bumperm
Veteran Member
The service manual spec for the relief valve on my Kubota B3350 is a max pressure of 2450 psi. I added shims to adjust from 2050 (as delivered) to 2500 psi. This measures the same at both front loader quick connect and at backhoe power beyond. When a control is held open and a cylinder goes to end of travel, the gauge goes to 2500 and stops, okay, but if control input is still held, as one might do when using the backhoe pulling on root etc, the pressure then creeps up towards 3,000 psi. It does this on both FEL and BH, and with two different test gauges.
My guess is that the relief valve isn't passing enough volume of fluid for some reason, and that this is then allowing the pressure to creep up. Has anyone else experienced this or know of a fix? For now I'm just making sure I don't hold a control open at a stop or maxed out for long.
My guess is that the relief valve isn't passing enough volume of fluid for some reason, and that this is then allowing the pressure to creep up. Has anyone else experienced this or know of a fix? For now I'm just making sure I don't hold a control open at a stop or maxed out for long.
