Hydrostatic transmission---non responsive

[Jim Prunetti 4]

I was driving along in my C-195 Wheelhorse and noticed a lot tranny fluid trail coming from near the filter area (I think) then quickly lost all power.  The hydro is an Eaton Model II CCW, Spec.1100032.  Pulled filter and drained all fluid. Inspected  all lines/fittings, no ruptures evident. Installed new filter and added new fluid (10-40).  Fired it up and no leaks but still no response, forward or back.  Jacked up the rear wheels and notice slight response with very occasional jerky grabbing when putting resistance on both wheels.  

Any thoughts on what I should do next?  Previous owner said hydro supposedly had been serviced ten years ago and a Woodruff key replaced...  Comments would be much appreciated.

Edited May 16, 2022 by Jim Prunetti

[rmaynard 15,588]

Did you use the correct filter?  You might have air in the system. After it sits a bit, check the fluid level again.

[953 nut 55,744]

7 hours ago, Jim Prunetti said:

noticed a lot tranny fluid trail coming from near the filter area (I think)

                                             

Sorry to meet you under such circumstances but glad you found us. My first suggestion would be to thoroughly clean the area where the leak appeared to be coming from and carefully inspect all of the hoses/hydraulic lines going to and from the transmission. A small leak under high pressure can dump a bunch of oil quickly.

Let us know what you find.

[pacer 3,174]

I think @953 nut is homing in on the possible problem.... With a big oil leak like that, it could mean something inside broke/came loose and could have cracked/damaged the case. (The early D series were notorious for this.) So, yes, give a close insp in that leak area.

[Jim Prunetti 4]

7 hours ago, rmaynard said:

Did you use the correct filter?  You might have air in the system. After it sits a bit, check the fluid level again.

I used a Motocraft FL-300 filter.

[rmaynard 15,588]

Jim, I think that is an oil filter and not a hydro filter. Should be NAPA 1410 or WIX 51410

[Jim Prunetti 4]

53 minutes ago, rmaynard said:

Jim, I think that is an oil filter and not a hydro filter. Should be NAPA 1410 or WIX 51410

Hmmmm.  Does it preform quite a bit differently?  Should I replace it immediately or just sooner than normal?  I'd imagine there's no way to do it without introducing more air into the system? 

[Handy Don 12,444]

Changing the oil in most WH hydro transmissions is regular maintenance. Unless there is a plumbing problem, including an incorrect filter, the pump is designed to evacuate any air by running the engine and exercising the lift and motion controls gently for a few minutes. In most WH hydros, the transaxle acts as the fluid reservoir and air trapped elsewhere in the circuit winds up there to be vented via the hollow curve in the top of the dipstick.

[rmaynard 15,588]

Oil filters have a bypass built in. Hydro filters do not. If you are not sure that the Motocraft is bypass-free, I'd go get a Napa 1410 to be sure.

[953 nut 55,744]

16 hours ago, rmaynard said:

Jim, I think that is an oil filter and not a hydro filter. Should be NAPA 1410 or WIX 51410

Looks the same on the outside but not correct for this application. This application chart for that filter shows it is an engine oil filter.

https://www.summitracing.com/parts/ACF-FL300/applications

[Jim Prunetti 4]

OK, I finally got my hands on the correct filter! Had to special order it.  Question:  Could I have ruined my hydro having run the wrong filter (an Automotive type) for several years?  (I wish I had found you guys sooner!)  Attempting to purge ALL the air out of the system.....  

[Jim Prunetti 4]

Still no response from the hydrostatic transmission even with the correct filter (WIX 51410), I think I've purged all the air out by forward and backward positions....  It does, thought, respond when the rear wheels are jacked up, in both directions.  I'm using new 10/40 oil and when it's warm reading 3/4 full. It apparently isn't building sufficient pressure (?).  No apparent sign of leaking underneath, though it probably isn't under any pressure to reveal itself, ha ha!    Further suggestions, please? 

