Caterpillar D-6c hydraulic tank leaking

[Steve.ahlgren85]

I have a D-6c serial#10k10536 about a 1976 year dozer that has an oil leak coming from the control rod coming out of the hydraulic tank. Resealed the rod thinking that would solve the problem, reinstalled the tank, not an easy job, still is leaking, very frustrating!Anyone else ever experience this problem? Any suggestions would be greatly appreciated!

 

[Vetech63]

OMG! Steve!!!!!…….I’m soooooo happy you have another problem!

 

[OzDozer]

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]

I did a visual and hand rub check , no groove on leaking shaft. Did not use cat seal , maybe that is where I made a big mistake. The seal was national seal so I just ordered the seal from Napa.thanks for the reply!

 

[OzDozer]

Yeah, you have to keep in mind that Cat do not necessarily follow SAE standards, nor do aftermarket manufacturers necessarily produce items to Cat specifications.

Cat will change specified measurements and materials to suit their own ideas, often to improve durability.

I've had Cat bearings that were standard dimensions for outer and inner measurements - but they had .002" additional operating clearance between rollers and races, which made them a "proprietary bearing", and bearing houses were unable to supply the precise bearing.

I could buy a standard bearing and risk a shorter lifespan or pay extra for the Cat bearing and get the designed lifespan.

The same goes for seals, Cat will produce seals made with more heat-resistant seal material, whereas aftermarket seals will use a generic seal material.

Cat also tend to use double lip seals a lot, and an aftermarket supplier will often provide a single-lip seal as a "will-fit" offering.

 

[Steve.ahlgren85]

That makes perfect sense, just wish I would’ve checked that out. I’m going to take it back out and replace the seals with cat seals. Should the shafts and inner bearings be replaced if there’s no visible wear on the surface of the shaft?

 

[OzDozer]

If there's no visible wear on the shaft, there should be no problems. Feel for shaft sideways movement, there should be very little, a few thou at most.

 

[Steve.ahlgren85]

Thanks ozDozer for your input, you are very helpful.

 

[Welder Dave]

Inquiring minds want to know how your dozer has been running since you finally got it back fixed properly?

As far as the seal could the leak be from somewhere else? Even though Cat may use a double lip seal it seems if a single lip f its tightly it should still seal although won't last as long or seal quite as good. Double check there's no groove forming on the shaft. If there's even slight wear a speedi-sleave might be a good option. Put a couple drops of oil on the seal when you install it on the shaft.

 

[Steve.ahlgren85]

Dozer has been running great. No problems except minor issues, track tensioners needing new seals, bolts broke for alligator connection link, had to replace,I’ve put about four hundred hours on the machine, nothing to complain about, great running tractor.

 

[Steve.ahlgren85]

Welder Dave, oil is dripping from the shaft where it connects to the length adjustment rod for the blade tilt. No visible groove on the shaft, real smooth surface. I was thinking that maybe I should have filled the tank halfway with water and checked it before putting it back together, maybe the leak would have shown.

 

[Welder Dave]

Glad that it has been running great!

I wouldn't put water in the tank. That's just asking for problems. I wasn't sure where this shaft came out of the tank so having the proper Cat seal may be all that's required. Make sure it's installed the right way.

 

[OzDozer]

Never put water in any hydraulic system, if you want to test for leaks, use diesel.

The D6C is one of Cats finest machines ever built, Cat built their reputation on these tractors.

As a full-time contractor, I part-owned 2 of them with the brother, bought both new, did D7-type work with them, wore them out as far as I was concerned, traded them with over 13,000 hrs on the clock, after 6-7 years of hard work - and would you believe it, the brother just recently found the first D6C we bought, it's 57 years old, and still working!!

It's probably done over 50,000 hrs by now! However, it's largely out to pasture, an old prospector owns it, and only uses it part-time.

 

[Steve.ahlgren85]

Thanks ozDozer for the tip about using diesel fuel to check for leaks. This D-6c is a great,Very! reliably machine! That’s alot of hours for a machine that old of a machine!

 

[Welder Dave]

There should be disclaimer to the statement, This D6C is a great, very! reliable machine! This D6C was the subject of the most epic thread in the history of this forum and likely any forum for that matter. It is great that it got sorted out and is working good.

Using water to test for leaks in the hyd. tank I'm sure would have delighted Vetech63 and shares in popcorn would have gone up substantially.

 

[56wrench]

Is there not an o-ring that seals the bearing assy to the side of the tank, and if so, did you change it too?

 

[Steve.ahlgren85]

No o-ring that I could see, just a seal on the rod end in the tank with the rod coming through the tank, then the bearing on back end of valve block. I’m thinking maybe the bearing had some play in it causing the rod to move enough to not seal well.

 

[Mcrafty1]

Never put water in any hydraulic system, if you want to test for leaks, use diesel.

The D6C is one of Cats finest machines ever built, Cat built their reputation on these tractors.

As a full-time contractor, I part-owned 2 of them with the brother, bought both new, did D7-type work with them, wore them out as far as I was concerned, traded them with over 13,000 hrs on the clock, after 6-7 years of hard work - and would you believe it, the brother just recently found the first D6C we bought, it's 57 years old, and still working!!

It's probably done over 50,000 hrs by now! However, it's largely out to pasture, an old prospector owns it, and only uses it part-time.

That truly Amazing, Makes me wonder if in today's throw away world the machines of today will be around 57 years from now and still operable. If so, I wonder what condition the plastic parts will be in?

 

[Steve.ahlgren85]

Is there not an o-ring that seals the bearing assy to the side of the tank, and if so, did you change it too?

Here’s a parts diagram that I got online.

 

[Nige]

What’s the Hydraulic Control Serial Number.? It will be on a plate on the side of the tank, probably a 163-something.

I can try to find a parts listing relevant to that particular S/N. It may be different to the diagram you have.