Hello. Cat D6R bulldozer, overheating. I work normally for 1.5 hours, the water temperature arrow shows the middle. Then the water temperature arrow can reach the red zone. If you take breaks, for 5 minutes (approximately) it drops to the middle. The transmission oil temperature also rises, depends on the load. Last week, the radiator elements began to leak, I changed the gaskets, cleaned the entire system, removed the oil radiator, the transmission oil radiator, the water pump. In the small circle of the thermostat to the pump there is a plug so that all the water is driven along the large circle, without the plug it heats up even faster. I live in Bolivia, the temperature here is always more than 25 degrees, what could be the reason for such overheating? D6R BRJ 2004 motor C9
Do you have a photo by any chance, especially if it shows any Part Number.? Ambient temperature is one thing but what altitude above sea level are you operating at.? Also what type & viscoisty of oil are you using in the transmssion.?
Does it have reversible fan blades ? If it does look at them carefully. Sometimes one of them may not have locked in either the push or pull position like the others. That will enable it to turn and come to rest in a neutral position and cause an overheating problem similar to what you describe. I saw it happen on two different dozers I was operating.
With a machine serial number I could find out.
Ive also seen those fans wore out so much that the blades would turn flat even when they were locked. Also make sure belts are not bottoming out in the pulley grooves
Here is the first photo, where it is marked in red, between the thermostat and the water pump, there is a plug inside, so the water does not pass. Altitude 150-160 meters above sea level. transmission oil Lubrax Grans Tac4 50 , but before this oil also had problems with overheating. what I have already done to find the problem: 1. removed the engine head, the head surface is not curved, the gasket between the block and the head is normal. 2. changed the liners, injectors sleeve fan blades isnt reversible, The fan blades work to blow air from the engine towards the blade. The belts are OK. Second photo, the transmission temperature rises along with the water temperature, but cools down more slowly.
Have you removed and inspected the water temperature regulator (thermostat).?
Can you post some photos of the grooves in the fan drive pulleys and also of the fan itself please.
I will describe my solution to a similar problem. The bulldozer overheated after 1.5-2 hours of operation at an outdoor temperature of +32 degrees. If the temperature outside was below +20 degrees, the bulldozer stopped overheating and worked well. My problem was the poor quality of the coolant. The radiator sealing rubbers were heavily swollen and partially blocked the radiator inlet channel. After replacing the sealing rubber bands and antifreeze from another manufacturer, the overheating problem went away. Engine temperature before replacing the coolant. Radiator sealing gum, which has become soggy and has increased in size. Operation of the bulldozer after replacing the coolant. It has been running non-stop for 10 hours. The temperature outside is +32 degrees.
yes, I removed it too, but as I wrote earlier, I don't have a thermostat, the small cooling circle is plugged. And I use distilled water for the radiator, due to frequent radiator leaks. I need to try coolant. what color coolant did you use? red or green?
You need the temperature regulator (thermostat) reinstalled otherwise the cooling system will never operate correctly. Also the lack of the required chemicals in the coolant will cause rust and result and cavitation. This will end up causing expensive engine damage. In your climate what you really need is an inhibitor for the cooling system, because I’m guessing that you do not require the protection from freezing. Take a look at Cat ELI (Extended Life Inhibitor). It contains all the necessary additives without the frost protection. If you want to look at a coolant then you need low-silicate one that meets ASTM standard D4985. That will be a red coolant.
Hi. I filled the coolant and installed the thermostat back, but nothing changed. The water heats up exactly the same. here some fotos from pulley and fan. I also measured the oil pressure on the brakes. when braking or applying the brake, the values drop to zero
That tractor radiator really needs a clean, no wonder it’s heating up, also the belts and pulley’s need changing, or machine the pulley’s and use wider belts if you have enough meat, cheers
As per what @bccat mentioned above you have a number of problems that are contributing to the failure of the cooling system to maintain the correct temperature. 1. The radiator is filthy. Ideally it should be removed from the machine, disassembled, and thoroughly cleaned. Cleaning the radiator in-situ is the next thing to impossible. 2. Do I detect a missing radiator core.? I can't think how it would be possible to take a photo of the fan from the front of the machine looking through the radiator unless a core had been removed. There are only 6 cores total in the radiator. If one has been removed the result is an immediate 18% drop in cooling efficiency. 3. All the fan pulleys in the photo are completely worn out. They should all be replacing along with new fan belts. At the same time the tensioner assembly should be inspected along with the bearings on all the fan pulleys and the tensioner, replacing any that are worn. What you have is not a single problem but a number of issues which all add up to a lack of cooling system efficiency.
