Hydraulic maintaince questions

[ponytug]

Udpate:

The leak appears to be out of the body of the motor about 2.5" back from the motor face with the hydraulic fittings.

The Fix:
Terry is prepping a motor with the minor hydraulic fittings and sending it out. I'll replace it and send mine back to him.

More as it unfolds.

Peter

 

[ponytug]

Hopefully Final Update.

Swapped out the old motor for the new one. 85lbs of motor. Not the easiest item to manouver into its mounting hole. I am sure more experienced mechanics will have suggestions on how to make this easy, but I will hope that I don't have to do it again.

Tools need:
Clean towels, compressed air, and degreaser.
Caps for both motors, and caps for the 4 hoses.
1 1/4", 1", 9/16", 5/8" 90 degree wrenches, and
a big crescent wrench helps for the motor bolts.
a 5/8" crowsfoot wrench for the case drain, and a stubby to hold the case drain hose.
A torque wrench for the wheel lugs. (60-80ft-lbs, per Terry)
Jack and jack stands, or railroad ties.

I used lots of compressed air and degreaser. It seems as if dirt was breeding like tribbles, but Terry's advice had been to treat it as open heart surgery, so I gloved up and disinfected the patient. I think we kept the blood loss to less than a 1/4 cup. I didn't spill very much hydraulic oil either.

Thanks to Terry, the new one was 90% ready to drop in. As a number of you had mentioned, having enough caps and plugs is essential to keep the swap from becoming the Exxon Valdez II. I had to improvise a set for the extracted motor. i.e. that is two sets of caps for the two motors and one set for the hoses. Duh!

The Harbor freight 90 degree wrenches were great, except that three of them weren't the right size. Talk about shoddy products. The motor case drain practically requires a crowfoot wrench to tighten.

Attached are two photos of the extracted motor. As you can see, there is the frayed remains of an O-ring protruding from the motor housing. The ends are indicated by the yellow arrows. The second photo shows the oil weep in more detail. Oil runs out of this space under no pressure. Turning the motor upright for the photos caused a tablespoon or two to weep out.

I have run the tractor for a few minutes with no leaks, so I hope that it is fixed.

Having the tractor up on blocks was a useful learning experience. I found that the solenoid wiring harness for the hydraulic oil cooler had fallen off the solenoid. (I tie wrapped it to the solenoid to counteract the effects of gravity.) I also found a sharp edge in the tunnel, just as the hoses turn from horizontal to vertical and pass under the forward bearing for the articulation. (Conveyor belting on top of the hoses.) I'm still working on getting all of the hoses protected where they rub.

All the best,

Peter

 

[ponytug]

Just a quick follow up. I replaced the other rear wheel motor today, and it goes much faster the second time. This motor had been weeping oil since the beginning, but I, and I think Terry, had hoped that the oring would settle in, but apparently not.

This time through, the wheel motor was 'naked', so I had to transfer the old hardware to the new motor. I had a slight difficulty with the aluminum "T" block assembly that "tees" off hydraulic fluid to the other rear wheel. I had to put a cheater bar on the wrench to get it loose from the old wheel motor.

Oh, and in case you are wondering, the motor that PT sent me was the same one from the above picture, with the blown o-ring repaired. So, PT can't have the wheel motors fail all that often. (as in less than once a year...)

To explain why both the rear motors failed, all I can think of is that the ground here is very steep and just moving the tractor around in the first couple of hours might have put too much stress on the motors too soon. (Which might be why Eaton recommends running the motors at 50% power or less for the first five hours.)

I can't say enough great things about Terry. Very helpful and humorous throughout the whole thing. Especially when I called up to ask about why the durn fitting wouldn't come off the motor. His reassuring comment was along the lines of "ain't nothing you can do, that I can't fix." That gave me the confidence to go out and lean on it, so to speak. A cheater bar and about thirty seconds later, the fitting came off sweet as a daisy. I was just too cowardly to put mongo amounts of torque on a high precision piece of machinery like a hydraulic motor.

All the best,

Peter

Additional tools used:
8mm allen wrench to remove the main plugs on the motor. (might have taken a 3/8", but it seemed good.)
Cheater bar.
Adjustable wrench large enough to go over the aluminum "Tee" housing, 12"
Locktite to replace a bent wheel lug bolt
Power washer to get all the old oil off the motor, and surrounding area.
Presoaking with Dawn dishwasher liquid.
Managed to get the case drain off and on, without the crows foot wrench this time.
Don't forget all the caps, and plugs!

