After about a year of refurbishing our D3 and dealing with myriad issues, we've finally began pushing the old girl into labor. My partner ran her for a few hours pushing dirt and manzanita to clear an area for sampling, with only a minor issue of the shuttle lever having problems when shifting from forward to reverse. About a week later I decided I would get some hands-on time by taking her up the hill and do some road grooming and brush clearing. Within the space of maybe 15 minutes three significant problems popped up almost simultaneously, to wit: 1) The right side yoke seal decided to disintegrate under my watchfull eyes, thus posing the risk of having the track part ways with the ider. 2) The motor began to smell hot-ish, which we hadn't had problems with before. 3) As I looked back to see if there was any sign of coolant leaks, I saw a large trail of hydraulic oil behind me. Things like this never happen to my partner, only me! We always carry radios, so I called down to him to advise I had loss of hydraulic blade and ripper control from loss of hydraulic fluid, as well as an overheating problem from loss of coolant. He came up to see for himself, and that's where he noticed the fresh grease coming out of the yoke seal, which we had just pumped up before I went up the hill. To shorten an already long story and get to the point, we replaced the badly pitted yoke and yoke seal, found the oil return line from the hydraulic pump worn through from abrasion with the skid plate, and relaced the water pump on the assumption that the seals were gone, even though there was no evidence of coolant coming out of the weep hole which is so common. After replacing the water pump, we were filling the radiator with fresh coolant when my partner noticed coolant pouring out from what seemed like the rear of the new pump. As we looked closer we could see that there is a space between the motor front cover (which is home for the water pump, governor, and other magical stuff), and the cylinder head. If the thermostat housing cover and the themostat is removed, you would see through the area behind the thermostat and directly into the front of the cylinder head. I assume there is a connecting pipe or short hose that provides a path for hot coolant to pass to the front cover and hit the hot end of the thermostat. In scraping away dirt and old grease we could see that a worm-gear hose clamp surrounds whatever the ~1" pipe or connection beween head and cover is. My best guess is that this was a "band-aid" fix to a prior leak. I haven't pulled the thermostat yet to confirm my suspicions, but would like to get an idea of what I'm looking at in that connection that spans about a 1" gap between head and cover. I couldn't find anything in the parts or service manual referrencing this area, so if any of you have had experience pulling the cover, servicing anything like this, please let me know. I sure as hell don't want to have to pull that cover if I can help it, and I have a couple of ideas on how to seal that area if need be. A picture of the cover from the parts manual is included, and the thermostat mounting area (see item #9) is at the top and just odd right center in the drawing. Thanks as always, -Tom
have you got the correct parts book for this ser engine if not, hit up Nige and he look up sis for you mine at work
You need a 1w4724 clamp, a 7n4636 seal and a 7n4637 ferrule. you loosen the old hose clamp and pull the old one out clean surfaces put ferrule in seal put hose clamp over it there is a little shelf on the head to locate seal make sure you can get at clamp to tighten It when it's in no cover removal needed
I can always depend on getting the right information when I need it on this forum. Thanks Mhave you got the correct parts book for this ser engine if not, hit up Nige and he look up sis for you mine at work
I got the manuals for our machine from Jen Sales, but there may be an earlier and later version. Since we have the 3204 motor I'd assume that the motor group would be the same. That I couldn't find reference to the crossover hose doesn't mean it's not there, but I tried several ways without success. But Pittsburgh Cat Man seems to have pulled us out of the clutch with part numbers and method. Thanks, -Tom
This help?
The only good thing you can say about their manuals is that they are better than the ones from Finney, which is not saying much...... To identify the correct Parts Manual is the Serial Number of your 79U-prefix tractor above or below 4708.? Here is a genuine OEM Service Manual for sale on eBay
That's the manual we got from JenSales, but couldn't find the ferrule, seal, and clamp location. Pittsburghcatman came through though. The clamp, seal, and ferrule are used on other Cat equipment and probably cheapest from Cat, which I will call in the morning. Thanks as always, Nige! -Tom
What is the Cat Publication reference on the Parts Manual you have.? The parts you needed (5, 6, & 7) all show up in what I can access.
