Slow FEL and 3Ph

[Jake9000]

There are two outlet ports.

Tank port goes straight to reservoir and does noy normally carry oil.

PB is where the center flow exits and goes to 3rd function. You just checked that port and said no flow.

Dan

Ok. So then I just checked the tank port. Sorry this is kind of foreign to me. I will check the PB port for flow and pressure

 

[TheOldHokie]

Ok. So then I just checked the tank port. Sorry this is kind of foreign to me. I will check the PB port for flow and pressure

There should be no flow on the tank port. If you had flow you gave found a problem. I ft may not bd the only one. Check for flow and pressure at PB. Check pressure at both idle and max rpm

 

[Jake9000]

There should be no flow on the tank port. If you had flow you gave found a problem. I ft may not bd the only one. Check for flow and pressure at PB. Check pressure at both idle and max rpm

I have flow at idle on the PB port. However I have no pressure at idle or max RPM with the lift deadheaded.

 

[TheOldHokie]

I have flow at idle on the PB port. However I have no pressure at idle or max RPM with the lift deadheaded.

By lift you mean loader?

Dan

 

[Jake9000]

By lift you mean loader?

Dan

correct.

I have flow at idle on the PB port. However I have no pressure at idle or max RPM with the lift deadheaded.

correct. I don’t have any pressure at any time at any rpm. Not even with the loader completely raised and deadheaded at max rpm.

 

[TheOldHokie]

correct.


correct. I don’t have any pressure at any time at any rpm. Not even with the loader completely raised and deadheaded at max rpm.

The loader can never cause pressure on the outlet port.

You have oil flow on the tank port with loader in neutral and no downstream pressure.

That means the relief valve is never closing which explains the loss of hydraulic power and flow. Its a cartridge valve and not serviceable. A replacement cartridge is $200 from Messicks.

Dan

 

[Jake9000]

The loader can never cause pressure on the outlet port.

You have oil flow on the tank port with loader in neutral and no downstream pressure.

That means the relief valve is never closing which explains the loss of hydraulic power and flow. Its a cartridge valve and not serviceable. A replacement cartridge is $200 from Messicks.

Dan

I just want to make sure that we are on the same page. I have flow at the PB port at idle.

There is not really any flow through the tank port at idle with the loader valve in neutral. I would say it was just residual in the line leaking out while the hose was unhooked. However at max rpm’s with the loader valve deadheaded in the lift position there was flow out of the tank port.

Are you still saying that the pressure relief valve is the problem?

 

[TheOldHokie]

I just want to make sure that we are on the same page. I have flow at the PB port at idle.

There is not really any flow through the tank port at idle with the loader valve in neutral. I would say it was just residual in the line leaking out while the hose was unhooked. However at max rpm’s with the loader valve deadheaded in the lift position there was flow out of the tank port.

AAre you still saying that the pressure s valve is the problem?

RPM does not matter - all that does is increase the rate of pump flow. There should be ZERO flow out the tank port at pressures below 2800 PSI. All the flow shoukd be going out PB.

Put your gauge back on the inlet port and deadhead the loader . First time around you got 400 PSI at idle because all that flow was going out the tank port. You can see that with the tank port disconnected which means the relief is open at 400 PSI.

At max RPM you got it up to 1500 PSI because the increased flow was increasing the pressure drop acriss the relief. You can see that flow increase with the tank port disconnected.

So YES, we KNOW the pressure relief is malfunctioning.

Dan


.

 

[Jake9000]

RPM does not matter - all that does is increase the rate of pump flow. There should be ZERO flow out the tank port at pressures below 2800 PSI. All the flow shoukd be going out PB.

Put your gauge back on the inlet port and deadhead the loader . First time around you got 400 PSI at idle because all that flow was going out the relief. You can see that with the tank port disconnected .

At max RPM you got it up to 1500 PSI because the increased flow was increasing the pressure drop acriss the relief. You can see that fliw increase with the tank port disconnected.

Dan


.

Ok thanks. Will the new relief valve need to be set at the specified pressure or will it be preset?

 

[TheOldHokie]

Ok thanks. Will the new relief valve need to be set at the specified pressure or will it be preset?

That I dont know. Consult your workshop manual. If the cartridge is adjustable try adjusting the old valve befire scrapping it. If you get a new one AND its adjustable you test and set it just like we did here.

Dan

 

[Jake9000]

That I dont know. Consult your workshop manual. If the cartridge is adjustable try adjusting the old valve befire scrapping it. If you get a new one AND its adjustable you test and set it just like we did here.

Dan

Thanks. Yes it is adjustable. I have tried adjusting it with no changes.

 

[TheOldHokie]

Thanks. Yes it is adjustable. I have tried adjusting it with no changes.

Double check the flow out tank. Thats how you know your low pressure is caused by the relief and not the pump.

Dan

 

[Jake9000]

Double check the flow out tank. Thats how you know your low pressure is caused by the relief and not the pump.

Dan

I double checked the tank port it had flow again when I dead headed it at max rpm’s. So I put in a bran new pressure relief valve for the loader. This stopped the flow out of the tank port at max rpm’s. However at an idle if I try to raise the loader I only get 350-400 psi on the loader inlet valve. At max rpm’s dead headed on the loader lift I get 1800 psi.

 

[TheOldHokie]

I double checked the tank port it had flow again when I dead headed it at max rpm’s. So I put in a bran new pressure relief valve for the loader. This stopped the flow out of the tank port at max rpm’s. However at an idle if I try to raise the loader I only get 350-400 psi on the loader inlet valve. At max rpm’s dead headed on the loader lift I get 1800 psi.

Dang! Inlet pressure went from 1500 to 1800 PSI. If you are sure there is no tank flow that points a finger at the pump. Did this problem come on suddenly?

The next step would be a direct test of the pump.

Dan

 

[Jake9000]

Dang! Inlet pressure went from 1500 to 1800 PSI. If you are sure there is no tank flow that points a finger at the pump. Did this problem come on suddenly?

The next step eould be a direct test of the pump.

Dan

The problem did come on suddenly.

Ok then I will get the pump tested next. Hopefully I can get it to the dealer next week so they can test it. Thank you very much. I will let you know how I make out when it happens.

 

[TheOldHokie]

One more test. Connect the gauge directly to the PB port. No tee, we want to deadhead the pump.

Dan

 

[Jake9000]

One more test. Connect the gauge directly to the PB port. No tee, we want to deadhead the pump.

Dan

I got 300psi at idle and 1500psi at max rpm

 

[TheOldHokie]

I got 300psi at idle and 1500psi at max rpm

Your numbers are floating all over.

You can do the pump test your self if you dont want to wait on the dealer.

 

[Jake9000]

Your numbers are floating all over.

You can do the pump test your self if you dont want to wait on the dealer.

that’s what I said as I saw them.

I’m not sure how to test the pump or if I have the fittings to do so. I’d rather do it myself.

 

[TheOldHokie]

that’s what I said as I saw them.

I’m not sure how to test the pump or if I have the fittings to do so. I’d rather do it myself.

Same setup as you had on the inlet but put a valve between the tee and the port. See pucture below.

Open the valve, start the tractor, snd observe pressure as you gradually close the valve. If the pump is working you will get to 2500 PSI before the valve is fully closed.

Dan