bypass problem

[paul bernier]

Hi, I am a new member and I have a problem with 4150 Kubota tractor with a loader. The thing won't quite lift the grape bins I am loading. I want to raise the pressure to the loader just a little. So my question is when there are 3 pressure relief valves in a series system, and the loader valve is #2, can the upstream relief valve affect the loader pressures? Paul

 

[J_J]

If your first relief valve is set at 2600 and the second relief valve is set to 3000 psi, the first relief valve will limit the pressure to the second.
If you have several relief valves, they should all be set the same.

Actually, with the second valve mounted in the system, you could not adjust the second relief valve to 3000 because the first relief would limit the available pressure.

Yes, if the first relief valve is set at 2500, that will regulate the rest of the system.

You might have to set the second or third relief lower to protect just that circuit. For instance a log splitter on the 3pt. The log splitter valve relief could be set to 2300 psi to protect just the log splitter. That would pressurized everything up stream to 2300 psi.

On the first valve, install a pressure gage in the IN port with a tee. Then check the pressure on the first valve. Then activate the levers on the second valve and adjust the second to match the first valve.

 

[paul bernier]

Thanks JJ, I am going to try that today, Paul

 

[paul bernier]

JJ,I got into it today with a pressure guage, and got 2400lbs at the3pt cylinder head, where the manual says to check. I put another shim behind the pressure relief valve which I calculated would raise the pressure 160lbs. I got the same reading, and started to think I needed a new pump,$1300 and 6 weeks wait, I found out by phoning around. I thought maybe the circuit doesn't run the way I think it does, so I checked the other end, after it passes thru the loader valves and a 3 spool valve for a box scraper. I just adapted the guage to a male quick connect and plugged it into the system, and started the motor. I got 2710lbs. The manual says max is 2560lbs so I took out the shim I had put into the pr valve, and set the adjustable valve on the 3 spool bank to 2560lbs. Problem cured. Thanks for your help. Paul