'98 D5C Powershift, 9DL serial number. Transmission pump leaking anytime it is running, probably 15 to 20 drips a minute when hot. I pulled the pump and the main seal looks like it is fine and it isn't leaking between the pump and transmission (1st photo center left) when it was in operation. It seems to be leaking/puddling up on the top the pump housing (middle photo center) just below the part number then it runs down the side of the transmission. I didn't think it was a crack initially because of how straight/machined that line looks but now I'm not sure. I haven't pulled the pump out of the housing yet because I wasn't sure how hard it would be to put back in (I do have the service manual btw). I'll call my local CAT folks this week but wanted to see what thoughts you might have. 1 - Has anyone had this issue and what was the fix? A quick search online for that part number came up blank and before I get into a long search, I'd like to get some input on what I'm dealing with. 2 - Anyone welded / used some cold weld product with any success on something like this? Thanks in advance. I wasn't able to find anything when I did a search of the archives. John
That is a very odd crack. Welding would be difficult. Not impossible but the whole casting would have to come out for the best repair. The crack would have to be Vee'd out and super clean. The hardest part is getting all the oil out of the crack. If the issue is mostly oil leaking you might be able to Vee out the crack some, burn any oil out with a torch and use a good epoxy. Getting it clean enough for epoxy is easier than for welding because there isn't the intense heat of welding that would draw oil out. If it were some type of cast steel, welding would be much easier. Brazing is another option if it is cast iron but requires it to come out and needs lots and lots of heat. You might try cleaning it and welding it cold (short welds about an inch long and peening while hot with a needle scaler or dull chipping hammer) with nickel rods but that may lead to more cracking and/or a porous weld that would still leak. A specialty rod supplier like Castolin Eutectic likely has a welding procedure and the proper rods to use.
1. Nothing surprises me any more. IMO the fix is a replacement pump body as a minimum. Considering the tight tolerances to which the internal parts of the pump turn I would not want to risk distortion of the pump body causing any binding of the internal parts and the chance of a pump seizure which could contaminate the whole system. 2. No comment. See attached which is the complete parts breakdown of the pump and its mounting. You may find it cheaper to look for a complete pump rather than just a replacement pump body which may be something akin to unobtainium.
Ditto
Looks like the pump is built in sections and it separates there. Probably just needs seals. Aww scratch that. I was looking at the wrong crack!
That's because 9P9472 is the Part Number of the casting from which the pump body 9P9471 is manufactured.
No, you are absolutely correct. Once I got it off the dozer and cleaned up (and slept on it) I realized it definitely is in sections. There were 4 internal bolts holding the two sections together. Took them out, the sections came apart exposing the seal. When I was taking the seal out it fell apart in 6 pieces so I'm going to assume that was the issue. Hope to get it back together soon and see how it goes.
I was hoping to not have to go that route but luckily I think I was just being dense and was able to get the pump house separated from the "mounting flange". There was a seal between the two that was in bad shape. Hopefully that fixes my issue.
Thanks for the reply. Turns out, that long straight 'crack' is where the pump housing and 'flange' come together and I was able to get them separated exposing a seal. Once I get that replaced, I'm hoping I'm good to go.
Glad it's not a crack. I originally thought it was too perfect to be a crack but couldn't see clearly enough if it extended further down. That's why I suggested you might try epoxy if it's a minor leak. A good case for taking a powered wire brush to see just what you have.