Hello. I think that even if the fan pulley is so worn, it cannot be the cause of such severe overheating. It's not as bad as you can see in the photo. I removed the radiators because I was changing the gaskets, I cleaned them under pressure with water and air. I took a photo of the front of the radiator when one element of the radiator started leaking, I removed it to repair it. Naturally, I have 6 sections, and they all work.
I'm sorry to tell you this but you're wrong. Those worn fan pulleys are the principal reason that your cooling system is overheating. Also it is important that you understand cooling systems generally work with little of no "spare capacity". They are on the limit most of the time, expecially in the case of higher ambient temperatures. That is why what is apparently such a small thing (the worn pulleys) can cause such a large problem.
I have seen several dozers that had folded core radiators that were very problematic with leaking gaskets and causing overheating of the engine that they were replaced with traditional flat radiators. They were new D8n's.
This particular D6N has an AMOCS radiator (first illustration) with both the inlet and outlet of the cores at the bottom. The second illustration is from a D10 tractor but the principle is the same. The "hot" (RED) coolant inlet on the LH side of the illustration passes through the "cool" (BLUE) side of the lower tank via a tube before the coolant starts to move upwards through the cores. The bottom tank is divided by a transverse baffle. I don't know if the baffle is welded or has a silicone seal that is designed to prevent coolant returning direct to the "cool" side without having to flow up/down through the cores first. It might be worth taking some inlet and outlet coolant temps. I've even seen cases where the seals at the bottom end of the cores started to fall apart and the pieces lodged in the tubes in the inlet (front) side of the cores blocking partially the coolant flow. The OP has already stated that he had leaking seals on the bottom of the radiator modules that he replaced. I wonder if some pieces of those seals have become lodged somewhere.?
Thanks for taking the time to post that image with the flow path. It is different from the folded one I am familiar with. ⬇
All I'm going to ask at this point is did Caterpillar use the buying public as guinea pigs for years, trying to come up with a better mousetrap? I mean, why all these different designs? Has there been definitive proof that one design is the best, or do they just use whatever they can get the most cooling out of with the smallest overall dimension? I, as an operator and owner, would not give a single ***** if the nose of the tractor was 6" wider/taller, whatever if it meant I wouldn't have cooling problems. @Nige , your statement earlier about there never being any spare capacity is spot on, and why machines never seem to want to cool when they get some age. The engineers can suck a fat one.
Simple answer - buy Komatsu.
Hi. Oh yeah, I'm already tired of getting these pieces of rubber out of the insides of the engine, radiators, water pump and cooler for oil and transmission oil. This time all the gaskets were damaged because of this I removed the oil cooler and powertrain oil cooler. Because of this I thought to install a regular radiator, about the same volume. So as not to have any more problems with these gaskets.
Have you checked for any possible blockages in the tubes that take the coolant into and out of the radiator bottom tank.? Note that when those seals are replaced UNDER NO CIRCUMSTANCES should you use any petroleum-based lubricant on them for installation of the radiator cores. Instead use a liquid soap. Unless you also fix the problems with the pulleys and belts you would be wasting your time in my opinion. On the basis of the photos you have posted up to now that's where the biggest problems are, not in the radiator.
All that crap on the belly pan is not helping either , acts like insulation, plus a real fire hazard, that poor tractor hasn’t had much maintenance in its life!
