Caterpillar D-6c hydraulic tank leaking

[Steve.ahlgren85]

With that big of a leak you're lucky you didn't take out a pump or other hyd. component. Definitely investigate further. I think it would make more sense for a blown hose to leak that amount of oil but see Old Magnet's post above.

May not be just a seal problem, there are two sleeve bearings in there that may be worn beyond the range of the seal working.

I think that I am going to just take the tank off, take up to Ziegler caterpillar, let them go through it,hopefully they can get it fixed correctly and then warranty it. Thank you OM for your help.

 

[kshansen]

I’m not saying that you are wrong, there very well could be a hose connection or some other problem on under side of the dozer. I’m going to fix the known problem leak first which is bad after oil gets hot and is in a pressurized tank.

Well how about putting a catch can of some kind under the "known leak" and see how much it is actually leaking? I agree with Old Magnet about the bearings that shaft runs in, should only have slight side to side or up and down movement.

I'm still having a hard time wrapping my head around a 5 gallon in 3 hours leak that does not jump out on you.

Like I said before been long time since I worked on or around a D6C but wonder again if this "leak" is an internal leak and not external leak? I know the hydraulic pump is mounted on the flywheel housing but don't recall if it leaked if the oil would be going into the motor oil or into the converter/transmission oil. I might be able to see a leak into the transmission not showing up right off. Took some looking but looks like the transmission oil capacity is around 25 gallons so if estimate of 5 gallons was off or transmission was low to begin with one might not notice right off the added oil.

 

[Steve.ahlgren85]

I'd be looking carefully for corrosion pinholes or cracked welds. Welds on pipe flanges commonly crack with vibration.

That will be the next step after tank is fixed.No visable leaking on any hoses or cracked welds that I can see. Oil is dripping out very quickly after warming up! Pretty sure that’s where I’m losing it, not 100%sure though!

 

[kshansen]

I think that I am going to just take the tank off, take up to Ziegler caterpillar, let them go through it,hopefully they can get it fixed correctly and then warranty it. Thank you OM for your help.

Well good luck! But still have to wonder why you don't want to drop belly pans and remove some floor boards to check for other leaks. Even if none are found I would be surprised if there isn't a problem hiding in there that will cause a future problem from rust. Seldom dropped a belly pan that did not have lines or other parts buried in wet dirt rusting out!

 

[Steve.ahlgren85]

May not be just a seal problem, there are two sleeve bearings in there that may be worn beyond the range of the seal working.

The thing that I didn’t consider after taking the shaft out, checking for grooves, checking seal and finding seal worn out,was play in the bearings, my mistake! Shaft didn’t look worn or grooves in it so I just put in new seals, my mistake!

 

[Steve.ahlgren85]

Well good luck! But still have to wonder why you don't want to drop belly pans and remove some floor boards to check for other leaks. Even if none are found I would be surprised if there isn't a problem hiding in there that will cause a future problem from rust. Seldom dropped a belly pan that did not have lines or other parts buried in wet dirt rusting out!

Not saying that I’m not going to do that but first things first. Dropping the belly pan is not fun!

 

[56wrench]

Actually, compared to some jobs, its not that bad

 

[Vetech63]

3 pages. Steve, you have given me renewed hope my friend.

 

[Welder Dave]

There's a few posts on ways to safely remove belly pans. How is your relationship with Ziegler Cat after they tried to screw you over? Do as much investigated on your own as you can. If you're absolutely positive the leak is coming from the shaft you already repaired then it would be a good idea to have the dealer look at it.

 

[kshansen]

Not saying that I’m not going to do that but first things first. Dropping the belly pan is not fun!

Maybe not, but more fun than writing the check to Ziegler and then find out the problem is either the bearings on that shaft or something down in the belly pan!

 

[Steve.ahlgren85]

You have a great memory! Thought you would have forgotten about that incident.
Get along great with the cat dealership, great people if you pay your bills!

 

[Welder Dave]

Nobody will ever forget that "incident"! That's the same dealer that tried to make you pay them a big chunk of money and they kept the machine.

 

[Steve.ahlgren85]

Well good luck! But still have to wonder why you don't want to drop belly pans and remove some floor boards to check for other leaks. Even if none are found I would be surprised if there isn't a problem hiding in there that will cause a future problem from rust. Seldom dropped a belly pan that did not have lines or other parts buried in wet dirt rusting out!

Nobody will ever forget that "incident"! That's the same dealer that tried to make you pay them a big chunk of money and they kept the machine.

Welder Dave, It all ended well! They did a fantastic job of putting the machine back together again! I couldn’t be happier about the job they did for me. They went above what I was expecting from them!alls well that ends well.

 

[Welder Dave]

What??? As I recall vividly it took getting Cat corperate involved to get the dealer to repair it properly since it was their screw up initially. Without Cat's intervention and advice from this forum you were close to letting them keep your dozer and having to pay a large repair bill to boot. Nobody can forget that.

 

[Steve.ahlgren85]

What??? As I recall vividly it took getting Cat corperate involved to get the dealer to repair it properly since it was their screw up initially. Without Cat's intervention and advice from this forum you were close to letting them keep your dozer and having to pay a large repair bill to boot. Nobody can forget that.

You are correct Dave . All I’m saying is that in the end, everything worked out perfectly! I got a great running machine but it wouldn’t have been possible without the support and help from HEF

 

[Vetech63]

I just ordered my popcorn.

 

[Steve.ahlgren85]

The shafts wear and get grooved where the seal lip sits, did you check the shafts carefully for this kind of wear? Did you use the genuine Cat double-lip seal, or just a "will-fit" bearing house seal?

 

[Steve.ahlgren85]

Update on my hydraulic tank leak. I ended up taking tank out and putting new shaf,seal,new gaskets on the blade tilt control rod and valve body, put back together and installed then other shaft was leaking bad.pulled it off again and replaced the shaft, gaskets and the seal for the blade raise control.No leaking now! I did have to take belly pans off because there was a leak on the underside hose so you guys were right about checking on hose leaking down there,long story short, its fixed and I am going again with this beautiful old gal! I love this lady! I am posting some pictures of the seals and the machine. There’s a difference in caterpillar seals and national seals,the double lipped seal is the caterpillar seal, much better seal, in my opinion. Thanks for all your help with this issue.Merry Christmas to you all!

 

[BC Placer gold]

That a good looking “old girl”

Nice job on repairs!

 

[Steve.ahlgren85]

Couple more of the shafts I replaced

That a good looking “old girl”

Nice job on repairs!

couple more pictures of the shafts that I replaced.about $360 for the shafts,bearings,gaskets,time drilling out the old shafts and plug welding new shafts in and labor but it was worth the cost and time.