 

[woodlandfarms]

Peter, thanks for all the good info. Do you mind telling us how much the wheel motor was, or was it Warranty?

Also, I am the first one to not put too much pressure on breaking hoses free. But PT really has some big guys in the shop with long cheater bars cause that is what it has taken on several occassions to get things apart.

When I replaced my PTO hose, I could not get the connector off. I sawzalled the hose and took it to the hose shop. There, 3 guys did some crazy stuff and never got it to come off... I guess PT does not own a torque wrench?

 

[ponytug]

It was still covered under warranty, but I believe that they run about $1840/motor, plus freight.

The "Tee" is aluminum rectangle shown in the image below (Upper arrow.) The lower arrow points to an adjustable spacer that adapts from the SAE o-ring fitting to the aluminum block. The block had been fastened to the fitting with sufficient pressure to indent the steel washer with a hex pattern from the nut. I hope this clarifies the issue. I think that the fitting was fastened to the motor, and then aligned by rotating the aluminum block into the stalled nut.

I am sure that PT has a torque wrench and I am equally sure that there are a number of fittings that via the pressure cycling get really embedded. I would love to know the early history on your machine; i.e. what was the reason that it got retired to be a donor machine for the other one.

Having bought a new PT, there were at least twenty fittings that needed tightening at the five hour mark and probably a dozen needed it by the twenty hour mark. But since then, the fitting seems to have settled in and don't leak. Terry's advice on the fittings was torque them just until they don't leak, which strikes me as a YMMV specification, but one that I follow. Nothing that I have tightened has required excessive force.

All the best,

Peter

Peter, thanks for all the good info. Do you mind telling us how much the wheel motor was, or was it Warranty?

Also, I am the first one to not put too much pressure on breaking hoses free. But PT really has some big guys in the shop with long cheater bars cause that is what it has taken on several occassions to get things apart.

When I replaced my PTO hose, I could not get the connector off. I sawzalled the hose and took it to the hose shop. There, 3 guys did some crazy stuff and never got it to come off... I guess PT does not own a torque wrench?

 

[woodlandfarms]

Thanks for the picture Peter. You guys are right about how no one PT appears to be the same... I assume this picture is taken looking down, right behind the fuel tank. 22 and 11 are your PTO return and run, at your head (camera top) is draft control?

So that T connector I do not have.... I am really intrigued in its purpose. Hose 38 and the unmarked are your wheel motor hoses, right? Do you know where that T feeds into?

Ken may have more information on my PT, but this is what I think I know. There was a guy back east who had a slope mowing company. He also clearly had no concept of maintenance. Anyway. He bought this PT I think in 2002 and was doing state road maintenance. About 200 hours into operation he burned the motor up. After a fight with PT and Deutz he said he got a new one for free. His boys installed the mower, took it up to the highway to test and they melted down the electrical (It to me looks like they shorted the starter solenoid as the grill is melted there). Now he has this big contract he has to get done so he orders parts to fix the PT, but also orders a whole new one (Kens). But, he is lazy and crazy and never fixes mine, just leaves it outside and pulls parts from it. It was sold as a parts to Ken, and Ken decided to invest in fixing it up (thank you Ken). Ken and I talk frequently, he is one great guy. It is up for argument which of us got the better deal. We both seem to have weird stuff happen to our machines, but I abuse mine and Ken knows how to treat equipment.

One weird side note is that my PT does not have a serial number. Terry says that they have no record of this guy buying this tractor initially, but that did not mean much as PT is not great about records. Terry said it was not a questionable purchase. But without the serial I cannot get any accurate dates on construction or version history.

I am enclosing a picture of my PT, I think I have shown this before..

Oh, I have to say that is one of the cleanest tubs I have ever seen Peter.... Really impressive. Like you don't even use the tractor ;-)

 

[ponytug]

To clarify:

The photo is taken looking vertically downward centered over the left, rear, hydraulic motor. On the left side of the image is a control block that has the PTO in it (hoses 111, 22) and the small hose (21) snaking horizontally across the image above the wheel motor connects to the brake accumulator off the image to the right.

