First off this is my first post here and I’m sure there will be more to come. I’m looking forward to picking up some knowledge from some of you seasoned owners, operators and mechanics. I don’t have much experience other than a general mechanical background but I have been studying the shop manuals on this thing. I recently bought a 1978 Cat D4E. Good running machine and everything seems to work fine. When I first looked at it the machine had sat about 10 years. Prior to that it had the powershift transmission rebuilt. When I inspected the fluids the trans oil looked milky with a touch of green color. I was told it was most likely condensation and could cook out. All other fluids looked good including coolant. I haven’t put too many hours on it but it looks the same. Thinking about changing the fluid and filter or at least the filter but thought it may be a cooler issue. I don’t fully understand the system so thought I could pass it on to this place. Thanks in advance for any and all reply’s. Might be able to get some pictures of the dipstick tomorrow.
I would replace the oil, filter, clean the magnetic and replace the cooler and go from there. 10 years? I would service all the compartments and all the filters and whatever Cat mentions in the O&M for a 2000 hr service.
Take an oil sample and find out if there's coolant in the tranny fluid. If not, change the fluid, filters and clean the screen and move on. If coolant is found in the sample, rebuild the cooler. Hard to believe someone would rebuild a transmission and wouldn't rebuild the cooler at the same time but it happens.
I’ve been trying to tackle one issue at a time on this thing since I’ve got it. It sounds like the oil sample would be the best option unless the green color would be a dead giveaway. I would hate to change fluid and filters only to have to repeat the process.
Well this is what the dipstick shows. I’m going to see about a fluid analysis tomorrow.
You don't need to waste your money getting that analyzed. It's obvious something is wrong with it. As Coaldust suggested, drain the oil, remove and clean the magnetic screen, and take photos of whatever you find for posterity. The fluid needs to be at normal operating temperature before you drain it. What do you have in the way of manuals.? You will need at least an Operation & Maintenance Manual and probably a Parts Manual. The need for a Service Manual would depend on how much of your own repairs you intend doing along with your mechanical capability.
I have a parts manual and I believe 2 different service manuals. I plan to do as much repairs as I can, however I don’t plan to tear into something I don’t feel confident in doing. Is there a way to warm up the transmission without working the dozer or do I need to operate it til the torque converter shows warm then drain?
You can warm up the machine without moving it by placing the transmission in 3rd speed and stalling the converter against the service brake at a medium engine RPM. Should only take a few minutes to warm it up from stone cold.
So I warmed up the tractor and located the drain plug. Got the fluid out of the transmission. I wasn’t prepared for the rush of a 2” diameter drain plug but it is drained. Wow, what a mess. The magnet didn’t have anything large stuck to it. Mostly fine particles. I suppose normal. Next is to pull the filter and drop the belly pan for the screen cleaning. I’m going to support it with a jack, I’m sure it’s very heavy. The fluid looks terrible and I’m guessing it has to be antifreeze contamination. Is there a way to flush the system? Here’s more pictures of the fluid and what I got off the magnet.
I got the belly pan dropped safely and found the magnetic screen. It did have some debris... small trash, a pine needle, very little bit of small metal and mostly rubber. Small rubber chunks and pieces maybe 1/8”. I ran a magnet over the pile to determine what was what. The canister filter was relatively clean besides the contaminated oil. Green oil everywhere. I suppose the obvious culprit would be the trans cooler but I’m only giving an educated guess. My coolant doesn’t look to have oil In it. Would rebuilding the cooler be an option or buy new?
Remove and pressure test the cooler to determine if it is leaking might be an appropriate next step.
That’s nasty. Good decision to address it now, instead of running it.
Is it necessary to drain the engine oil to change the cooler? The coolant would have to be drained but I wasn’t sure about the oil.
No, you don’t have to drop the engine oil.
How about you just pressurize the radiator and see if you have a coolant leak? If you do take the bottom transmission oil line off the oil cooler to see if it's leaking? Bob
I suppose there’s more than one way to skin a Cat... I was kinda tied up today so it wasn’t possible to do much of anything. With this level of contamination I couldn’t imagine how else it would be in this condition without a cooler leak. But I’ve been wrong before. I figured I would be taking it off one way or another anyways. Besides the maintenance schedule calls for coolant change as well... Might as well drop the front pan and clean it out while I’m at it.