For $250 they must be pretty proud of it! I've done well with JenSales manuals for our various equipment, no complaints. Thanks again! -tom
So your tractor has a Serial Number above 97U4709 and is fitted with an engine carrying a Serial Number above 45V17160.? Look for the 4N-0188 Water Lines Gp.
45V2208
I went back and searched through your posts for the S/N of the tractor. It is BELOW 79U4708. IMHO you have the wrong Parts Manual, or at the very least not the one that is appropriate for your machine Serial Number. According to the cover yours is for machines with S/N 79U4709-Up and fitted with engines from S/N 45V17160-up. See below. The correct Parts Manual for machines with S/N 79U1-4708 is Cat Publication reference UEG0652S. Here's one for $25 on eBay .
Hmmm see post 6 you need a engine book no engine in that parts book
My apologies. I missed that part, even though I looked at the image. For machine engines with Serial Numbers between 45V1-171159 you need UEG0678S. Also available on eBay . Either way the Parts Manual you have is not the correct one for your machine Serial Number.
When I got the manuals for this machine from JenSales, the later version was the only one available. As we were concerned mostly with rebuilding the 6-way blade and track adjusters, the manual served it's purpose. With the eBay leads you and Pittsburgh Cat Man provided, I've just now snagged both copies that each of you refferenced. The question now is, are the part numbers provided by PCM still good for our early motor?
Are the three part numbers you posted earlier still valid for the early 3204 motor? I snagged the eBay manual, and another arts book for the early number motor off eBay just now. Many thanks to you and nige for the help. -Tom
Yes they are. See attached. The only difference is that 1W-4724 is replaced by 2J-6540 but to all intents & purposes they are simply two versions of the same thing.
That is simply a common screw clamp, 2-3" span. The ferrule and seal were the critical elements, so I'll order tjem tomorrow from our local Cat dealer. Thanks for the research Nige! -Tom
So... the solution to the major water leak appears to be a failure of either the ferrule or the seal (unless the screw clamp failed!). I picked up the three items as suggested by pittsburghcatman above, which consist of the seal, ferrule, and the clamp. Though you could save acouple of bucks by getting a cheaper 2"-3" range screw clamp, I went with my CAT dealer cuz he's a good guy! The 1W-4724 clamp was $4.32, the 7N-4636 (rubber) seal was $8.49, and the 7N4637 (plastic) ferrule was $35.92. I was out the door for $52.96 with tax. After-market prices for the same part numbers were lower and higher, but the confidence in getting the right parts was more than worth it to me. This same arrangement for the 3204 Cat motor is used for most, if not all of the Cat machines using the same motor. So here are a couple of pictures to show the individual parts, and the assumed assembly. Looks like when the clamp is tightened, the rubber seal expands to close the gap between the motor's fron cover and the head to provide means of conveying hot head coolant into the hot side of the thermostat. This leak when it popped up defied normal explanation, but seeing how simple the fix is makews perfect sense. Hope this explainer helps others who experience the same issue. Best wishes to all! -Tom The three parts... How they are assembled between front cover and cylinder head (some kind of slippery stuff would be advised when installing!)
Be careful of the clamp some of the clamps are too wide at piece that holds the screw to tighten the clamp. had some trouble with some of the cat clamps years ago. also I don't recommend any slippery stuff it goes in pretty easy with clamp loose
I went with the Cat part figuring it was the right fit and sufficient heft, as opposed to cheap knock-offs. I'll know when we go back up after the storms pass through. And thanks for the tip to NOT USE slippery stuff! -Tom
I have same leak, taking you drained coolant low enough to loosen, pull it out , slip in new assembly, tighten and refill coolant?
Yes, and probably the easiest job repair you could ask for. You will see the screw clamp between the front cover and top of the cylinder head. A 5/16" nut driver or 1/4" drive socket on a short extension will give you access. Unscrew it all the way and remove. You should now be able to slip the ferrule and surrounding seal up and out. My original ferrule is brass and appears to still be in good condition. The new (and expensive!) ferrule is plastic. My failure was caused by a bad seal. I could have saved around $40 if I knew my old ferrule was still good. Install the new seal and ferrule the same way you took the old one out. Good luck! -Tom