More torque for my Power trac?

[SnowRidge]

I'm glad to hear that the Model 15EV is tram pump -- it's a very commonly used pump and means that I could get it worked on somewhere other than Tazewell, if necessary. Unless I'm mistaken it was used on the larger Simplicity garden tractors with Sundstrand transmissions. They used that optional implement port to power the hydraulic implement lift -- and that circuit operated at 750 PSI...

By the way, the specs on it essentially confirmed my own "sizing assumptions" -- 2500 PSI continuous operating pressure (1250 PSI per wheelmotor) and about 14 GPM, instead of the 16 GPM I had guesstimated... and, coming full circle, that means the 12.5ci wheel motors in ideal conditions would output about 185 ft lbs of torque at 1250 PSI. To put that in perspective, that is essentially the same torque that a 185 lb person hanging onto the edge of the 23" tire would generate -- that's not a lot of torque folks...

BTW, the link you provided to the service manual doesn't work...

Fixed the link. Thanks for catching that.

I believe some Toro equipment also uses that pump.

But the fundamental question seems to be, why are some people having torque issues with their machine when otherss are not?

 

[stray]

Very good discussion we are having on this subject. I would agree or disagree and comment on all of your points and comments but I am going to wait till next week after I install the system. It is going to be interesting. Here is a diagram and a pic as to what I will be doing.

Hay now keep up the faith. I am. This is going to work . Thanks Guys

 

[ponytug]

Stray,

I will say this, you don't let moss grow. The block setup looks nice. Is the copper up to the pressure?

Good luck,

Peter

Very good discussion we are having on this subject. I would agree or disagree and comment on all of your points and comments but I am going to wait till next week after I install the system. It is going to be interesting. Here is a diagram and a pic as to what I will be doing.

Hay now keep up the faith. I am. This is going to work . Thanks Guys

 

[Bob999]

Is the copper up to the pressure?

The block looks like rusty ferrous metal to me.

 

[ponytug]

Yes...but I was looking at the protruding pipes. You need to get up to some pretty heavy duty pipe to take 3000psi...
All the best,

Peter

The block looks like rusty ferrous metal to me.

 

[J_J]

I came across these hydraulic tresting procedures, and thought you all might be interested.

Hydraulic Testing & Diagnostic | Applied.com

 

[J_J]

Stray, ,
If you are going to rearrange all the hoses, I would raise the PT up on blocks, in case you plumb something wrong, and don't dead head anything off that VSP pump. If you do, it will cost you dearly. You might do only half a circuit at a time, to check functionally. What is the material in the hydraulic manifold, and pipe?

 

[BobRip]

Fixed the link. Thanks for catching that.


But the fundamental question seems to be, why are some people having torque issues with their machine when otherss are not?

Snow, I believe there are several answers to your question.

1. The more recent PT 425s have more powerful wheel motors which PT changed for this exact reason.
2. PT changed to (I believe) 10W40 oil instead of 5W30 in the transmission. I suspect this helped some. I went to 15W50 synthetic and this helped me some. Although, I would like more torque.
3. Some people don't have slopes over 20 degrees.
4. Some people actually have something wrong with their machines, most don't.
5. Some people push their machines harder and expect more.
6. Some people push the pedal down too far when needing torque. I suspect this is a small number.
7. Hydraulic motors don't work like regular transmissions. This is kind of confusing. We expect a wheel to slip and then the limited slip diff should kick in.

Just my opinions of course.

 

[SpringHollow]

If those are threaded brass pipes, they are typically rated for 1200 psi.

Ken

 

[SnowRidge]

Snow, I believe there are several answers to your question.

1. The more recent PT 425s have more powerful wheel motors which PT changed for this exact reason.
2. PT changed to (I believe) 10W40 oil instead of 5W30 in the transmission. I suspect this helped some. I went to 15W50 synthetic and this helped me some. Although, I would like more torque.
3. Some people don't have slopes over 20 degrees.
4. Some people actually have something wrong with their machines, most don't.
5. Some people push their machines harder and expect more.
6. Some people push the pedal down too far when needing torque. I suspect this is a small number.
7. Hydraulic motors don't work like regular transmissions. This is kind of confusing. We expect a wheel to slip and then the limited slip diff should kick in.

Just my opinions of course.

I thought Stray had the White motors (high torque in PT's vernacular).