasonable explanations of how adding that restriction could improve cooling, but slowing the coolant down in the radiator giving it time to cool off more IS NOT a reasonable explanation. That is a massive error in heat transfer understanding, and makes Julian and I at least, suspect everything about that suggestion.
It IS a reasonable explanation - and Cat, as well as many cooling experts have espoused this as fact, not theory, for many decades. It's well known that removing a thermostat (regulator) from a cooling system that is overheating, only makes the problem worse, due to the engineers calculating a certain level of flow restriction created by the thermostat installation. https://www.motortrend.com/how-to/preferred-engine-coolant-flow-rate/
By the same token that theory would say my radiator with the bigger gaps at six and a half fins per inch should cool better as more air can flow through it then a nine fin per inch radiator.
Except it violates the basic fundamentals of heat transfer. As Julian pointed out well enough that I can't improve on. Bringing motortrend magazine into a technical Cat discussion is like going to a Dodge Ram forum for expertise on a technical Cummins question, sorry, not helping. The article's strongest argument is preventing laminar flow, EXCEPT laminar flow is from slower flow, turbulent flow is from faster flow. There are plenty of myths that have been repeated long enough that they are accepted as fact, that's not much proof in my opinion. Removing a thermostat is a whole different subject, most thermostats we're talking about are bypass type, or a three way valve, open one way cold, open the other way hot. Removing a bypass thermostat opens a short circuit around the water pump reducing flow through the radiator. The article mentions some factual info regarding removing a non bypass automotive thermostat, but that's irrelevant to this. 5:30 for an explanation of bypass thermostats, the rest is standard cooling system info, and a good measure of salesman's claims as well. I'll see if I can find an equally good Cat version.
Wrong. The slowing theory would say that a good coat of dust and lint will improve your radiator cooling by slowing the air to give it enough time to absorb more heat. Using the SAME radiator on the same engine, moving more air through the radiator by moving it faster will make the radiator lose more heat. You can usually only change one variable at a time to have a valid experiment, adding more surface area is not the same comparison, just like I suggested above.
People can believe what they want to believe. I just want to have a reliable machine with cool air conditioning that I can drive all day in summer.
A copper rad can be dipped in solder? (I think) to strengthen the fins. I had that done on my rad. when it was re-cored. I think someone makes a comb for straightening the fins as well. Having all the fins allowing full air flow makes a big difference. Belts sitting higher on the pulleys will make pulleys spin that much faster. I'm not sure if having the fan shroud really tight to the fan is a good idea? It might be better if there is extra air movement outside the fan so the entire rad. surface is utilized. The other thing I'd be concerned with is the mud flap material getting brittle from the heat and cracking and/or potentially breaking. I may be off base but these are things I'd be concerned with.
It got a good run today and it while it never got near the red, it was only 32C today and it still ran hotter then it should have. I did have a good day though until. Just on dark, in a hurry to just get that one more tree sideways on a slope close to a gully I knew it would not reverse out of with the rake on the front, the downhill track dug in in the soft soil, and the machine would not turn and then the track came off the idler. At least it went inwards against the nose. Crowbar time tomorrow.
That really sucks but it's usually easier to pop back on the idler. Might have to back off the track adjuster and tighten it back up after the track is back on. Too bad it's not in a spot where you could hook a chain to another vehicle. Years ago a neighbor dug a drainage ditch for us. He used a JD555 loader for finish shaping and a track came off. He hooked a chain to his 4x4 pickup pulling the track towards the idler at about a 45 deg. angle. He pulled with the truck and had me slowly drive the loader forward and the track popped back on in about 2 feet. It sounds like it might be OK as far as temps. are concerned now. Did you check with a heat gun at various places?
I used to use a bottle jack against the dozer chassis and against the top front of the track, for when the track came off on the inside. Angled in a backwards direction to start with, then drive forward a bit, so it pushes the track outwards. Block it with timber and remove the jack and repeat. After 2 or 3 times of this, the track usually pops back on. You need to investigate why it came off. They usually only come off if the track is too loose, or if it's badly worn.
