hello, so i have a super nice and tight d6d. everything works lovely. it sat a few years due to economic decline. i got it ready for a job, new fluids, new batteries, new roller, this and that.... i put in to-4 30 weight trans hyd fluid in the transmission. and new filters due to it sitting and i was seeing a slight milky texture in trans. i assumed it was condensation from sitting. so i a running this machine and it is working lovely. nothing is heating up. flawless. i check the tranny fluid....it seems to have a milky texture still. what could cause this? how does the trans cooler work in relationship to the radiator? can coolant be getting in a cracked tube in cooler and entering the trans fluid? how is the trans cooling system laid out in this machine? does anyone have a page to view from the service manual? any ideas? thanks!
Check the coolant in the radiator , is it clear / clean ? Don't know about the D 6 but my IH td25 dozer uses what I call a cartridge type transmission cooler . Cooler is bolted to the side of the engine & ties in to the cooling system . Couple hydraulic lines bring the oil from the transmission . Anyhow , I fired it up one morning and while letting it warm up I noticed coolant coming out the overflow tube . Shut the engine down & pulled the radiator cap ....... Instant milk shake in the radiator tank . Pulled the cooler & put about 25 psi air on the oil side found one ruptured tube , soldered it up & was back in action .
The trans cooler can leak coolant into the trans but you should be having to add coolant if it is. If you had moisture in the trans from sitting or condensation you would not get it all out by a single oil change. There is a lot of oil that remains in the system when you drain it. I guess the question is are you loosing coolant? If it is coolant in the oil if you leave it parked without running for a couple days you might be able to crack the trans drain plug loose and back it out until it starts dripping . If it drips clear water it's a condensation issue. If it drips green coolant you know what's happening.
milky you could be right. when i changed the filter up beside the engine, there was some milky oil still under filter. i am sure the lines still had milky fluid. i didnt even get to pour 25 gallons in the dozer that i should hold after completely draining the trans. so the trans cooler does have coolant passing by it? it is a white milky. not a green coolant milky. i havent lost any coolant that i can see. coolant looks green but i will recheck. so the water will separate to the bottom of trans and i can let that drip out after sitting. hmmm... is it normal for one that has sat a year to get condensation in it? thanks!
Not that much water. There's thousands of old tractors that haven't been run or had a fluid change in years/decades, they don't turn milky unless rainwater is getting in. You might have been able to get some water to drain out at first, then run it to stir up the fluid and see if you get any more out after it sits. The other possibility is the oil is getting aerated. Drip some on a hot piece of steel, it will sizzle if there's water in it, and just smoke like clean oil if there's air in it.
aerated thanks. the oil does seem foamy. i am pretty sure i did not get all the moisture out of the lines when i did the fluid change. what would be causing the aeration you think? is that bad? it shifts and runs flawlessly.
Aeration is usually caused by an air leak in the suction side of the system, often an old o-ring in a joint somewhere that's dried up and cracked.
It is usually the oil that travels into the radiator not vise versa from any failed cooler. The oil pressure from a trans or an engine will overcome any pressure created in a cooling system. Have you run the machine hard to really heat the trans up since the change ? You may evaporate some off with a good run.
A cooler leak will pass oil into the radiator when the machine is running, and if the machine is stopped hot the pressure in the cooling system will push a certain amount of coolant into the oil until the pressure in the cooling system drops to zero.
With trans cooler leaks I find you get more coolant in the oil then oil in the coolant because the trans oil cooler only has trans lube pressure on it which can be under 10 psi. An engine oil cooler runs higher pressure on the oil side and will push oil into the rad. If it's water rather than coolant in the trans it is probably from rain entering rather then just condensation. If the top steering clutch covers have any leaks and water is allowed to sit on top of the case it will leak into the trans.
Aeration or rainwater maybe Thanks for the help so far guys. Dang. It is possible that rainwater is getting around the steering clutch covers. I'm thinking I didn't get all the milky oil out when I changed it cause the lines and such took up most of the 4 gallons that it didn't need after draining it and replacing it. It is supposed to hold 25 gallons and it only held like 20 or 21 ish . I drained it from the big plug under the tranny. We had the transmission totally rebuilt 500-1000 hours ago. So if it's aerating from the suction side....how in the world do I trace that down? Oh lord, I need a service manual at a good deal.
Does this machine have a winch? If so drain the fluid out of it. They always leak rain water in which fills it up and the water displaces the oil into the transmission until the water is all that's left. It then also fills the transmission.
No winch Hey. This Dozer does not have a winch. It has rippers. But I understand what you are saying. I think d6c had a big issue with that right? If this is caused by aeration... Will it hurt it to just leave it alone? How do I find the leak? If it's caused by the cooler... Oh lord. Rainwater? Well damn...... Off with the seat and toolboxes and floorboard and fuel tank right?