The "Tee" enables hydraulic fluid to flow from one wheel motor to the other, enabling a differential like behaviour. In principle, I think that this could also occur at the hydraulic pump, but PT has it plumbed up this way. (Perhaps to reduce turf tear up?)

The clean tub is a direct result of Terry suggesting that wheel motor repairs were to be regarded as open heart surgery, and everything was to be spotless. Since the oil is recirculated from the wheel motors to the pump back to the wheel motors and the only escape is via the case drains, any dirt that gets in, is in there for the duration, until it is ground down fine enough to bypass into the case drain. As a result, I tried really hard to get it all clean, include the small cracks next to the fittings. When you go to disconnect and move the hoses, you definitely find out how good the initial cleaning is. Having done it twice, I am now getting pretty good at removing all oil and dust. (Hint, don't forget to clean the tractor, again, after removing the wheel.)

But, yes, I try to keep the tub clean, per JJ, and to ensure that I manage any hydrocarbon spills in a defined location, rather than spread around the property. I am still getting oil off the tractor from the first seal rupture, which sprayed oil everywhere at high pressure. Dawn works really, really well. (Plus, the photo was taken when the tractor was new. But it is that clean now.)

All the best,

Peter

Thanks for the picture Peter. You guys are right about how no one PT appears to be the same... I assume this picture is taken looking down, right behind the fuel tank. 22 and 11 are your PTO return and run, at your head (camera top) is draft control?

So that T connector I do not have.... I am really intrigued in its purpose. Hose 38 and the unmarked are your wheel motor hoses, right? Do you know where that T feeds into?

Ken may have more information on my PT, but this is what I think I know. There was a guy back east who had a slope mowing company. He also clearly had no concept of maintenance. Anyway. He bought this PT I think in 2002 and was doing state road maintenance. About 200 hours into operation he burned the motor up. After a fight with PT and Deutz he said he got a new one for free. His boys installed the mower, took it up to the highway to test and they melted down the electrical (It to me looks like they shorted the starter solenoid as the grill is melted there). Now he has this big contract he has to get done so he orders parts to fix the PT, but also orders a whole new one (Kens). But, he is lazy and crazy and never fixes mine, just leaves it outside and pulls parts from it. It was sold as a parts to Ken, and Ken decided to invest in fixing it up (thank you Ken). Ken and I talk frequently, he is one great guy. It is up for argument which of us got the better deal. We both seem to have weird stuff happen to our machines, but I abuse mine and Ken knows how to treat equipment.

One weird side note is that my PT does not have a serial number. Terry says that they have no record of this guy buying this tractor initially, but that did not mean much as PT is not great about records. Terry said it was not a questionable purchase. But without the serial I cannot get any accurate dates on construction or version history.

I am enclosing a picture of my PT, I think I have shown this before..

Oh, I have to say that is one of the cleanest tubs I have ever seen Peter.... Really impressive. Like you don't even use the tractor ;-)

 

[woodlandfarms]

So, help me out on this one because the 1850 with the wider stance has a bit of a tear up the turf tenancy...

You are saying that from this T at your rear wheel (This is the only T connection, right?) a hose runs up and connects to the wheel motor on the same side up front? This is where hydraulics all falls apart for me...

 

[ponytug]

The "Tee" goes from the left rear wheel to the right rear wheel. While I haven't fully traced the front hydraulic system, it is missing the aluminum block, so I don't think that there is a special system for it.

Attached is a view of the front wheel motor. Notice the straightforward 90 degree hose setup, and case drain.

All the best,

Peter

So, help me out on this one because the 1850 with the wider stance has a bit of a tear up the turf tenancy...

You are saying that from this T at your rear wheel (This is the only T connection, right?) a hose runs up and connects to the wheel motor on the same side up front? This is where hydraulics all falls apart for me...

 

[J_J]

So, help me out on this one because the 1850 with the wider stance has a bit of a tear up the turf tenancy...

You are saying that from this T at your rear wheel (This is the only T connection, right?) a hose runs up and connects to the wheel motor on the same side up front? This is where hydraulics all falls apart for me...

Carl,

On my 1445, the pump fluid in the FWD mode, goes to a tee. then back to another tee which branches off to the wheel motors. The fluid also goes up to the front to another tee and then to the front wheels. The reverse path used a similar set of hoses. If I remember right , the wheel drain lines either go to the cooler or goes to the case drain and then back to the cooler.

They may use a block fitting or a tee fitting. They do the same thing.