It came off because of a clip on rake, a slope and no roller rock guards to help guide the track straight and soft dirt turning into mud and going in reverse so all the track slack is underneath. But with OzDozers suggestion of blocks of wood and bottle jacks and one inch at a time and a couple of hours and lots of slipping in the mud as we had another 20mm of rain last night and sweating as it we seem to have 120% humidity at the moment. It finally came back on took it back to the fuel bowser.
There's a simple reason the track came off. The conditions you were driving in may have contributed but only a small amount. Track was maybe a little loose or worn enough (along with the idler) or it's a little snaky. Maybe all of the above.
A new core it is going to have to be. It is just hopeless. 33C ambient temperature and when it is already at warm operating temperature it will be run itself into the red just driving up a hill for a few minutes.
RC, did you get a reading of these temps?
RC, are you going for the full width core? It would be my choice.
Yea, it drops about 4 to 5C over the top to bottom, if you can trust my $15 temperature gun. It is a bit all over the place. Also if I fill the radiator right to the top, it will blow some coolant out the radiator cap overflow once operating temps are reached. Once the level is down a bit it no longer does it. I would like to, but the bottom tank for the later power shift full width core shows a different part number to what I have. Mine is a 1P7812, while the later full width power shift radiators have a 4N7450 bottom tank. The wider core is a 7N3542. However the direct drive machines use a full width radiator and the same bottom tank as mine, however their radiators are only 4 core. The powershift ones are 6 core. Be nice to know what the actual differences between the 1P7812 and the 4N7450 are. The cost of them is surprising for what I thought was just a simple casting with some minor machining. US$1500. The top tanks are all the same on all D6C and D6D machines with a standard style core (not folded core) 1P2513 I am still waiting on this holiday season to end to sort the v belts out. Waste of time doing anything until the 8th January.
just remember if you go full width core you will need different top and bottom tanks and different centre plate as well. . . Its not a direct core swap. Also the trans coolers had a different centre adapter or bonnet between the trans and engine oil coolers, and different bottom cooler cover. Will get pricey adding all that up. Ive got both style D6D so know differences 1st hand
Yes, to change fully to the wider core is not just that straight forward. If one wanted to improve engine cooling, adding another air to air torque converter cooler would do a bit. That would lessen the load off the air to water TC heat exchanger. In this day and age there are plenty of add on electric fan powered hydraulic oil coolers. In fact just thinking, that may be the cheapest way out of it. $1000 for a cooler and hoses. Compared to $4000 for a new core to replace a very good condition core to begin with.
Pays to shop around. D6D (3X) Caterpillar 3306 Diesel 1988 - 1977 Belt - Fan & Alt. ........................................... 4M5413 TR30710 Two new Gates 22A1805/TR30710 belts, $50 each from the local bearing shop. Even Tilly's price was $200 for the pair plus postage. Got to get my crane onsite to pull the radiator now, and the road is a bit wet. I also surmise that with the 6.5fpi core and the TC cooler is the proper 9fpi, the fan is going to be blowing most of the air through the main radiator due to less resistance. So the TC would not be cooling at high efficiency either. Plus with such big gaps it would blow more air (and use more engine hp to run the fan), which may be more then the side covers and perforated bonnet were designed for. All I can see are disadvantages for the lower FPI radiator.
The whole theory behind more FPI is that there's a lot more total cooling area available to the air, with the increased number of fins. But that has to be balanced against the finer level of fins becoming blocked more rapidly. There's a good balance between the number of fins, the level of airflow you can get through, and screening that stops the worst of the fin-blocking material, without reducing airflow through the core. I STR that Cat have figures available on minimum airflow requirement through the core (CFM or LPM), as measured by equipment mounted in front of the radiator when the engine is running at full throttle.