I’m happy to say that this is one of the most simple to solve problems I’ve seen in a long time. Your problem will be financially cheap to fix,but quite time consuming from a labour effort. You need to take out your radiator and both your transmission and engine oil coolers.They are very clearly blocked internally and externally.Take the time to clean them thoroughly. That part of the job will only cost you gaskets and time. The second part of the job is the more expensive job n that you MUST buy new fan,crank and tensioner pulleys complete with belts.You may purchase non oem pulleys at a fraction of the cost of Cat,however you must buy the genuine Cat fan belts as they are unbelievably superior to non oem. Do not underestimate how badly worn your pulleys and belts are.They are scrap. You have a leisurely and relatively cheap 2 day job on your hands. P.s all the rubber gunk in your system is down to an inexperienced fitter using the wrong type of glued and sealants. Don’t make this mistake again. Failure to take heed of all the good advice you’ve been given on here will result in endless downtime,cracked heads and a blown engine. Get on with it.
Dead right. Someobdy probably used Vaseline on the radiator core seals when they were last replaced. The resulting carnage when they fell apart was a self-inflicted wound. My only other comment is that because of the OP's location he may not have the option of aftermarket non-OEM parts for the fan drive.
They all built for a cost
I completely checked the lower tank from the radiator and cleaned it from dirt and pieces of rubber that could remain. I removed the hoses, the water pump - to the tank and another hose, also cleaned them. These rubber gaskets cost me about $ 1.5 each. I do not know what quality these gaskets are. When installing the radiators, I lubricated the inlet and outlet pipes of the radiator with a thin layer of light oil so that they do not damage the gasket, as well as the holes in the gasket so that it does not get damaged. I do not use Vaseline, sealant or silicone here. The logic of the mechanics who work here, and I think in third world countries is such, for example, if the pulley rotates with the fan, everything is fine, but when it falls off, then it needs to be repaired. In developed countries, there are some parameters or standards under which this or that part must be changed, due to the wear of the material or the manufacturer's instructions. I'll try to find these parts, if they are inexpensive, I'll try to change them. But why can't the high temperature of the transmission oil be the reason for the engine heating?
That will cause the gaskets to fail. You cannot use any petroleum-based product on them or they will fail in a very short time. There is a very expensive Cat rubber lubricant available, or liquid dishwashing soap. Either will work. I have highlighted the relevant parts in the attached procedure as confirmation. I worked for many years out of the technical office in Antofagasta for the Caterpillar dealership that covers Bolivia among with Chile and Argentina and can say that statement was not true for the well-trained, experienced mechanics that I came across. I have said this before but I will say it again. In my opinion what you have on your tractor is not one single factor that is 100% responsible for all of the overheating problems but a combination of factors. Until you have the engine cooling system in optimum condition you have no idea if your issue is caused by EXCESSIVE heat being produced in the powertrain OR if the engine cooling system is not capable of carrying away a NORMAL amount of heat produced in the powertrain. To move forward you need to repair each obvious issue one at a time until you reach a point where whatever is left MUST be the root cause of the problem. My suggestion to you is much the same as what @nicky 68a mentioned earlier: - 1. Lower the bottom guards and clean out all the dirt. It is preventing any airflow across one of the hottest components on the engine - the oil pan. It is also impeding correct airflow through the engine compartment and the radiator. 2. Clean out the radiator externally. Be prepared to replace the seals at the bottom of the cores again. They WILL start to leak again, it is just a case of when. 3. Replace the crankshaft, idler/tensioner, and fan pulleys along with (if necessary) the bearings in all the pulleys and any other parts such as the springs for the belt tensioner, etc. Fit new genuine OEM Cat belts. I agree with Nicky on this one. They are FAR better quality than anything available aftermarket. Once you have all that done then obtain an infra-red temperature gun and start taking some coolant temperature readings on the inlet/outlet tubes on the bottom tank of the radiator.
I’m starting to understand that perhaps the OP may not be able to justify the cost of all new pulleys to his boss,especially if they aren’t available as non oem parts. Fair enough,well here’s a compromise then for you. Buy brand new Cat fan belts. You could try the next thickness up and see how it performs. You also need a can of belt antislip with you and leave it with the driver, Open the governor to full and listen to the fan.It should give a fair old roar.Spray the belts and pulleys with the anti slip spray and see if the noise changes. These compromises will cost almost nothing.
