TD7E leaking from Torque Converter

[William Creek]

I think my problem is in the same area. I was working on the driveway and the blade angle hydraulic cylinder was leaking badly. I stopped the machine, removed the cylinder and had it repaired. Reinstalled it, fired up the machine and everything was fine for about 30 seconds. Clutch pressure then fell to zero. A large quantity of hydraulic fluid was flowing from beneath the engine but I am unable to locate the source. The main hydraulic tank is absolutely full The fluid level stick under the floor plate is on "add fluid". The blade vertical movement works just fine, but the tracks . . . not an inch in forward or reverse. It's pretty clear something is leaking badly, but where do I start looking?

 

[William Creek]

Nope, not even close. I temporarily filled the converter filler tube to get the level correct and started the engine. Clutch pressure came up momentarily and it began to spew hydraulic fluid toward the far front end of the dozer, as in, "oil cooling radiator". I still can't see an actual leak or hole. It must either be the cooler or some hose running to it. Still looking for advice. Thanks if you see this.

 

[Willie B]

I had two Case 580K backhoes with similar set up.
I also have a TD7G, nearly the same dozer but 3900 CC Cummins instead of IH engine.
All have leaked when warm. Minor leaking, I just kept it full. As they get worse, they need repair.
The last Case, I sent off to the dealer. Memory serves poorly sometimes. Seems like it cost $50.00 for parts, $950 for labor.
In a dozer labor is going to be a lot more.

 

[William Creek]

I have found the problem. One of the hoses running to the oil cooler has exploded. I can't even wiggle the thing to see where it is attached. Had to half way remove the radiator to see what looks like an engine mounting bracket with a "notch" in it to assist in hose removal. The destroyed hose was the "hot oil" line coming from the transmission. The closest I get to a "point of attachment" is from a cooling system schematic in the service manual. But this is only a schematic. The hoses running back toward the transmission are packed so tight (and may have tie downs) I can't see exactly where this hose attaches to the transmission. I'd rather not just start pulling hoses to find the dead one. It's been disconnected from the oil cooler end but if I wiggle it around I can't see anything moving back by the transmission. The diagram is useless for an exact location and there are no pictures. Can somebody please tell me the best way to find that connection point? Do I access this hose from underneath the dozer or from above? I have the foward plate removed, but the plate under the operators seat (transmission) is still attached. Does that need to come off?

 

[William Creek]

I have found the problem. One of the hoses running to the oil cooler has exploded. I can't even wiggle the thing to see where it is attached. Had to halfway remove the radiator to see what looks like an engine mounting bracket with a "notch" in it to assist in hose removal. The destroyed hose was the "hot oil" line coming from the transmission. The closest I get to a "point of attachment" is from a cooling system schematic in the service manual. But this is only a schematic. The hoses running back toward the transmission are packed so tight (and may have tie downs) I can't see exactly where this hose attaches to the transmission. I'd rather not just start pulling hoses to find the dead one. It's been disconnected from the oil cooler end but if I wiggle it around I can't see anything moving back by the transmission. The diagram is useless for an exact location and there are no pictures. Can somebody please tell me the best way to find that connection point?

 

[John C.]

Pull the belly pans and clean the thing out for access to the hose and piping. Sounds like it needs cleaned out anyway.

 

[Willie B]

Pull the belly pans and clean the thing out for access to the hose and piping. Sounds like it needs cleaned out anyway.

TD7g was 28? years old when I got it. The story was a one owner, old man bought it new. 3500 hours, with an aftermarket chains & non standard shoes.
There must have been 400 LBS of oily dirt in the belly pan! There was a leaking big hose, a specialty part from Dresser. Somebody had tried to make up the hose, that wasn't going to work, too tight bend radius, it needed a $450. molded hose from Dresser.

 

[B mac]

thinking about buying 1991 td7g but transmission oil is coming out around the bell housing is that bad thing

 

[g_man]

Definitely not good. Sounds like maybe the torque converter seal. Once it is off might as well rebuild it. Mine is a 91 also.

gg

 

[John C.]

That could mean all kinds of expensive and hard to find parts for kinds of problems. A partial list of issues could be a bad torque converter with worn out turbine, stator and impeller. Maybe a broken or worn out scavenge pump. Could also be problems in the transmission. Rule of thumb back in those days was to pull both the torque and the transmission for overhaul at the same time. The process is akin to opening a casket.

 

[Willie B]

If I'm not mistaken g_man's machine is within 500 in serial number from mine. If he is sure of his year of manufacture, I'll say mine is close to his vintage.

Mine was an oily mess because of a leaky hose under the torque converter. It is a large hose & tight bends mean it pretty much has to be pre formed. Mine came from Komatsu they service Dresser parts. The hose was near $500. with tax & shipping.

 

[John C.]

Oil from the housing is what caught my eye.

 

[Willie B]

Case 580 K backhoe has identical engine. I can't say about the torque converter. I've had two 580K backhoes. First only leaked in very hot weather. I kept it full & otherwise ignored it.

Second seeped all the time, a pint every 6 months, then one day is leaked profusely! I took it to the dealer. The bill was $1000. & parts were $50.
These tractors looked identical except The first had a threaded hole in the bell housing, the other was open with no obvious way to plug it. I filled it with silicone caulk to keep bees & rodents out. Case offered a tool to service, a gear replaced the starter you could turn the engine with to expose a drain on the torque converter. There should be no leakage from the bell housing, but I'd not be alarmed if it is minor.

 

[B mac]

After evening is disconnected around a torque converter in a “TD7G” dresser should I just pop off or is there something else holding it