I seriously do wonder why they had the work experience kid design this stupid idea of an air to oil hydraulic cooler and as well as an water to oil cooler, when I do not think they did that any other model dozer they built during that period. Oil went everywhere as expected.
Here is the oil cooler. Sandblasted to buggery. Decisions decisions. $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$, i still think it was a stupid idea by caterpillar. https://www.ebay.com/itm/291581977052
That looks more like grass and similar crap going into the fins than sandblasting. The rad in my 931 loader was sandblasted in the top corners from dirt, sand, clay and what ever else I was loading. Material or lumps would fall on the front of the hood and slowly break up and work through spaces between parts of the hood like the door to check oil and coolant. The fins were worn down like they were sandblasted. Your rad looks more plugged from grass and stuff than sandblasted. Something like window screen to prevent grass and stuff getting sucked in by the fan would help. You could clean it as necessary.
It could be, but the fins are well worn away compared to where they are protected by those angled cross members. I just stuck a magnet on them and everything on the TC cooler is steel, fins and everything. I could probably machine those damaged fins away being steel.
RC, watch out for the eBay "Global Parts Zone" cooling products, they're all Chinese and the replacement oil cooler they're selling is almost certainly 100% aluminium. They are selling "Cat replacement radiators" for traxcavators and dozers using the original Cat part number - but the radiators are 100% aluminium, too - not the brass tube and steel fins, or brass tubes and copper fins, of the original factory fit.
Yea, I was just using that link as an example for the part number. I expect down here it would be a $3000 part, not that I plan to get a new one. Going to try to salvage it a bit.
You can buy fin-straightening combs, but a small pair of needle-nose pliers is a good tool to use on buckled fins. It gets pretty time-consuming and tiring though, straightening 40, 50, or 60 bent fins! https://www.repco.com.au/tools-equipment/automotive-tools/cooling/repco-fin-straightener-cleaner-rst18/p/A9706975
Replaced mine a couple years ago, rust out at the bottom. Forget where I bought it but wasn't that bad here. Think it was under $500
You won't find a fin comb with that spacing, they're made for AC units. But it won't matter, you'll be doing one fin at a time and it's not that slow. You want a steel comb with a hook to it, that will pull off some of these bent over edges and straighten them if they won't pull off. Then de grease and hose till clean, and paint it, that's what I do anyway. I've never seen sandblasting like that, but I agree that's what it is. Or possibly some rust from the paint scratches then bending from the grit.
I think you are getting combustion gasses in the cooling system. I would clean that radiator/cooler assembly, and put it carefully back in the dozer. It should not be blowing the coolant out the radiator.Those cylinder gasses are so hot,and under such pressure, when they enter the cooling system, it gets hot fast. If your lucky,you may just have a loose pre-combustion chamber. Good Luck with that,its a nice clean looking machine.If you run it without all those attachments,on it, does it still overheat?
Yea possibly, but it only does it when the radiator is topped up full to the brim and there is no room for expansion. Then only it pops out water once or twice as it heats up, then the level remains stable a couple of inches down from the top. I had a bit of time so got out the 9" angle grinder onto the TC cooler Well actually it was only a 5" with thin cut off wheel and then a dremel with a tiny cut off wheel to tidy things up. Looks like it will work a treat on the damaged fins. I can see daylight through it where none existed before. Especially after I blew it out. and it is surprisingly quick to do.
You know of course, that a Cat engineer is now going to tell you, you just reduced your cooling capacity by 5%, by cutting back all those fins?
I'm just going to make a couple of "observations", I know I'm probably nowhere near qualified to respond on this thread. Are you ABSOLUTELY certain that the temp drop through the radiator is affected by the radiator, and not flow? Like maybe a smaller restriction could be tried to slow flow down more? Has the overhead been ran recently? Apologies if I missed it in the thread, I just browsed through it. Do we know if the fuel pump has ever been messed with? Timing OR fuel delivery? Again, if this has been mentioned, tell me to go sit in the corner. Lastly, is the exhaust system been eliminated as a perp? I had a muffler on a truck with the baffle broke free and created a pretty substantial restriction in the exhaust causing high exhaust temps and ultimately high coolant temps. That muffler appears to be beat to ****. Food for thought.