I really can’t stress how much I agree with Nige,BCCcat at Hatchequip about the state of your pulleys and belts. They are worn out,and I’m surprised they don’t start spinning fan belts over and inside out! Many of my D8’s were of D8H,D8K vintage and suffered well worn out pulleys.I’ve tried to fight that battle over the years and always lost. New belts and pulleys have always solved the issue. Bear in mind that an old D8 can run happily on a reduced cooling system such as a choked dirty radiator,half choked coolers,rammed belly plates and tired transmission pumps simply because they were over engineered and built like ships.You could get away with half arsed maintenance and hitting things with a hammer. However,your D6R or T or whatever it is,will be engineered to a much finer degree and needs to be loved a lot more.There will be no overcapacity in the system at all.
Statements like this can only be made by someone that has learned this knowledge from decades of experience.
You know Shimmy……. Most of it was good luck and bull##it though
Zero pressure is brake fully on, you might need to explore more pressure checking when you sort out the cooling system drama.
I don't want to contradict all of you and your experience, but if the belts were slipping, it would be audible, since it is a large pulley and the belts would overheat. As for the large amount of dirt, yes, it is the dry season now, there is no rain and a lot of work, no time to clean. My problem is that I live and work on a tractor in the jungle, far from the city where I usually buy spare parts. Sometimes it is not possible to just call and buy, since you need to remove the working part, take it to the service center and then buy / order a new one. All this takes time. I will try to find or solve the problem with all the pulleys.
The belts may not be slipping to the extent that it is audible, but they will be slipping somewhat. Additionally because of the worn pulleys the belts will run lower in the pulley grooves and that will cause the fan to turn slower. The combination of the two factors could easily result in a loss of fan speed of 10% or maybe more. But right now with the overheating problem surely the machine can't work.? I do sympathise with the challenges facing you in respect of parts and quality of mechanics. Remember I worked in your area at one time.
If you need any help with Part Numbers to assist you in your searches for parts then please supply a complete machine Serial Number.
What about the intercooler? Is it clean inside, are there any damaged pipes? Is the turbocharger working properly? The correct operation of these components also greatly affects the engine temperature.
can work for 2 hours, then it starts to overheat, the oil and water temperature is close to the red zone
Well then, as long as whomever owns the machine, which must be invaluable there, realizes what kind of gamble is taking place and that ultimately, you are decreasing engine life, every time it hits the red zone, soldier on! What hasn’t been mentioned, is the excess heat being generated by the worn pulley and the worn belts riding so low in the sheave. I have changed thousands of belts and hundreds of sheaves and one thing I learned early on, is how damn hot a belt and wore out sheave is to change after running vs a good sheave and a good belt. I’m talking about 50 degrees difference. Like one you have to wear a pair of gloves and the other is cool to the touch. All that heat, gets transferred to the shaft and the engine or motor.
When these temperatures are reached, I turn off the engine. intercooler and turbocharger should be ok. air loss is excluded.
Really you should not do that because the heat will be retained at certain critical areas within the engine and it could lead to bigger (and more expensive) problems than you have right now. Instead I would suggest that you keep the engine running at about 1000 RPM with the transmission in neutral to facilitate the transfer of heat to the radiator. A comment is that you can gain a very good indication of the efficiency of the radiator by observing how fast the temperature gauges fall after the transmission is put into neutral.
Hi. I found these numbers for parts. But Avspare says that there are other numbers, please correct which numbers are relevant. crankshaft pulley 215-3363 / 215-3629? / 215-3673? pulley fan 185-0837 or 243-6491? TIGHTENING pulley 215-3291 belt set 2 * 7M-0185 Gracias.
You’ve accepted that the radiator core is full of dirt then. Well,that’s a start in the right direction. Do you have a portable jet wash that can draw water from puddles or a lake? If not,can you take 45g drum of water out to the machine?
Another question that you haven't been asked yet. Have you changed the fuel injectors, and if so, what part numbers did you use?
