Backhoe Does RPM effect PSI to backhoe or just speed?

[J_J]

With a perfect hyd pump, you would have high pressure as soon as the pump was turning.

A worn pump will leak, and increased rpm will compensate for some of that loss.

GPM/volume will dictate speed of operation.

You can reduce the engine rpm for less GPM of fluid, or run the engine at max and add restrictors in the BH circuit. A needle valve will adjust the flow as you desire.

If your BH is the first valve in the series flow, then it becomes the master relief, and you can set the relief pressure for tractor specs.

 

[L355SS]

I would first check the fluid level in your reservour for your pto driven pump.
Dennis

 

[SPYDERLK]

With a perfect hyd pump, you would have high pressure as soon as the pump was turning.

A worn pump will leak, and increased rpm will compensate for some of that loss.

GPM/volume will dictate speed of operation.

You can reduce the engine rpm for less GPM of fluid, or run the engine at max and add restrictors in the BH circuit. A needle valve will adjust the flow as you desire.

If your BH is the first valve in the series flow, then it becomes the master relief, and you can set the relief pressure for tractor specs.

To expand on what JJ said: Pumps all leak some internally. When they encounter back pressure they leak more. When the fluid is hot/less viscous they leak more. Combine hot fluid and low rpm and it is quite likely the pump will leak enuf that it wont deliver the relief pressure. Add a worn pump and you can be sure that it wont. Rev it up and youll overcome the leakage and have full pressure.
larry

 

[Gary Fowler]

This little discussion backs up my belief that my B26 pump is fine, just relief valve setting needs adjusting. The pressure is the same at idle as at WOT so I think the pump is fine since the pressure doesn't decrease or increase with throttle position.