There is very recent post of an excavator with a bad muffler that cooked the seals on the hyd. tank causing loss of (tank) pressure and pump cavitation. Bad or damaged muffler or exhaust pipe leaks could put a lot of excess heat under the hood.
We know with certainty the radiator is wrong. In my research I found this, pretty much the same machine with the same heating issue and a similar low fin count radiator. HeavyEquipmentForums . While there was no resolution there, there was another thread for the same machine a couple of years later. while again no resolution, the radiator was replaced with a proper one. HeavyEquipmentForums I can say the engine has not been turned up. It drives like every other Caterpillar dozer of that era. they were never renowned for being able to win any 1/4 mile races, only endurance races. Muffler is clean. Could be timing. At least this should let a bit more air flow through. If I had the skills, I would debraze the top and bottom tanks and simply spin it around. The fins on the other side are near perfect still. But I am not up to Pakistani truck rebuilders skill level yet.
This one is for Nige.
Can you see the difference between what you have now and what you had then.? Do the new belts look the same in all the pulleys.? You probably don’t have a phototach but I’m willing to bet that new belts are probably giving you a decent increase in fan speed - although with the condition of the radiator and the oil cooler it probably makes no difference to system performance in the grand scheme of things. BTW did you get that document I sent to you regarding cooling systems.?
Yes the belts ride high in all the pulleys now. The radiator core is currently at the radiator shop getting measured for a new core. The only two local producers of radiator cores both copied each other and make then at 6.5fpi,o I have to get a special order one made.
re the oil to air torque converter cooler, only gets oil sent to it after the cooler bypass valve opens. Is same function as a thermostat. If your torque converter oil temp was rising before the engine temp, consequently putting all its heat into the oil to water system. Bypass valve could be faulty. Mind you this is easy checked by putting a hand on cooler pipes to oil to air cooler. If they are cold or warm. Cooler bypass valve is meant to open at 85 C oil temp The new radiator core i put in my earlier PC engine D6D, same as yours, had the wider spaced fins in it compared to the closer space fins original one that came out of it. New core solved all the problems i was having with it. And no troubles since
The bypass valve seems to be working Merv. I am also not surprised in your climate a lower fin count radiator would be fine. It works fine here in winter, which would be similar to your summer.
New radiator core is ordered and getting built. Have got the required gaskets waiting to be picked up. Do people normally use gasket goo on radiator gaskets just to make sure they do not leak?
Ya
Yes, after pulling the tanks apart, I will be using gasket goo. Someone has made up a "spacer" plate and soldered it onto both tanks. Looks to have been a few rust repairs done. I half expected the tanks to be cast iron, but they are just pressed sheet steel. I would imagine like all old machines back in the day no one used rust inhibitor in the coolant. The filler cap was done up so tight I had to use stilsons to undo it. I have seen that before as the sealing portion is corroded and rather then fix it, it just gets done up tighter. I brazed and machined it back flat. Not too impressed with the chatter marks but it was to be expected.
Could you smooth it out with a file?
I have heard of the water pump impeller coming loose. It pretty easy to check you just need to drain antifreeze and remove the water pump cover to gain access to the impeller Also if you’re you can get a hand infra red temp gun and check the temp of the top rad tank and the bottom tank, there should be 10 degrees difference with engine warm and running. If you have more than 10 degrees means plugged rad. Externally. If you have less than 10 then it’s plugged internally or other circulation problems
Most cases you can remove one of the water pump hoses and stick a thin screw driver or stiff wire into the impeller. Then turn the pump and see if the wire can stop it
Welcome to the forum. You're not too far from my property. It's just past Sturgeon County in Thorhild County West of Opal.