I’ve had that portable jet washer 35 years now and it’s been cleaning all my dozer radiators from D5 to D9. It needs only one man to lift it into a service vehicle and will run off any source of water. I’ll admit to damaging the water pumps on it over the years with dirty water, but I’ve replaced those 3 times in that time,but the benefits of keeping the machines running much cooler is the difference between bankruptcy and success.
The two attachments are what the system came up with for your specific machine Serial Number. Note that the 168-8383 Pulley Gp only applies for machines with S/N up to BRJ00128, but that does include your machine S/N. The crankshaft pulley is shown as 571-1553 but that is a new number for what was previously 215-3363. Either one would work. Fan pulley is shown as 185-0837. The 243-6491 Part Number is for machines with Serial Numbers from BRJ00129-Up. The correct belt set for your tractor is 221-7007. The 7M-0185 Part Number that you found is appropriate for an older model of machine but not yours. It is almost 20mm shorter in length and I think that would cause you major problems when attempting to install it.
yes, i have. only i have a lot of dust and i can wash the radiator every day, but every day it will get dirty again. because of the lack of rain, the ground becomes dusty. I clean it once a week.
I don't even know what number it is, how can I check? I recently changed one injector because it leaked 10 liters of diesel into the oil. I noticed because the oil level rose.
Some people will blow them out daily just with a leaf blower, then wash them every so often. A decent (60-130 cfm) air compressor is better but I realise they are expensive and not everyone has access to one.
I realize operating in dusty and dry conditions can be challenging but if you know you’re going to be operating in these conditions, preparations should be made to properly maintain the equipment. If that means quitting an hour early to wash out the radiators and coolers every day and cleaning the pre-filters, then that is what MUST be done. If not, you won’t be operating a barber chair, for long. Working with concrete dust and millings is one of the dustiest conditions I have been in but we were expected to maintain the equipment to run again in the morning. For 5+ years, I operated road reclamation equipment, the clean up and welding new carbide bases and whatever else the machines needed, were part of the job. As much as putting fuel in and greasing. Explaining to the boss and owner, why a machine wasn’t ready to run the next day, wasn’t fun.
When stripping summer topsoil with motor scrapers and D9’s pushing,the air filters and radiators would be blown out with air every tea break,so 3 times a day. On landfill sites,we have a compressor permanently left on the fill area for the compactors/traxcavators and dozers to use as many times a day as needed. As for jet washing,I would tend to do it at night time in order to give the water plenty of time to completely dry. There’s nothing worse than washing a machine out,then putting it straight back to work in the dust. Causes and blockages to set like concrete.
Do you not have a factura from whoever supplied the replacement injector quoting a Part Number.?
Yes, this is almost a new dozer, its condition is like 9 out of 10. I cut down trees and rake them into piles, i do land clearing. because of this, there can be different working conditions. this is what my tractor looks like. no, there is no part number on the invoice. there are many aftermarket injectors, non-oem, so they don't know which number is correct. i think 1725780
172-5780 is the correct fuel injector Part Number for your engine. Whether that is actually what you have in the engine is anyone's guess.
I do not think I have read anything more British then that.
I remember having this conversation with Scrubpuller one time. I have always had the same opinion as you and would never wash a tractor and put it back to work. He said they did it routinely with their D9s and HD21s. Bring them in and wash them hot and that big fan would have everything dry within a couple of minutes.
Our F150 was used on the Calgary ring road build….all filters clogged with hardened concrete dust. Including cabin filter….it was a cold drive home from Edmonton (Ritchie bros) at -25c (lol)!
