I've got a 1997 Cat 311B 8HR00794 (I use the 8GR when looking for parts) that I've had for about 6 months before it started lacking hydraulic power. Curling the bucket or lifting the stick will stall out the engine if you aren't careful. Everything worked great before but now this is slowing us down. I've tried checking the voltages in normal and backup mode on the PRV connector, nothing changes. As a side note, the swivel lock is engaged in normal mode so we have been running it on backup so we can keep working. Does anyone have the voltage specs on the solenoid or ideas of what to look for next?
hi, As i know PRV solenoid resistance should be with in 9-15 ohms. voltage should be 6-9 Volts in normal mode(backup sw @ auto position) when all control levers are in neutral position. when control lever operates voltage goes down. These voltages should be checked between two wires without disconnecting prv solenoid.
if the ' implement/swing pressure switch ' is bad then this problem will happen. check whether is it working properly.
I couldn't mention earlier, these specs are for a 8GR, but i think, this same specs will match with 8HR as well.