Is my pump going/shot?

[logman81]

Had to order a pressure gauge from napa no one had one in stock. Then I'll make up a test gauge with a hydraulic line and a few fittings to test the pressure. I should be able to know exactly what it's doing in the next day or two.

[Corley5]

You could have had a new pump to install in that same time.

[47sawdust]

No harm in verifying the problem before you start.I've replaced quite a few electrical components on my tractor until I got to the real problem.Oh well,I just call it continuing education.
Good luck logman

[logman81]

Yeah no rush saw is in the shop getting diaged it's leaning out for some reason and still waiting for the guy that's buying the wood to come pick a load up so I can get paid to buy the new pump if that's what it is.

[logman81]

Got the pressure gauge made up! 

 

[logman81]

Well guys I pressure tested it this morning.  I plumbed it into one of the work ports that operates the blade.  I only got 1100 psi at the highest. I believe the relief valve is functioning as I can hear a squealing sound from the control valve.  What do think my problem is? Should I try turning in the relief valve to see if I get more pressure? In my opinion that is pretty low pressure for this machine.

[mad murdock]

Is that a single stage pump?  Of so, I would think that you should be up at least 2,000.  If you have a book for it, see what spec is, though a good hydraulic shop should be able to tell you approximately what it should run.

[logman81]

Single stage gear pump on my skidder

[logman81]

No book for this rare skidder,  but yes I do agree I should be minimum of 1500 psi.

[kiko]

Logman, if you hear the relief valve squealing when you get the blade all the way up or down that means your relief valve has opened off the seat at 1100psi.  From here it sounds like you have an issue with the relief valve rather than the pump.   Is the main relief adjustable?

[logman81]

Yes it is adjustable, I've been told to turn it up to 2500 psi.

[logman81]

I'm still not sure that it isn't the pump.

[Corley5]

You haven't tightened the relief yet  ??? :

[logman81]

No not yet, a few people have said that if I do that I risk destroying the pump.

[kiko]

You would risk damage to the pump by jacking the pressure up without a gauge. But you got that now.  Plumb the gauge into the blade up line, lift the blade to its stop, i believe this where you hear the relief squeal ,  note the pressure on the gauge.  You can turn the relief in say a half round and recheck the pressure,  or with an assistant you can turn the relief adjustment in while holding the blade lever in the up position.  if this changes nothing then i would consider checking the orings on the relief valve. Remember that the pump does not create pressure, only flow. Restriction of that flow is what creates the pressure. However the pump must be strong enough to withstand said pressure.  Take up to 2000 psi to begin with and see if that is enough for your needs, i would think 2500 would be the max.  Also does your control valve have port reliefs as well as a main or does just have a main? 

[logman81]

Ok I will do that and see what happens with a helper. It only has the one main relief for the whole system.

[logman81]

Just pulled the pump, it's a splined shaft and it's not striped. It appears to be a pretty standard two bolt gear pump.  I figured just replace it to eliminate that being the problem.  Plus I would like to step up the gpm a little for faster hydraulic cylinder speed.

[logman81]

Well in my opinion the pump internals look ok to me. I think I'll take it to a hydraulic shop and have them examine it to be sure it's ok.

  

  

 

[beenthere]

All that scoring on both parts doesn't look a bit excessive to you?

Maybe a filter wasn't doing its job ?? just wondering....

[logman81]

I'm not sure how excessive it is or what's tolerable. I don't have a filter that I can find in the system.

[logman81]

 

  

 

[kiko]

I still dont think that is all the problem, but that pump looks like is toast to me. Gouges especially in the center where the gears meet will connect the suction and discharge side, and  will cause pressure loss.  i would think about installing a filter in the return line prior to tank.

[Corley5]

That pump's shot.  Save your money don't bother taking it to a shop.  Take your relief valve there instead and have it checked and resealed.  Order a new pump from Surplus Center.  A hydraulic shop typically can't beat their prices.

[logman81]

Yeah time for a new one, hopefully that solves the problem!

[OntarioAl]

logman81
Your system is contaminated with particles of crud, Do like kiko suggests and install a return line filter. You might seriously consider draining and flushing your transmission and  new oil.
Al