Bobcat T 770 High Flow Hydrolic problem

[Bill Jacobsen]

My T770 keeps jumping out of high flow. In the mornings when the hydraulic fluid is cold the high flow runs find and than after about 30 minutes is will jump out of high flow and will not go back in. Time after time and i am running a mulcher head. Does anyone know why it keeps jumping out of high flow once the hydraulic warms up. The hydraulic fluid temperature is at only 100-120 when it jumps back to low flow. Low flow will run all day with no problem. The dealer said i need a whole new wiring harness for 6,000.

 

[Bill Jacobsen]

Does anyone have an idea of what to check?

 

[Bayrat]

There must be a solenoid or microswitch that operates the high flow, check that out. Sometimes when those heat up they can be problematic. Knowing very little about your skid steer wiring but guessing from my own experience with those devices.

 

[Bill Jacobsen]

OK thank you! I will try and find a wiring diagram.

 

[Mbar]

High flow selnoid is on the end of the pump. Take the panel off below the drive motor on the right side. You can check the ohms on the coil. I’m going to guess 10.9 with out looking. Pull the stem out and see what it looks like. The coil will say if it is 12v if so test it in your hand to see if it is sticking. Do not put power to it with it plugged in. I believe the 770 do not have a separate aux relief like the 870. If you need a wire schematic pm me your serial number and email.