Yes RC,we tend to drink tea over here old chap,and it goes down jolly well during the day,then it’s tally ho and off to the pub at night for a few pints of Boddingtins best bitter
@dimi - in a conversation with a member from Australia he reminded me of a communication we had over 2 years ago regarding his D6R that was found to have a problem in the bottom radiator tank (see Post #18 on Page 1) but also how he got the information regarding the problem. I have attached his message below. Thanks @Slicksta This confirms that there is previous history of coolant bypassing in the bottom radiator tank of D6R tractors. An infra-red heat gun should confirm this. “So, here's where I'm at with my climbing temp problem. All that I replaced and worked on made a positive difference, but not for long. Upon another laser heat check I found the temp across the radiators were all over the place this time, some with not much difference at all. Thought maybe the pump impellers were worn and not doing their job, so yeah, I replaced the good pump with a new one.............. then whilst inspecting the next 20km job for the power line company, we got talking about the problem I was having, and he told me of someone I knew in the area that had the same problem and what he found. He got him on the phone, and we discussed it, he told me that a family I also know of, that have a number of Dozers and one the exact same model as ours, had the same problem, and both his and theirs were found to have a hole in the bottom radiator tank, allowing the water on the intake to circulate around into the exit side without passing up and over the cores for cooling.”
Nige,that’s a priceless bit of information you’ve retrieved from the grey cells. That’s experience. I think you should buy yourself a beer.
Sometimes I even amaze myself….
Here's another comment from the same person, this time in regard to the difference in performance of aftermarket radiator cores compared to the OEM ones. This was AFTER he had fixed the bottom radiator tank issue. "On the hottest of days, working hard, the coolant temp went up near 95*c often, i'd pull up and it'd drop back to safe. I removed the three aftermarket cores (after thermal imaging them again) and replaced them with genuine [OEM] aluminium cores to match the others, and in the middle of summer on the hottest days now, it rarely goes above 84*c." Maybe it will require a thermal imaging camera to show differences in behaviour between individual radiator cores rather than the infra-red temp gun I mentioned earlier.
I knew a good field mechanic that told the same story of a plate in the bottom of the rad that was allowing the coolant to by-pass without going through the cores. He had figured it out with a heat gun as well. Simon C
Yes Nige, there was a huge difference to see the thermal imagining compared to my infra-red temp seeking gun. I had a well-respected mechanic from WesTrac (after many years, is no longer with them) chasing a break in wiring for me, I mentioned the heating problem and he put his thermal imaging screen (about the size of an iPad) to the cores, it showed what I was measuring, but...., I could see every inch of the cores, three at a time and it revealed what I wasn't seeing with the infra-red. The heat problem started one summer, and I went at everything, doing the simplest first, belt tension, loosening of the belts to check for drag on the fan bearing. Changed the good thermostat, bearings in the belt idler, even replaced a good water pump. No water in the oil, no oil in the water. Put a new lower radiator hose with a new anti-suction spring on, I went as far as locating a pressure gauge on the lift cylinder caps, with a hose connecting it to the overflow tube at the radiator cap, so I could see it while operating, to see if the cap was letting pressure go, put foam strips in every gap around the cores so no cooling was lost. I got talking to another owner of the same dozer as mine, he told me of the lower radiator tank issue. I removed it and did a flow check with the hose, water was passing through the separation wall and letting water flow into the return side so much that it wasn't overflowing out the top holes the cores sit on, not letting it do the two-pass run. I had the same fabricator up in Dalby do mine, everything including the weep hole, "he's done a few" (doing the weep hole was my doing) It 'significantly' improved the problem. BACK TO THE THERMAL IMAGING. It showed that the four aftermarket cores I put in place to save $ was the significant issue. One of them was slowing the water down so much it was almost fully blocked. I did a return to sender (that wasn't easy) and the salesman told me they'd had a few owners do the same (***). I replaced them with genuine aluminium cores, one of which is less fins per square inch than the other five, deliberately, so as to first-hand compare the difference in temp at the top of the cores. The welding up of the lower tank made such a difference it convinced me it was the issue, it WAS an issue, but it wasn't alone. I have in place now on the right-side pillar at the dash, both an oil and water mechanical temp gauges, to see exactly where they are at. I still have in place an aluminium overflow tank of the radiator, that's not needed. I have photos of everything connected to this dilemma, and a video of the lower tank water bypassing. NOW, it's one cool running C9 Acert.
Exact same story a guy I formerly worked with found, and solved. They had spent tons of money and time till he thermal image tested it. Just out of curiosity what brand of thermal image gun did you use. Thanks for sharing the whole story. Simon
I'm in the attempt to find out what the screen was, it belonged to the CAT dealership he was with for many years, in his support truck.