No pressure on auxiliary hydraulics on U35-4 excavator

[Megawampum]

Hello, I just recently joined this forum. I have a 2019 U35-4 with an angled blade and about 1000 hours.

I recently installed a thumb, and when I went to test it, I discovered that I was only getting 25psi via the auxiliary discharge valve instead of around 3000psi.

I spoke to a Kubota service guy and if I understood him correctly, he mentioned that it is likely that an electrical connection on the solenoid related to the pilot controls popped loose and it needs to be reconnected.

First of all, does this make sense? If so, where would I find this disconnected wire?

I have both aux valves set to max psi for testing purposes.

Here’s what currently happens when I try to move the thumb:

If the thumb is closed, I can open it with the rocker switch no problem. If the thumb is open, I click on the rocker switch and it sounds like it’s trying to close, but the only way to get it to close is to shake the boom or arm a bunch until it slides open.

Any thoughts would be appreciated.

Thanks in advance.

 

[whitetiger]

Check the selector valve under the RH access cover. It may be turned to the single-action rather than the double-action position.
There should be a decal next to the silver handle showing which position is which.