Nah, just redo it with a sharper cutter. If I knew how to tig weld it would have made it a lot betterer. I still have one part of exposed cast iron as I found it difficult to build it up with the oxy, it would just stay flat. That has all been checked out.
RC, you need to soak those radiator tanks in an acid bath to clean up that corrosion.
And after a dip look for any areas that may be about to rust through. Radiator tanks also dissipate heat too so removing the existing rust/corrosion is beneficial from that aspect. Every little bit helps
Yea, it is more red paint you can see than rust, but a bath would not do any harm. It will be DIY, I would not even know who locally would do acid bathing but no doubt they would charge a mining tax. Might even do an electrolysis bath. I already have all the ingredients for that.
I use citric acid for my acid baths, it's safe, effective and simple and it doesn't eat into good metal. Once it's pulled from the bath, all it needs is a pressure wash. I spray the cleaned item with about a 10% solution of phosphoric acid ("Ranex" - get it from Bunnings) and this prevents flash rusting.
Thanks, not having any citric acid here at this point in time, I made up an electrolysis bath. After 10 hours I pulled it and washed it and there was a lot more gunk and rist on it then I thought. I have it back in the bath for another run at the moment.
I am not as pleasing on the eye as pkw is in this photo in his thread here HeavyEquipmentForums So here is just the new core.
RC, was that core built locally, by someone like NATRAD?
Yes locally built, the supplier told me the builder was Redback radiators whom only deal with agents. This new core has more tubes connected to the headers then the old one. I will get a photo in the morning showing it. Redback Radiators www.redbackradiators.com.au
New one a eighteen more connected tubes to the header.
Well my run of luck is certainly continuing. I went to get a tube of rtv silicone from a shop yesterday, sorry no stock, so I thought I would just get it elsewhere. I went to the bolt shop, that also sells other odds and ends. Ahh they had some tubes so saved me a trip to another auto supply store. I used it today. It came out of the tube sort of not what I expect of silicone, but it was still very sticky and a brand I had not used before. Until on the second gasket the nozzle just blocked up and I pulled out some cured stuff, then it just refused to come out. Cutting open the tube and the photo tells the story. The **** must have been sitting on their shelf for years. No date of manufacture on the tube. I might shove it up their arses tomorrow. Or just politely ask for my $50 back. Was hoping to get it all back together today and install tomorrow. I just hope the gaskets I used it on will still seal (I suspect they will). Otherwise is another $150 pissed up against the wall as the big gasket is $90 alone.
A maximum of 12 months on the shelf is the recommended lifespan for RTV, silicone and urethane sealants. I'd get right up the sellers, selling crap like that is a good way to make purchasers avoid a business.
Got my money back no problems, they said they had only had it on the shelf for eight months, but who knows how long it had been in the suppliers warehouse, or maybe this was just a quirk that only that tube had gone off, they did offer me a replacement tube. In any case I have some JBweld grey silicone now. I used to use a bit of loctite stuff like 510 or 515, but the price for that stuff has gone ballistic.
That would be a royal PIA when you're ready to do final assembly. I'd be really ticked off since my property is an hour away and even more ticked off if I had someone meeting me to help.
Well it was another $30 in fuel to get a replacement tube. I have the radiator tanks bolted on now. I have decided to make up some blanks for the inlet/outlet and when the silicone is cured pressure test it under water with air, to see if there are any leaks. The designer of the radiator tanks also did something sneaky. One bolt hole top and bottom is 5mm out of alignment with all the others. The manufacturer never picked up on this so I had to dremel a header hole out a bit.
Pretty much ready to go back in. Leak tested and a bolt not done up tight was the only temporary problem. No leaks when held at 12psi and none at 15psi which is when the pressure cap opened. I put some dense foam rubber between the two radiators to fill in the small gap and made up inserts to fit the other gaps.
