Hey all, We have a Pc220-5 that has developed a problem with boom operation, whilst operating the machine whether it be lifting boom rotating bucket swing side to side or extent and retract, the machine bogs right down. Doesn't seem to have affected track operation. Have checked all basics like fuel air ect but we are leaning towards the hydraulic systemm machine shows codes 25 and 80, any help would be awesome. Cheers
The 25 code that you state is either S2 or actually 25. If it is a 25 code that is pressure sensor power source system. That system basically just tells the computer when to shift travel from high range to low range so probably not your issue. There is no 80 code so I am assuming that it is an 08 code. The 08 code is a short in the TVC solenoid system 1. This controls pump torque absorption which could over load your engine and cause the problem you describe. The solenoid is on the pump and the wiring that attaches to it is a common problem. Lots of times the muffler gets a hole in it and cooks the insulation and the wires end up breaking or the solenoid dies. Wiring in your machine is likely thirty years old or more so I would suspect that. Have you checked the screen in the banjo bolt on the suction side of the priming pump? That might be an easier fix.
Hey mate, thanks for the quick response, we will check the things suggested and let you know, as for the banjo screen not sure we have checked that but will also. Cheers
Hey mate, we have a wire problem, is that solenoid you were saying on the lh side of the machine where the airbox is ontop of the pump, and where do the wires go to and from and does this power other solenoids, would you have a diagram of the set-up. Cheers mate
The codes are definitely 08 and s2, when there's no code we have 15-16v at the solenoid on both sides if it's the same one we are speaking about, when the code 08 come on there's no voltage at the solenoid. I'll upload a picture of the one we think its is and how the previous owner has wired it up
You have it correct. That is the TVC or torque variable control solenoid. When the connection is lost between the computer and that solenoid, the pump goes to max and that little engine just can't carry that kind of load. You photos show what I normally see in one of those machines. The insulation gets hard and cracks and wires get broken. That harness as I recall goes into the engine harness in the middle of the engine compartment and then through the machine frame to the cab. Good Luck!
Do both of them wires from the solenoid go to the cab mate ? And do they go to the computer or control panel ?
Both wires go to the pump control computer in the cab. Both the throttle control computer and the pump control computer are behind the panel that holds the mirrors. I think you have a glove box on top of the computers that is under a tilt up door or cover. There should be two toggle switches in there. One is a swing brake bypass switch and the other is a TVC Prolux, Komatsu term, or bypass. If you throw that switch you would normally have voltage at the solenoid valve all the time. I've done that in the past to check the wires. I'll throw the switch and go back there and move wires around to see if the voltage goes away as the wires are moved.
Hey mate, still havnt sorted it out, could you tell me what voltage there's meant to be at the solenoid with the switch flicked on and off. One wire goes to the computer, where does the other go too ? And what voltage does it read or is it a earth ?
Both legs of that wire go to the TVC Prolix switch in the cab. There are six wires total going into that switch. There are two TVC connection pins in the pump control computer. They are number 9 and number 17 on computer connection C1. Basically I'm not sure you can measure voltage at the TVC solenoid connection. The positive power comes from #9 pin in the computer and the negative side is the ground which is inside the computer through pin #17. What you might be able to do is disconnect the C1 harness from the computer and use an ohm meter to check for continuity to ground on Pin#9 of the harness connector and the same in the pin on the computer. It might be easier to just trace the harness wires from the TVC solenoid back along the machine frame.