PC210LC -8 Losses pilot pressure

I have a PC210-8 that's new to me; the machine has just over 7,000 hours. I've put about 30 hrs on it so far. After about an hour and a half of running, if I stop moving the controls for a few seconds, I'm unable to get anything to work/move on the machine. It's like putting the safety down. I have tried putting the safety down and back up, adjusting the throttle, etc. At times, I can get the hyd thumb to move, and this will increase the pressure from both pumps enough that everything starts working again. There have been a few times that nothing seems to help the situation, so I shut the machine off, start it back up, and it will work fine for another hour or longer. Engine temp and hydraulic temp are well within normal range. I've watched the pressures from the pumps, and they seem to be in normal ranges. The solenoids seem to have the correct pressures and voltages when working. When the machine malfunctions, there is little to no pressure on the pilot system, and the solenoid voltage remains unchanged. I'm still figuring this machine out, and I've read through a lot of the operator's manual and the service manual, but I could be missing a setting somewhere?? One other issue is that the auto idle function doesn't work. I'm unsure if the two problems are related. I'm thinking it has to be a valve or electrical problem somewhere close to the pump that's affecting everything in the system. I've searched through this forum for similar issues, but didn't see anything. Any help is greatly appreciated.

Not providing any help but I am onto something like this.... PC220LC-8 30-45min and I lose pilot pressure but standby on rear pump stays. I work in a used machine ''dealership'' and started on that problem in 2023.... worked on that for about a year and the machine was parked in the corner of the yard. Dusting off some anchors and I'm back at it... I have replaced the pressure reducing valve - no effect (even tried the old one on another machine... never gave up) I have adjusted standby pressure higher and lower - no effect I have played with LS pressure - no effect I have played with PC pressure - no effect I have replace all the solenoid valve on the merge/divider and pump - no effect (probably tossed the old one between then and now...) I have created more problems on the machine than repairing it.... now were trying to fin the whole merge/divider valve on the control valve (used) with little success... Right now I'm trying to recover the functionality of the machine but it seems my merge/divider is defective..... maybe the jubber solenoid. The pump seem to be merged at all time. I will try to keep you informed if i get any success

I recently got my machine working within specs. Things found, the very small o-ring on the sleeve for the low pressure side of both main relief valves were cut/broken. I replaced those along with the other o-rings. I used lapping compound and a drill and slowly lapped the small plunger and seat to clear out some wear. This got the MRV working great. I pulled the self reducing valve, pulled it apart, cleaned everything up and lightly polished the spool, that helped it to work better. The MRV's were my biggest problem. I've adjusted the pressure to the low side of specs and everything is working much better.

No more loss of pilot pressure? I did remove the pressure reducing valve at one point and polish the spool as well but lost it again and again. We replaced the pressure reducing block afterwards and no change. MRV's were adjusted at one point because we were out of idea's.... Didn't check on the o-ring's. might try and see. For now I am looking at my merge/divider problem first (no pressure on top of the spool) and will be onto the losing pilot after.

If you loosen the lockout, takes a 30mm wrench, unscrew that half of the mrv out, that's the low pressure side. It will have the small rod and spring. Inside of that is a small sleeve with an o-ring, if that o-ring is cut it won't build much pressure. I'm at work now, if you need a diagram, I can send one when I get home.

Relief valve or unloader valve?

Relief, I don't think you can adjust the unloader.

Just a thought, have you tried swapping your safety solenoid with the option solenoid? The magnets will fail,the pin will stick sometimes the mice eat the wires.

yes it was the first thing that we tried

Just curious, do you have the service manual? The first thing it shows in troubleshooting is the main relief valve. It seems you've jumped all over, that can cause a lot of other issues.

I do have a service manual but what I have is : troubleshooting H-3 work equipment, swing and travel system do not work -malfunction of ppc lock solenoid valve -malfunction of self reducing valve -defective piston pump -defective damper But I will definitely check that MRV when I'm done with the merge/divider

OK good, check out H-1, you can pull the pressure chart from section 2, I believe. Here's a video that might help.

Very interesting! I will see what these o-ring look like!

Just a question about codes on the dash. Is there any, Southerman had a whole bunch of codes on his and it was all connection problems, corrosion, oil in connectors. He cleaned up and even his Auto -idle came back on line. Do you have schematics for it. Simon C

Yes I do have electrical schematics. No codes present, only lost of pilot pressure. I will have to check again since it's been 2 years that I worked on it.... Currently on something else but I will eventually give it go again

Start capping pilot liens off and see if it gains back, I've had bypassing attachment pedals, travel leavers etc bleeding off pressure