PTO pump stalling tractor .

[Swamp Rooster]

Hello every one . I was talking last week about getting a PTO pump to rum my log loader . I did and I went with this pump 16.6 gpm at 540 rpm . I have it all mounted , made a bracket for it . It seems to want to really work the motor on my Tractor to run the pump . The loader requires 9 to 11 GPM to rund . I was told that I could just idle my motor down and the pump would handle it well . Even at 2000 and 540 it really lugs down..
I was thinking that I was trying to move to much volume of oil ? Thought the pump might be to big .. Any thoughts .. I will try and post some pics .. Tractor is a TC33 Browser no longer supported Browser no longer supported 7.62 cu in 16.6 GPM 54 RPM Dynamic GP-PTO-A-7-6-S Hydraulic PTO Pump | Dynamic | Brands | www.surpluscenter.com

 

[CADplans]

In your case, typically,, 1GPM @ 1,000 PSI = > 1HP

so,, 16.6 GPM @ 2,000 PSI can easily equal > 33+ HP,, you have about 28 PTO HP,, so,, there should be an issue,,

reduce the pressure a little,, until the tractor is "happy",,,

 

[Sawyer Rob]

If you have a hydro TC33, you have just under 27hp at the pto, that pump would be a pretty good load when it's at max pressure...

Keep in mind, when you are moving/working, you have other things on that tractor robbing hp from your engine too, all at the same time...

Also, do you have a flow restriction some place? Like a bottle neck for the hydraulic oil??

SR

 

[Swamp Rooster]

In your case, typically,, 1GPM @ 1,000 PSI = > 1HP

so,, 16.6 GPM @ 2,000 PSI can easily equal > 33+ HP,, you have about 28 PTO HP,, so,, there should be an issue,,

reduce the pressure a little,, until the tractor is "happy",,,

How do I reduce presser ?

 

[Swamp Rooster]

My TC33 is gear driven ..

 

[Industrial Toys]

Do you have relief valves you could back off on? You should not need much hydraulic performance for a log loader. Not like a snow blower with hyd motor.

Actually I just thought about this. It is probably an open center system, so there should be oil flowing through your spool at little pressure with no function selected. When you select a function you will build pressure as your cylinder is operated and go into relief at end of stroke.

 

[Swamp Rooster]

Do you have relief valves you could back off on? You should not need much hydraulic performance for a log loader. Not like a snow blower with hyd motor.

Where would I look for that ? I am not sure .

 

[Industrial Toys]

I edited my post. I guess reliefs are either on the pump or valve spool. But no reason for them to be in relief when nothing is being operated.

 

[Swamp Rooster]

I edited my post. I guess reliefs are either on the pump or valve spool. But no reason for them to be in relief when nothing is being operated.

Could it be right on the pump ?

 

[ptsg]

Looks like you have a combination of various things creating all kinds of problems.

On the other thread, you mentioned it used a Honda engine with a pump to run the log loader. That pump is probably around 5-6 GPM and the whole hydraulic system of the loader was design around this GPM.

Now, you increased the size of the pump for one that over 2,5 times bigger than the stock one. The rest of the system, as in size of lines and GPM that the valve block can handle was not designed for a pump this big. This will create all kinds of problems. Most likely the stock lines are 3/8", that can't definitely handle this much GPM of the new pump, hence causing restriction even just with the system idling.

Even though you can reduce the system pressure, you're going most likely to still have problems with that pump.

The relief valve is usually on the control valve body.

 

[Industrial Toys]

I am not sure. But why is it building pressure in it's idle state? It should be pumping from the tank, going through the spool and back into the tank with little pressure being developed.

 

[RickB]

If you have a hydro TC33, you have just under 27hp at the pto, that pump would be a pretty good load when it's at max pressure...

Keep in mind, when you are moving/working, you have other things on that tractor robbing hp from your engine too, all at the same time...

Also, do you have a flow restriction some place? Like a bottle neck for the hydraulic oil??

SR

If he is stuffing 16 gpm through a valve rated for 11 that is a restriction right there. Lowering ERPM enough to drop the flow to the valve capacity might cut the available hp below the requirement needed to turn the pump at that load.

 

[ptsg]

I am not sure. But why is it building pressure in it's idle state? It should be pumping from the tank, going through the spool and back into the tank with little pressure being developed.

The lines are small for that GPM on the new pump. So it will create restriction even on idle state.

 

[Swamp Rooster]

I am not sure. But why is it building pressure in it's idle state? It should be pumping from the tank, going through the spool and back into the tank with little pressure being developed.

As long as I am not pulling levers it is fine . I can idle it up to 2000 rpm motor / 540 rpm pto... and it is fine.. If I start working the loader it slows my tractor rpm down. If I have a log in the bucket I can kill it if I go to fast .. As soon as I stop moving it is fine..

 

[Industrial Toys]

Restriction (and heat) yes, but not I would think, anything close to stalling the tractor.

EDIT: Just read latest OP response. Thanks, that makes more sense.

I am not sure if messing with the reliefs would fix the problem. Gearing down the input of the pump, or using a better matching pump, or possibly dual stage pump would probably solve the problem. A friend builds hydraulic stuff all the time and is just learning. From what he tells me, you can't get away with nothing. It's all about math and physics.

I have a PTO 2:1, or 1:2 Gearbox from JD for an old tracked JD tractor. That is what I would use, but that doesn't help you.

 

[Swamp Rooster]

Looks like you have a combination of various things creating all kinds of problems.

On the other thread, you mentioned it used a Honda engine with a pump to run the log loader. That pump is probably around 5-6 GPM and the whole hydraulic system of the loader was design around this GPM.

Now, you increased the size of the pump for one that over 2,5 times bigger than the stock one. The rest of the system, as in size of lines and GPM that the valve block can handle was not designed for a pump this big. This will create all kinds of problems. Most likely the stock lines are 3/8", that can't definitely handle this much GPM of the new pump, hence causing restriction even just with the system idling.

Even though you can reduce the system pressure, you're going most likely to still have problems with that pump.

The relief valve is usually on the control valve body.

Not sure what the gpm was on the old pump and motor .. It was a homemade set up ..24 or hp honda or so .. ran belts that ran the pump.. The loader calls for 9 to 11 gpm..

 

[Industrial Toys]

You need so little power. Don't you have remotes?

 

[4570Man]

I think you’ve got way too big a pump for the job required and the hp to drive it. Do a quick google search and find a calculator to determine the HP required for the desired flow and pressure.

 

[Swamp Rooster]

You need so little power. Don't you have remotes?

No remotes on mine .

 

[Swamp Rooster]

I think you’ve got way too big a pump for the job required and the hp to drive it. Do a quick google search and find a calculator to determine the HP required for the desired flow and pressure.

I thought I figured it right and said the pump I have needed 24 hp at max to run it .. I might have done it wrong ..