I have a 1997 Daewoo Solar 220LC III excavator with a dead short in the safety cut-off circuit. I have the parts catalog but can find no reference to the cut-off solenoid. Can anyone tell me exactly where on the machine the solenoid is located? Thank you.
On most machines: Follow the line out of your pilot pump (small gear pump probably mounted on the back of the main pump), it probably goes through a medium/high pressure filter. There might be a couple of lines teeing off it, eventually you should come to a block with a solonoid on it, that should be the dump valve for the pilot circuit. If you post a picture of the pump area, I might be able to pick it out.
Do you see any Electrical WIring on or about the circuit? If so, trace it to the solenoid valve.
However, the seat "Switch"could be an Air or Hydraulic 3-Way valve that applies Pilot Pressure o a Plot Operated Safety valve.
And, the switch could be actuaed by the Seat Belt since that is part of the Operator safety setup.
Bud Trinkel FP Consultant Retired "It is incumbent on every generation to pay its own debts as it goes. A principle which if acted on would save one-half the wars of the world. "Thomas Jefferson"
I traced the line from the high pressure filter forward to a distribution block with three solenoids on it. The short is in the first of the three. Can I replace just the one electrical solenoid without disconnecting the hydraulic lines, or must the whole block be replaced?
yes, you can replace just the solenoid... if it is damaged...it is not difficult...
if you can post a hydraulic circuit, then it would be easier to analyze the possible problem that may occur... if these solenoids/valve are very small and connected(small tubes) to either a relief valve(as vent) or to the pump's "x" port... then it can be said as "main pressure"(to initiate a flow to circuits) control valves...
This message has been edited. Last edited by: maglub,
Maglub Active Hydraulic Clown
Posts: 416 | Location: Rise of Nations Thrones & Patriots/NY | Registered: 12 November 2008
Usually the safety solenoid valve is just an "off/on" normally closed valve if you need to get it running until your solenoid arrives remove the valve body and undo the spool so it is only manifold for oil to pass freely through it, but remember to replace faulty component ASAP and inform operator/s of modification.
Posts: 101 | Location: Australia | Registered: 01 September 2007
Removing the cartridge portion of a dump valve will leave it in a "dumped" state, pilot pressure will not develope and nothing will fucntion. Check the resistance reading of the first coil and compare it to the two other coils. If it's a 12 volt system, they should be somewhere around 19 to 40 ohms, depending on the wattage (power) of the coil. You could swap the coils just to get going. follow the lines out from the other solonoid valves, if one goes through the rotary manifold of the machine, that will be the two speed pilot signal for the propel motors, if they go up to the main pumps, they will be power range selectors for the pump controllers.
Doug, Just right. I looked at the schematic of the cut-off hydraulic block and removing the spool would leave the bypass back to the tank wide open. The system is 24V. I'm quite sure the first of the three electromagnets is shorted out. Leave it connected and I blow the 10amp fuse, unplug it and I don't. I ordered a new electric solenoid this morning. Should be in by Thursday. Thanks again to everyone for your help. Jim Stepp South Casco, Maine
Fluid Power Forums 