As long as the foam doesn't melt. I don't how much heat different types of foam can handle though. That would just be my concern.
It is high density rubber foam. It will only see 80C max with this new radiator.
I reckon it was at least that hot out in the sun today. Good luck with it.
I was starting to put it in yesterday and it was about 35C and 120% humidity, then a brief shower came over and the sun came and bumped the humidity up to 150%.
You weren’t under some of those big falls around CQ last night?
No, long way away from here. I see 240mm south of Emerald and widespread 100+falls from the gemfields, all the way down through the arcadia valley. Looks like here at 8am it is 30C already and 80% humidity. $6/kg for steers here we come I hope with all this rain.
Another hot humid day, got it operational. Made all new side and bottom radiator baffles for it, they are not hard to make. Gave it a run this afternoon in 34C heat for a couple of hours and really gave it the beans. Looks like the problem has been solved. Could not even get it halfway through the green.
RC, what did the new core end up costing you?
It was $3900 + GST for a copper one.
Great result. Are you still going to run Toyota coolant RC? I see you can get CAT ELI, the glycol free ELC, for $91 inc. for 20 litres.
ELI is not antifreeze, and is to be used at 7.5% concentration, in distilled water or similar, so 20L would go a long ways. Interesting that it uses ELC extender, and not just more ELI. Also interesting the nitrite and molybdate levels. For those of us in the North not familiar with it: http://s7d2.scene7.com/is/content/Caterpillar/C10604661
ELI is an extremely good option for any location where engines never get cold enough to freeze. It has the same inhibitors as ELC which protect from corrosion and cavitation. In a hot climate that’s all you need. TBH I wouldn’t put coolant in any machine in Australia, only ELI.
The price that I posted is for premix. Concentrate is around $1500/20 litres.
At that price, I might be picking up a few drums. I have a few machines ready for a coolant change and why pay for stuff with antifreeze when there is no need.
Well I still have a cooling problem. I was into it today fairly well, doing a lot of second gear work, and about 2pm was when the cooling problem really got going. The air conditioner was really struggling to keep me comfy and cool I think the cab is just too big.
Do you need a Turkey farmer special?
Not sure what a turkey farmer special is, but those big old cabs take a lot of energy to cool. Well the new radiator has been a success, it ran cool all day today, something it never did before in summer. It will need a gentle blow out from the front soon. Thanks everyone for the help. I will just list the radiator gasket part numbers here for reference. Starting at the top, from top tank to adapter plate is 6n4950 From top adapter plate to top header is 6N4949 From bottom header to bottom adapter plate is 6N4956 And from bottom adapter plate to bottom tank is 6N4955
If you use it during day light hours only, could put tint film on the windows
The problem with tinting is when it gets dust on it, you would not be able to see out. It is bad enough now in the afternoon seeing out into a shadowed area, you cannot see the ground and do not know if there is a precipice ahead of you or not. Added to vision problems 50% of the glass has been replaced by perspex.
Probably why some of the old timber rigs Scrubpuller posted pictures of had goofy sunshades on them. Most were open canopy, but I'm sure it helped a bunch. Sure wish I knew how that old bugger was doing.
Might as well post these pics here that I took today.
Shimmy, I miss him too. As far as those sunshades or canopys, maybe Oz or Tones could say. The only explanation I could find on the 'net says those are to keep the snakes in the trees out of your lap. Fcuk that!!!
You mean something like this? Just an old style scrub canopy to keep the trees and limbs out of your lap. Round on top so the limbs will fall off and not sit up there. Although the newer style is square, so flat on top, easier to make I guess, but rubbish would accumulate on top I imagine. Don't own and never used the newer ones so can't say for sure. The one in the picture is a little big for the baby dozer, but I got it for almost nothing, bit of fabrication and it doesn't fit to badly.
Bloody hell it’s green there…. I thought it was looking good here but that is a whole other level!! Nice view too. Glad you got your heating problems sorted, I’ve been following your progress.