[kpinnc 12,368]

On 5/20/2022 at 8:04 PM, Jim Prunetti said:

OK, I finally got my hands on the correct filter! Had to special order it.  Question:  Could I have ruined my hydro having run the wrong filter (an Automotive type) for several years?  (I wish I had found you guys sooner!)  Attempting to purge ALL the air out of the system.....  

 

The short answer- though not definitive, is yes. A standard oil filter has finite particulate capacity, and when it clogs up the internal bypass valve allows unfiltered oil to circulate. A hydro filter does not.

 

If- and that is all it is at this point, you circulated oil with metal particulates for any length of time, it can destroy the hydro. 

 

I'm not saying you destroyed the hydro. Just answering the question. 

[Jim Prunetti 4]

1 hour ago, kpinnc said:

 

The short answer- though not definitive, is yes. A standard oil filter has finite particulate capacity, and when it clogs up the internal bypass valve allows unfiltered oil to circulate. A hydro filter does not.

 

If- and that is all it is at this point, you circulated oil with metal particulates for any length of time, it can destroy the hydro. 

 

I'm not saying you destroyed the hydro. Just answering the question. 

Thanks for the information.  My next question would be is there a repair manual online for my hydro?  I plan to crack it open and see if there's anything obvious that I might be able to fix, or would that be a mistake. I've never worked on a Hydrostatic transmission before.....  The hydro is an Eaton Model II CCW, Spec.1100032

Edited May 25, 2022 by Jim Prunetti
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[kpinnc 12,368]

 

[kpinnc 12,368]

I would caution you opening the pump up before scouring the manual as well as Youtube. Definitely do your homework! You may not find much on Youtube, but you'll hopefully keep surprises at bay just by seeing what to expect. 

 

Cleanliness is the key with hydros. One grit of dirt, and they can be ruined. I mean surgical clean if you don't want to destroy it.

 

Eatons are fairly simple designs, but the ball pistons are matched to the respective ports and must stay that way for proper operation. Opening them up can be tricky.

 

Good luck!

Edited May 25, 2022 by kpinnc

[Handy Don 12,444]

12 minutes ago, kpinnc said:

I would caution you opening the pump up before scouring the manual as well as Youtube. Definitely do your homework! You may not find much on Youtube, but you'll hopefully keep surprises at bay just by seeing what to expect. 

 

Cleanliness is the key with hydros. One grit of dirt, and they can be ruined. I mean surgical clean if you don't want to destroy it.

 

Eatons are fairly simple designs, but the ball pistons are matched to the respective ports and must stay that way for proper operation. Opening them up can be tricky.

 

Good luck!

Echoing @kpinnc's advice about cleanliness and precision and avoiding surprises by being super prepared.

I watched one video of an overhaul and it put me off ever attempting one--the fellows workspace looked like a surgical suite.

[kpinnc 12,368]

1 hour ago, Handy Don said:

Echoing @kpinnc's advice about cleanliness and precision and avoiding surprises by being super prepared.

I watched one video of an overhaul and it put me off ever attempting one--the fellows workspace looked like a surgical suite.

 

It's definitely a decision one has to mull over. Unlike the Sundstrand hydros, the Eaton pumps have very little that can be repaired/ replaced internally. As a result, very few parts are available for them.

 

There are many unknowns is this case, so I'm gonna be 'that guy'...

 

I hate to say things like this, but in this case your time may be better spent locating a donor machine for a complete transmission/ transaxle. Even if you replaced the pump, it would likely be a short term fix. If your transmission has been in fact circulating grit for a while, the entire system is contaminated. The sump (gearbox), hydraulic lines, valve, and cylinder will require complete teardown and surgical-level clean overhaul. The hydro pump (transaxle) alone will cost upwards of $1500.00 if you can find one. 

 

To do it right, a donor machine (many different models used that system) is likely the safest and by far cheapest option. Obviously this comes with other considerations as well, but will be the cheapest route with the least amount of problems. 

 

Again, you may find one tiny part that is the real culprit- making everything I said just completely useless. I truly hope that is the case. You have a very nice machine that is worth keeping around.