Howdy, so i've got my d3b and put maybe 10 hours on it. The hydraulics were acting up so i dipped the tank (my sight glass is very crusty) and it was pretty low. There was no obvious sign of a major leak i dropped both belly pans. I left some fresh cardboard under it to see if it drips anything new (it's got some drips but i don't think anything major enough to account for that kind of loss). The hydraulic reservoir was full (18g) when i started putting those hours on it. When i changed the engine oil there was a massive amount of oil. Like 3-5 extra gallons on top of the 3 it normally takes. After the hydraulic reservoir was low I checked the oil dipstick and it was very overfilled. Is there somewhere on the engine that runs a hydraulic pump where a bad seal could be leaking hydraulic oil into the motor oil? I will drain the oil and fill the hydraulic back up and check again, but figured I wasn't the first person to run into this. Any ideas are appreciated. Oh also my exhaust usually has a pretty strong blue smoke to it, even after filling the oil to the proper level. I figured it was just some blow-by so an engine rebuild is probably in it's future. But it could also be the extra oil filling it up right away again not sure. It seems to be a bit low on power but it's the only one i've run so no comparison.
Yeah the seal in the hydralic pump bolted to the left side of the engine is leaking
Awesome, is there a seal kit to rebuild it? I’ll check the parts diagram
Probably should just get a new pump gear pumps like those used here once worn are junk do to the housing getting warn
And that’s a good reason why checking all the fluids before every use is important. Even if only for a couple hours.
If you had quoted a machine Serial Number someone might have been able to come up with a seal kit Part Number or possibly even other alternatives.
3204's are known to have blow by due to only having 2 ring pistons. I would certainly determine if the pump just needs a new seal before replacing it.
All good I looked it up on Cat, the real question is the new pump a definite buy ($5-600) or will the $10 seal kit give it some more life? In the manual the pump disassembly and reassembly looks like a pain but is it just an easy to access seal that leaks?
The pump needs to be inspected which can be done when taking it apart to change the seal. A good hydraulic shop or the Cat dealer could visually inspect it for anything obvious and bench test if necessary. Even if it looked OK and you just replaced the seal you're not out much if there is a problem with the pump. I think there's a good chance it might just need a new seal but can't say for certain. Would be a good idea to change the hydraulic filter. Doesn't take much dirt to take out a seal.
IMO a seal kit on a small pump is a crapshoot. Seems like it's a 50/50 deal whether or not the shaft is worn out from the seal. If it were me I'd pull the pump apart to inspect it first but I'd anticipate needing to replace the pump.
If the shaft is worn a speedi-sleeve may be an option or metalizing the shaft with spray welding. That's how the main shaft on my rotary swing cylinder was repaired. We don't know how many hours are on the pump or anything else. Would want to thoroughly inspect the pump before dropping $600 or more on a new pump. Most small dozers I've seen usually don't have a lot of hours on them. Most seem to be under 7000 hours.