If it is a rainwater leak you can maybe see it from the back looking under the fuel tank or from under the seat. Look for any broken or missing bolts on top of the case anywhere. Check the breathers are there and not broken. There should be one screwed into the clutch covers.
Start by eliminating the easier possibilities first. As Mobiltech says you can likely get a reasonable look at the clutch covers from behind the tractor. Each cover should have a breather in it and should have all the bolts in place and they should at least appear to be tight. If you have any doubt whatsoever then lift the floor plate, clean everything up, make sure the cover gaskets are in good condition, all bolts tight, and the breathers are clean. It's the only way to eliminate the possibility. If you do end up lifting the floor plate and find it is NOT the clutch covers then DON'T PUT IT BACK until you have completed Step 2 below because you will need the same floor plate up for that. Second possibility would be an air leak in the suction side of the oil system, often caused by an old dried-up O-ring in a flange somewhere. There are not many joints that can leak up to and including the pump from where the oil is sucked out of the transmission case. If you definitively eliminate water entry via the clutch covers then post back here and I'll post a schematic of the transmission hydraulic system showing all the joints to check, speaking from memory I think it will be only 2 or 3.
Would an oil analysis tell if it was air, rain water, or cooling water? That may eliminate many possibilities. May also tell if other damage has started.
An oil analysis might detect the presence of glycol if it was a cooler failure. If the coolant in the radiator is of very low strength the analysis probably won't pick up glycol, but it might pick up either sodium or potassium, both of which are additives in antifreeze/coolant. Not any lead-tin faced bearings in a transmission for the coolant to get at thought, not like an engine ............
Thanks guys. So what is the best process for doing an oil analysis? I haven't performed one in a few years due to economic downturn in economy in the southeast USA. I used to have this brass looking thing with a black pull handle for an oil sample. Just put a hose down in the fill tube and pull some fluid and put in a little plastic white bottle? Write my inquiry on the card and mail to CAT Oil analysis??? Any idea of cost? If this is an aeration problem...do i NEED to fix it? does it cause harm? IF I need to fix it...how do I pinpoint an aeration cause and leak detection in a line? Smoke? lol. Thanks Nige and ole-iron-habit etc.... Much appreciated!
Buy the kit at Cat, $11 each or $100 something for a ten pack that includes the tubing. That includes postage and testing! You want to either drain the oil from a line while it's running, or suck it directly into the bottle with a clean piece of tubing (your vacuum pump and oil suction hose both go into the bottle so you don't contaminate the oil with your pump or old tubing). I mentioned aeration because "milky" is hard to define, you might be able to tell by looking at it whether it's water or air, or try the drip on a hot manifold test, or put a quart in a glass jar and let it sit overnight, or... If it's aeration it will cause problems EVENTUALLY, a little bit of air is normal, a little water makes the oil's antifoaming additives less effective. Maybe you could use it to see what happens, hopefully you have a transmission pressure and temp gauges that work?
i am pretty sure the coolant is getting in oil now. overflowing dipstick on occasion. thanks for the info about the oil sample. i may do that at a later time. so, the coolant is getting low and the trans fluid is belching out the dipstick sometimes and running down the side. milky. i am pretty sure its the trans cooler. i dont have a service manual. so how is this machine laid out? the trans cooler is built into the radiator? how much to buy a new or should i get it repaired (brazed?). Do i take the sweeps off the machine...pulls the hardnose around the radiator and the pull the radiator? is this thing built INTO the radiator or connects to it? the fins on my radiator have lots of flattening that i have noticed? any good ideas and tips? time? money? a good source for a cooler or radiator with cooler? price? thanks guys
I don't know how big this radiator is, but I've had good luck picking the gunk out, and straightening the fins with a little pick, like an o-ring hook set. You can use a fin comb (HVAC tool) but the pick is nearly as fast. The comb will hang up more, and isn't as good at pulling out gunk. Wash it down with a hose, use some Dawn dish soap, blow it out with air, clean it out with a pick or comb, wash and blow. You can make a big difference in an hour or two.
fin straigtening on radiator thank you sir. good idea. i have done this before as well. i think i will do that. you know fins get bumped so easily when working on these tractors! now i am in the pursuit of the transmission oil cooler issue. i may need to make a new thread. i have never installed a trans oil cooler on this dozer so i need to trace it down, where is it located on machine, how to access and remove it, and how much it costs and a good source for the part! any ideas?
I suggest to stick with this thread. After all it's the same failure related to the original symptoms you posted. I'm sure one of our resident experts on this generation of tractor will be along shortly to give you a complete "how to" procedure for replacing the cooler.