Have you had to add coolant to your radiator? Bob
I dont know how safe it is for a Powershift transmission, but older manuals would suggest using kerosene or diesel to wash transmissions and final drives.
I haven’t had to add much coolant but I have added some. When I first bought it we added about 1.5 gallons to get it up to the neck. If there’s a leak it isn’t much. The previous owner acted like no matter what I did the fluid would look like that, which it would if it continued to get coolant leaked in. I’m not quite to where I would flush it out but I’m all ears on the subject. At worse I would put oil in and new filter, run it for several hours then change fluid and filter. I would rather not waste expensive oil like that but somehow it needs rinsed without taking a risk on further contamination. I’m about to drain the coolant and pull the trans cooler off to be pressure tested. Thanks for all the input, greatly appreciated!
Replace the cooler. The cost of oil alone warrants it. I have had a number of those coolers let water into the oil rather than the other way round, which would seem more logical. Have battled to find leaks using air to pressure test, yet when they are hot the crack obviously expands enough to allow leakage. As far as I know there are two different coolers depending on serial number. https://www.ebay.com/itm/7N0128-9M8...D-D4E-D5-D5B-D5H-D6C-D6D-/231488723092?_ul=IN https://www.ebay.com/itm/6N9851-OIL...413-5S3414-0R5515-2Y2070-2Y5229-/291631281371
Not unknown for a cooler to only leak when it gets hot despite testing OK when cold.
Sitting outside neglected for ten years. There is a chance the coolant mixture was weak and there was some freeze damage at some point.
Yeah everything said is making sense. The coolant looked fine but when I removed the cooler there was signs of corrosion (mild) on the core, from what I could see of it. Cat wants $757 plus a $297 core for a reman or $522 for a yellow mark. I’d much rather get an aftermarket but I’d hate to order the wrong one. Glum is right my parts manual shows 2 coolers but I’m unsure how to tell which I have. Serial# 69x 0721 arrangement# 3A 5092 Incase anyone is handy with sorting these numbers out. I drove in to town to try to source all my fluids and filters I will need and order new gaskets. Any input on coolant choice and strength? I do have an aftermarket supplier I can call and check his prices but I doubt he will beat the eBay cooler.
That should use 7N0128 if nothing has been modified. Quick check is does each pipe mounting to the cooler use 2 bolts or four. Earlier smaller cooler, 7N0128 had 2 bolts on each flange. Later larger 6N9851 has for bolts per flange.
Each pipe has 2 bolts per flange. Somehow I didn’t notice the other had 4. It does look like the 7N 0128
7N-1028 cooler core with 2-bolt fixings on the lines was used up to machine Serial Number 69X1531. 6N-9851 cooler core with 4-bolt fixings was used from machine Serial number 69X1532-Up 7N-1028 on the left 6N-9851 on the right.
Costex (ebay seller) used to make good stuff but at $140 I'd wonder if that cooler was now made in China. You might want to call American Crane & Tractor and ask if CGR makes a cooler. If they sell an Italian (CGR) cooler for around $300, I'd go for it. The CAT reman cooler is likely China, as is the aftermarket one they're selling. For that kind of money, I'd keep looking.
I got the new transmission cooler installed. New fluid and antifreeze. Everything seems to work as usual with no leaks so far. I did get my trans fluid a little above the full mark. Almost a half inch when warm in park and running. Should I be concerned with running it or see if I can get some out? The fluid looks pretty good but maybe a bit of the older oil remnants made it have a slight haze but nothing like it was. One last thing. Could start another thread if suggested. Every once in a while during shifts it will act like it hits neutral. Select next higher gear and still the same. Back to neutral and then to the desired gear and it works every time. Doesn’t do it every time but it will in either forward and reverse. Don’t know if it’s an adjustment issue, quirk of the transmission or a problem. Thanks again for all the help, hopefully it will help someone else. Haven’t found a whole lot of info on these dozers so maybe that means they are good ones. So far I like it but it has a few things to iron out.