CAT 320c Hydraulics stalling engine

[Bosvark Kzn]

My CAT 320c (CAT0320CJANB03733) stalls the engine when curling the bucket in and out, also on boom up it stalls when the boom reach full up position and I don't let go of the joystick immediately (even on full throttle). It travels perfectly, no problems.

I have replaced all fuel lines, removed and cleaned the fuel tank, new fuel filters and checked the small screen in the banjo. Fuses all good, wiring on the PRV solenoid looks good, the engine speed sensor is clean. Disconnecting the PRV solenoid makes no difference. The toggle switch under the rhs armrest is in the AUTO position, but makes no difference if in the MANUAL position.

I haven't checked any oil pressures as I don't have the correct gauges and I haven't checked/tested anything electrical with a ohm/volt meter. The original throttle control has been removed and a manual hand throttle installed. Could this possibly affect the PRV operation?

I found the following fault codes today, but don't know what it means.

Active:
69: 587-03

Logged:
69: 600-04
69: 96-03
69: 587-03
69: 587-04
69: 587-08
69: 374-05
69: 376-05
69: 581-05
69: 600-10
69: 110-10
69: 190-10
69: 167-08
69: 190-08
69: 168-05
69: 588-12
69: 254-12

I'm not sure what to check/test and will appreciate advise on how to rectify the problem.

 

[Dapperdan16]

Did it just start doing this all the sudden, or were there warning signs, like started slowly and gradually got worse?

 

[Mark250]

the active code 69 is for the engine /pump controller in relation to the feed back sensor 587 for the governor actuator. relating to a high voltage 03 (usually means open circuit)
Mark

 

[Bosvark Kzn]

Did it just start doing this all the sudden, or were there warning signs, like started slowly and gradually got worse?

Dapperdan16, thanks for the reply. To answer your question:I don't know, I bought the machine as a non-runner, it stood vandalized for about 8 or 9 months before I bought it. It had mostly cosmetic damage and missing one track, so I refurbished it and fitted a timber grapple, it worked for 3 months with the timber grapple. During this 3 month period, we had fuel problems as it had dirt in the tank, so it would often stall etc. I thought it's because of the dirt in the fuel tank. After 3 months we fitted the standard bucket and that's when I really noticed how bad the stalling problem is, so that's when I did and checked the stuff mentioned in the first post.

 

[Bosvark Kzn]

the active code 69 is for the engine /pump controller in relation to the feed back sensor 587 for the governor actuator. relating to a high voltage 03 (usually means open circuit)
Mark

Thanks Mark, so connecting the plug on the throttle unit, should clear that up, the throttle unit is currently unplugged as we're running the machine with a hand throttle.

 

[Ishq]

sudden stalls are always due to bad prv. you need to check the prv pressure to confirm. it may not be working. (as you have a manual throttle, it will not work. ) But if the switch is in manual, then not to worry about the throttle motor. Just change the prv if you have another machine.

There is one more possiblity. If the pump pressures are shown then do this check. Without operating any levers, just check if the unload pressure rises upto 50bars or more then that control most be rebuild. Normally its the internal O-rings which are damaged and then you can adjust them.