Thank you NIGE. So, here in Georgia...it was past closing time for my nearest CAT dealer and so i called the west coast HOLT CAT to get a price on the trans oil cooler. 3 hours behind east coast time....lol. Very nice parts guy. My machine is: Caterpillar D6D serial# 04x07840 transmission #2ha03884 mid 1980's to later machine. the part # for the trans oil cooler is # 0r3508 price: $1111.00 for part. not including o-rings and gaskets etc.... and the core is an additional $430.00. SO, what determines if my core is good or bad? also, is the manufacturer of an aftermarket trans oil cooler from a supplier just as quality as the Cat brand part? Sometimes...it is the same factory making both. Sometimes not..... The parts guys just said it was a CAT part..wasnt able to offer me classic part or premium cat. any ideas on where i might get a cooler other than cat? is there a quality difference and if so what? kinda seems to me that these things could be less critical than engine bearing and under carriage but idk.... either it works or doesnt..and either it cools effectively or doesnt.....idk? the parts guy said he felt like this cooler was under the floorboard and stood straight up and down in a canister like fashion. i called my heavyquip parts guy and he is off duty until monday. i would love to find this part at a good deal tommorow or saturday and work on this thing all weekend and have it ready for monday work! but dang...i gotta buy 25 gallons of TO-4 30 weight fluid again! And heck....did the stuff get in my coolant? i cant see cause the coolant is low. well gosh...gotta buy the dang coolant too? if so...what grade of coolant do i need to look for at my local napa? what mix do i need? average price to expect? thanks guys! i love this site...
Part Number of cooler core seems to be correct - 0R-3508. There is also a Classic Part 383-3699 listed for that same cooler. The Classic Part is direct sale (no Core Charge like Reman) and is listed in my book at $582. The Core Charge is what you get back when you turn in your old cooler in exchange for the Reman one. AFAIK for a cooler of this type the obtain full Core Credit the cooler must be undamaged externally and have no previous internal repairs - You know like sometimes a radiator repair shop will solder up both ends of a radiator tube that's leaking to keep it working. I will find the definitive answer and post the info back here. You will have to drain both cooling system and transmission oil lines to change the cooler, plus you will need to change the transmission oil filter. If you want the Service Manual procedure to replace the cooler PM me your e-mail address. From what I see the cooler is right next to the transmission oil filter. Coolant - look for a "Heavy Duty pre-mixed Coolant" that meets ASTM Spec. D6210 or D4985.
If you're sitting in the seat the cooler is on the left side of the engine. It stands upright and is mounted to an elbow off the end of the engine oil cooler. There are two trans lines to come off the backside. There are 4 bolts on top holding it to the elbow. There will be another bracket on the bottom attaching it to the oil pan bolts. Drain the coolant first. Aftermarket cooler should be a fair bit cheaper and they seem to last ok. Depends on how many hours you want to get out of the machine yet.
more thanks so much NIGE and Mobiltech etc.... I found an oil cooler on ebay. it is eBay item number: 230404579509 http://www.ebay.com/itm/230404579509?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 priced @ $454.60 plus some shipping. What i wonder is.....is the classic cooler from cat the same as other aftermarket coolers? their cant be 10 different factories trying to make this cooler. it has to coming from the same source somewhere right? and, if the aftermarket/classic cooler requires no core...does this mean it isnt rebuilt but is NEW? Why is the CAT cooler requiring a core...plus its rebuilt...and is money? seems like a new one would be a better bet than a rebuilt one? i am sensing that someone might say...."well...the cat cooler is rebuilt and rebuildable and is heavier duty and lasts longer and has better brass or metal etc...." but the size of this cant allow for a part to be that much thicker or heavier duty can it? now i am well aware...that cat undercarriage is better steel and lasts longer than aftermarket chinese undercarriage. but on an oil cooler such as this...what are the comparisons? i am looking at saving half the price here? and....is a used cooler worth it? thanks so much.
Pull your cooler and take it to a heavy radiator shop and have them check it.You may only have leaker gaskets. Bob
I think the aftermarket ones are new coolers. Classic quality is hit and miss sometimes I wonder if cat doesn't sell the cheapest poorest quality classic parts to scare you back to buying only cat genuine parts. If it's not a high use machine I wouldn't be afraid of the eBay cooler.
And flush your cooling system before refilling with expensive coolant.
costex cooler or cat classic or cat expensive and flush.... What do you feel is the best way to flush the coolant on the d6d dozer? water? an additive? prestone additive? waterhose and run it then drain over and over??? i found a cooler from costex......or a cat classic...or the ultra expensive cat unit. hmmm. the costex supplied dealers say they never had any comebacks that they can recall.....? thanks
The best way to flush a cooling system is to put water in it and add some non-foaming dishwasher soap like Cascade. Run the machine up to operating temperature and leave it idling for about 10 minutes for the soap to penetrate. Drain, refill with clean water, and run again for a couple of minutes. Repeat step 2 if necessary until the water coming out is clean. Then fill the system with coolant.
