Pulling engine on 743. What parts to replace while im in there?

[willett]

Hey guys, Theres a pretty good leak coming from somewhere down deep in my 743. I think the control spool might be leaking or one of the hard lines for the aux hydraulics rotted through. At any rate it looks like I'm pulling the engine to get it repaired. I'm an HD mechanic for a living with a good selection of speciality tools. What should I replace while I'm in there? Can I replace the joints in the pump coupler or does the whole assembly need to be replaced? I'm going to the valve set while the engine is out as well. So far on my parts list: Control spool seal kit Manifold to pipe exhaust gasket Pump coupler parts Anything else? Its a v1702 Also if anybody has these part numbers on hand send em my way

 

[Tazza]

The most likely point of a leak is undet the control block, there is a hose that makes a U shape that is a very common failure point.
Tube lines can rub through, i have removed them, wire wheeled the damaged poin and brazed over the hole with perfect success.
As for the U joint. With the engine oil, feek if there are any gritty bits when moving it or any slop, if so, replace it. If you don't feel any, it's your call if you replace it or just give it a good grease. There are two spiders (if they call it that over there) that makes up the universal joint, one either side of a metal spacer.
If you look up my profile, send me an email to look up the part number for the universal joints, i have them at home..... somewhere.....

 

[willett]

The most likely point of a leak is undet the control block, there is a hose that makes a U shape that is a very common failure point.
Tube lines can rub through, i have removed them, wire wheeled the damaged poin and brazed over the hole with perfect success.
As for the U joint. With the engine oil, feek if there are any gritty bits when moving it or any slop, if so, replace it. If you don't feel any, it's your call if you replace it or just give it a good grease. There are two spiders (if they call it that over there) that makes up the universal joint, one either side of a metal spacer.
If you look up my profile, send me an email to look up the part number for the universal joints, i have them at home..... somewhere.....

Thanks for the info. I got the spool block put today and now she's soaking in the solvent tank. I'll pop the quad rings in the AM. The leak ended up being the spool return hose off the bottom of the block like you suggested. My aux hard lines aren't exactly looking great either, I'm going to cannibalize the unused rear aux hard lines and replace the rusted out straight sections of the front aux lines. Bobcat wants about $160 per line and I'm a cheap bastard with a lathe and a tig welder. Wouldn't the pump inlet seal just be holding back case drain pressure? I'm in Canada so every time I have to order something small like a seal I end up paying more in conversion, shipping, and duties than the part is actually worth.

 

[Tazza]

Thanks for the info. I got the spool block put today and now she's soaking in the solvent tank. I'll pop the quad rings in the AM. The leak ended up being the spool return hose off the bottom of the block like you suggested. My aux hard lines aren't exactly looking great either, I'm going to cannibalize the unused rear aux hard lines and replace the rusted out straight sections of the front aux lines. Bobcat wants about $160 per line and I'm a cheap bastard with a lathe and a tig welder. Wouldn't the pump inlet seal just be holding back case drain pressure? I'm in Canada so every time I have to order something small like a seal I end up paying more in conversion, shipping, and duties than the part is actually worth.

Glad it's out, much easier to work on when on the bench, especially putting the detent balls back in. If the rust isn't too bad, tig the holes up, saves a lot of work, but at least you have the gear to do it. The pump seal will be at charge pressure, not case drain, so about 120psi. The charge pressure is there to feed the piston pumps. As for being cheap, aren't we all? if i can do the job, i'll do it myself.