Hello, I could really use some troubleshooting help. I've got this JD 310SG that uses this electrohydraulic system. Every time I bump the hoe bucket on a rock or hard material it shuts off. I have to keep flipping the pilot control switch off and on again. I've replaced the pilot switch, the solenoid in by the fuses, and recently I replaced the solenoid on the backhoe valve body. It hasn't resolved the problem. If anyone has any suggestions on what this might be please let me know I would greatly appreciate it.
Many electro-hydraulic systems have a pressure switch that kills the pilot circuit if pressure exceeds limits (protects the system). If it's set too low, failing, or has a bad connection, shock loads trip it. Look near the main valve or pump. Some JD models have load-management programming that cuts pilot power on over-pressure events. Check for stored fault codes too.
Welcome to HEF briach01 ! Please provide the machine's complete serial number. A faulty seat switch can knock your backhoe hydraulics out. The seat switch function can be seen in the monitor. That is why I need the serial number. To get you some accurate information on how to do that. I assume the loader is still working? Those machines have a history of relief valve issues that can cause the hydraulics to quit. Again, serial number dependent on whether you lose loader functions or not. You said you replaced a solenoid on the backhoe valve body? The solenoid for the pilot controls are on the pilot manifold, which is mounted on the forward side of the backhoe control valve.
Thank you. The serial number is: T0310SG961276. My monitor is an older one that doesn't show much information but I will try to look through the codes. The loader works fine, it's the hoe that cuts out. I just replaced #13 AT174923(above). Did not have any effect on the problem. I just ordered: KV25678(#8 below) another solenoid valve that's on the pilot control manifold(ST160647), I should get that in a week or two. The faulty seat switch is interesting, didn't think of that I'll do some testing today. As far as the pressure switch goes I read in another post that it's possible on the pilot control manifold there's a pressure reducing valve that may get contaminated. See below.
It should show the seat switches when in Service Mode. Check your messages. Solenoid #13 above in the first picture is for the auxiliary hydraulics.
I went into the display Service Mode and went through all the options/settings/diagnostics and what not. No codes or saved codes. Nada, clear, everything looked to spec. So I thought hey let's get scientific about this. I got in the seat turned the backhoe on and jumped up and down. Guess what quit working.... I don't know if I'm mad or happy. But I'm thrilled that you put me on this path, I would have never thought to check the seat sensor. So kudos and have a beer/coffee on me.