^^^ This .
MHO, as already posted, remove the oilcooler and pressure check it, or take to a radiator shop and let them do it before spending $500 plus!. Also you need to drain the torque converter housing as well as the tranny, and pull the suction screen, if you did not do this the last time that's where your 4 gallons of oil was that you did not get out the last time. I have drained many trans. and engines over the years from water contamination and have never got all the water out in one drain, it may take 4-5 drains to get it all out, a warm tranny is your friend here and will evaporate a good share in time but I would drain it more than once. Oil is cheaper than a trans. Lee
Thanks guys! So, I was thinking the cooler for my machine was gonna be under the floor board, but from seeing a few schematics, it must behind the engine oil cooler on the side of the engine block huh? I am having a hard time locating the cooler over the weekend. I have to wait till tommorrow MONDAY. I can get the aftermarket from a typical costex supplied place, or a cat classic, or a genuine cat with a core charge. Either way...i have to order the dang thing and wait.... So, in my area,,,i can't think of a radiator shop that can test a cooler such as this. Atlanta, Chattanooga, or Asheville or Knoxville are all 2 hours away in every direction. I don't mind making the trip if they can test it while I am there. I may actually just buy a cooler and have my old one fixed if it is fixable. For a spare. Anyone know of a radiator shop in these areas that can quickly test this thing? What are the guts of the cooler made of? Brass? So they just go inside and weld up the tube? Idk.... So i will drain the torque converter....and the screen under the center bottom of the machine. then back up to the trans plug and drain it...then drain the engine coolant from the bottom of the radiator right? as far as the trans screen...i have and usually do check and clean the magnets and surrounding screen often. i hope there isnt a torque convertor housing belly pan that weighs a ton....ugh.... this dozer has been great and works well. ive been easy on it. i put HD CAT undercarriage on it years ago and its been great. the rails still look sweet! the grousers havent even been worn down. I did do a preventive bushing and pin turn on it a few years ago just to be safe. i just put an aftermarket bottom front roller put on it due to a failing roller. Georgia clay must be mild on the grousers. i am very careful not to spin the dozer and i feather the decelerator pedal always. i always make 3-4 point turns when turning. i rarely ever spin the dozer around. the multi point turn seems to really save undercarriage. i havent gotten to use this dozer in any large capacity in many years. just small jobs. all of the large jobs went away in the crash and actually a few years before the crash. i think the cooler must have failed to corrosion....i think it is probably the original cooler. i have never had to put one on this tractor. EVER. god, i dread buying the dang to-4 30 weight fluid. its very expensive. best deal i got was a napa brand fluid in 5 gallon buckets. i guess i will buy some form of heavy duty diesel rated coolant. i will also do the cascade detergent trick. i heard that the prestone flush stuff was very hard on coolers. thanks so much guys! thank god this dozer is a CAT. i would hate to be tracing down an oddball brand name dozer part.
bought it, installed it ok. update. so i bought the cat classic cooler. the price was very competitive with other aftermarket suppliers. i checked costex, heavyquip, iron peddlers, mosley etc...and cat classic was within range. with no core needed. but the more expensive cat cooler had a core. the thing is..the classic cooler came in a regular cat box and didnt say classic...pretty much looks factory. the oil is very expensive. even at a discount. to-4 30 weight hydro trans oil is expensive. but now...it is NOT milky!! the cooler happened to be on the oil filter side of engine. driver side if this was a usa car. hooked on behind the oil cooler. sandwiched with a top angle piece coming off oil cooler and a bottom cap piece. two hoses run from the trans fluid. hard to get off. the bolt that couple the housing against the engine oil cooler that is on the back engine block side is HARD to remove. and the one bolt underneath that stabilizes the weight of the cooler is pretty difficult. the engine side curtain had to be removed too. so i put in fresh water and coolant (just to be safe)...and baking soda to let it run a few days before the fush drain. my petcock had broken off and i had to thread the whole thing out to drain. i also did and oil change because the oil filter had to be removed anyways.... the machine isnt running in the red...but its warm in the green range on the gauges. my fins in the radiator needs to be combed. and i need to pressure wash the machine and radiator. i also need a few flushes. the belts are kind loose...need to adjust that. the oil cooler with gaskets and various doo dads was $850. the oil is 25 gallons x $75.00 per 5 gallon bucket. then tax. then i had my mechanic on call come help me install this. havent gotten the bill on that. so now...its fixed. i guess the trans cooler was an original unit. we have never replaced it until now! 7000 hours roughly. i guess i can now help others with this experience. its basically a huge huge oil cooler. 5 times bigger than the small one for the engine oil cooler. it sits up and down instead of side to side. thanks for the help guys. now to get the temps down..... more to be added later. i may upload some pics!