PT-180 Tram pump issues

[ponytug]

Do you see the open gap at the top of the "after" pictures. Notice how at corner the gap closes, but on both sides of it, the gap is open?

I believe that gap is showing me the internals of the pump. AKA that gap is not supposed to be there and beyond being totally screwed up, is not allowing the pump to develop suction. Sort of like how an engine can't develop compression if there is a large hole in the combustion chamber.

Can you edit the photo and put an arrow to where the area of concern is? I may just be looking in the wrong area, but in the four photos I am not picking up on a problem gap.

All the best,

Peter

 

[James23]

Can you edit the photo and put an arrow to where the area of concern is? I may just be looking in the wrong area, but in the four photos I am not picking up on a problem gap.

All the best,

Peter

I just added a new photo. If you click then click again (to zoom) I think it becomes more obvious...

 

[MossRoad]

Do you see the open gap at the top of the "after" pictures. Notice how at corner the gap closes, but on both sides of it, the gap is open?

I believe that gap is showing me the internals of the pump. AKA that gap is not supposed to be there and beyond being totally screwed up, is not allowing the pump to develop suction. Sort of like how an engine can't develop compression if there is a large hole in the combustion chamber.

I don't think there is any pressure transfer through the pump sections. That gap shouldn't make a difference. There's a shaft in there that turns the piggy backed pumps, but it should have a seal. I think the tram pump should still work even if the two PTO pumps sections were removed. I could be mistaken, though.

As for a charge pump...

That's internal to the tram pump and not visible.

The tram pump in neutral just spins and doesn't move any fluid, because the swash plate is in a neutral position. When you push the treadle pedal, it changes the angle of the swash plate. The more positive the angle the faster you go in one direction. The more negative the angle, the faster you go in the other direction. It forces fluid through the wheel motors. So that's kind of a closed loop. But some oil slips past seals and case drains, etc. and goes back to the tank. The charge pump makes up that lost oil, and maintains a base pressure on the tram pump, as I understand it.

Also, the hydraulic filter only filters any fluid that the charge pump sucks in to the tram pump (suction filter). It doesn't filter any fluid in the PTO pumps that are constantly pumping. They have a separate intake(s) from the tank than the tram pump.

I'd guess when you install a new tram pump, you'd have to fill the unit with oil manually, then perform the bleed procedure until no air comes through the bleed hose back into the tank. If you're still getting air bubbles after several total minutes of bleeding, there's a couple reasons that I can think of.

Very low level in the hydraulic tank.
Filter not sealed to the filter housing.
Pump wasn't filled with fluid before attempting the bleed and doesn't have enough fluid in it to start suction.

If you're getting not oil coming out of the bleed hose, don't run the engine until you can get the bleed hose to pump out only oil into the tank by just cranking the starter in 10-15 second bursts (to keep from overheating the starter) with the spark plugs removed so the engine doesn't fire.

 

[MossRoad]

I just added a new photo. If you click then click again (to zoom) I think it becomes more obvious...

ahhh, I see. That's a part of the tram pump, not the space between the tram pump and the piggy backed PTO pumps, correct?

 

[James23]

ahhh, I see. That's a part of the tram pump, not the space between the tram pump and the piggy backed PTO pumps, correct?

Yes, to me that is part of the tram pump. Now I feel like that should all be sealed up, but I'm not entirely certain.....

The smaller pumps connected further back (that each have a hose on the left and the right) are working fine.

 

[ponytug]

Yes, to me that is part of the tram pump. Now I feel like that should all be sealed up, but I'm not entirely certain.....

The smaller pumps connected further back (that each have a hose on the left and the right) are working fine.

In your fifth picture, I now see your area of concern. It does seem like you can see into it which seems...not right. I notice that there is a seal on the engine side of that gap, which leads me to believe that the area you pointed out should also have a seal, and in your great photo, you can see some ways into that gap.

If it were me, I would email Terry that photo, and explain your concerns.

If you are up for some non-destructive testing, I would pour some oil into the suction filter hose, and see if any comes out your gap.

All the best,

Peter

 

[cqaigy2]

I'm trying to remember what i did when changing my tram pump, but seemed like i filled anything that would take oil, pumps, hoses etc. And refill the many gallons of oil i let leak out onto the floor.

I did have one occasion after replacing oil filter where it leaked air around the seal. It takes a lot more turning then one would expect, from changing oil filters on engines. I can't hand tighten the hydraulic filter enough, i have to use a wrench to get it tight enough.

It will be interesting to see what Terry has to say about your pics. Nice pics by the way.

 

[MossRoad]

Now enhanced for my trifocal eyes.

 

[oldnslo]

I am not sure what a charge pump is, but if you are asking if I am literally missing a hydraulic pump of some type, No is the answer to that. All of the pumps that came with the tractor are on there, nothing removed.

James
I believe Mossroad answered the question on charge pump location but if it does not prime the HST will not work. I could not tell on the pictures which hose is the charge pump inlet but again per Moss it should be the line from the filter to the tram pump. This must be full of oil for the pump to operate. From what you are describing the charge pump is not priming to bleed the system.

That gap could be part of charge pump but again without knowing make and model of pump not sure.

 

[James23]

So Power Trac is closed for the week. I will update this post next week after I talk to Terry. I am going to inspect is further this weekend, if I find anything new I will update.