Komatsu excavator PC 350LC-8

[idss]

Hi guys, I am working on Komatsu PC350LC-8, don't have the serial numbed, the plate missing , The machine is not moving, the operator said it just stopped. I removed the hose from the P port on the solenoid valve block , now oil flow out, I switched the operation to manual
with the switch behind the seat , still nothing, I don't have much experience with Komatsu excavators, hope you guys can help, again

 

[funwithfuel]

Does the engine run, is there oil in the machine? Do you have gauges? Have you viewed JohnC youtube channel describing how to access your service menu?
Gotta give a little to get a little. Need more to go on than "just stopped " what stopped? Machine, engine, travel, hydraulic functions?

 

[LACHAU]

Hi guys, I am working on Komatsu PC350LC-8, don't have the serial numbed, the plate missing , The machine is not moving, the operator said it just stopped. I removed the hose from the P port on the solenoid valve block , now oil flow out, I switched the operation to manual
with the switch behind the seat , still nothing, I don't have much experience with Komatsu excavators, hope you guys can help, again

Does the engine run, is there oil in the machine? Do you have gauges? Have you viewed JohnC youtube channel describing how to access your service menu?
Gotta give a little to get a little. Need more to go on than "just stopped " what stopped? Machine, engine, travel, hydraulic functions?

I have the same question as "Funwithfuel".
I assume you mean the machine's hydraulic system doesn't work at all, right?

 

[LACHAU]

I assume you mean the machine's hydraulic system doesn't work at all, right?
if yes, I suggest you check the output of "Locking primary press PPC solenoid valve" (the other name is PPC hydraulic pressure lock).

 

[idss]

Sorry, the engine is running fine , there is oil in the hydraulic tank ,about 3/4 full. I have several gauges to check the pressure. I will have a look at the video, and thanks for the diagram, do you have a diagram that shows the input and output connections location on the hydraulic pump?

 

[funwithfuel]

Don't jump straight to the pump. It's highly unlikely, that is the cause. If you've lost all functions, odds are, it's the safety solenoid which LACHAU has pointed you to.

 

[funwithfuel]

On the solenoid tree, the magnets are all the same. The one on the end closest to the silver/gold ball, that will be the safety. You can check the plug V01 for voltage with the safety flag raised. If you have voltage, swap the magnet with either V07 or V04. Better to sacrifice high speed travel or the option circuit in the interest of "getting going"
When swapping magnets, beneath each mag is a tiny little spool that may try to slide out on you. Be ready and be careful. In the off chance that your accumulator actually works, you may get a gush of pressurized oil approximately half a liter. Good luck.

 

[idss]

I will check that solenoid and let you know, and switch the coil if there is voltage there. One question , from the diagram you sent , should port P have pilot pressure? and it looks like the oil pass through a nonreturn, then to the lock solenoid, and there is no pressure at P. This is why I thought of the pump.

 

[LACHAU]

Sorry, the engine is running fine , there is oil in the hydraulic tank ,about 3/4 full. I have several gauges to check the pressure. I will have a look at the video, and thanks for the diagram, do you have a diagram that shows the input and output connections location on the hydraulic pump?

Please see attached file.

 

[idss]

Thanks Lachau, I am going out to the machine today and I will make the checks the you recommended, and make the coil switch if necessary.

 

[idss]

Hi guys, I was at the machine, I checked the voltage for the pressure lock solenoid , there is 24 volts when the safety lever is raised, but the coil was open, so I swapped it with V2, and nothing happened.
So I went and checked the fault codes in the display and found the codes below.
01/08 CA559 rail pressure low,
02/08 CA272 IMV/PCV/ open error,
03/08 DA2RMC CAN discon, pump con detected,
04/08 CAN discon monitor detected,
05/08 CA428 water in fuel,
06/08 DXAOKO PC EPC sol open,
07/08 DXEOKO LS EPC sol open
08/08 2 stage relief sol open

 

[idss]

I could not remove the hose at A1 to check ,did not have the tools and don't know to disconnect it

 

[funwithfuel]

On your display, adjacent to the error codes should also show first and last time triggered. Right now let's focus on what is current.
By the way, the serial number should be stamped in the frame between the boom cylinders or on the boom side of cab platform . Hope this helps.

 

[max s]

I would take a look at the pilot pressure which is generated by the self pressure reducing valve. This valve takes the pressure from the main pump P2 and regulate it down to 3.2 Mpa to provide pilot pressure. You can check pilot pressure on the main control valve, see picture.

If you have very low pressure the valve will need to be changed but sometimes a good cleaning and new o-rings are enough to make it work again.

Hope this helps

 

[idss]

Thanks Max s, ok, I will check the pilot pressure and let you know

 

[idss]

Hi guys, I got to the machine , and decided to remove the self reducing valve and clean and serviced it , it had all kinds of particles and debris inside. after I replaced it, the machine started working , so we were able to
move it form the hill side , to a flat ,area to continue work on the electrics,
Thanks again to you guys, and Thanks Max s , it was the pilot pressure valve, I will recommend a new replacement.

 

[max s]

Glad that I could help !