daewoo 220 lc two speed

[ironman1953]

just purchased a Daewoo Solar 220LC excavator on an estate sale , not much history available , machine seems to be in very good shape , not much wear on anything , only problem machine travel speed is in high range and I cant figure out how to get it to shift to low speed , low/high switch on console is ineffective, switch has voltage and seems to be working , tracked wiring down and everything seems to be fine ,checked case drain on drive motors , seems OK , but not familiar on how system is suppose to work , how does hydraulic system divert oil to make drive motors run at a slower rate of speed

 

[uffex]

Good day
See attached.
Kind regards
Uffex

 

[ironman1953]

we know about the switch , it seems to function correctly , has power to it , we know the drive motors are OK because we can disconnect the piolot press hose and excavator operates in low speed , somewhere in the piolot pressure hydraulic circuit there must be a valve or mechanism that switches it on and off

 

[uffex]

Good day
I have taken a look at the Solar 225 hydraulic schematic illustrating a solenoid valve which controls crawler high speed. The valve is in a bank of three at the very end. I cannot be sure that the 220 is the same but if you take a look at the central joint and follow the small line this will lead to that valve. Post a photo of the central joint & hydraulic schematic if you need some further assistance.
Kind regards
Uffex

 

[ironman1953]

center swival , line on ride side is a grease line

 

[ironman1953]

travel foot valve on floor of cab

 

[ironman1953]

hoses from travel foot valve go to this junction block

 

[ironman1953]

from junction valve , lines go to this 3 solenoid valve assy

 

[ironman1953]

hyd line from center swival connects to center hose of the 3 hoses shown,, on this 2nd 3 soilanoid valve

 

[uffex]

Good day
That is the correct solenoid you have located, a wiring schematic would be very helpful however I guess you do not have one.I suggest you as a first switch on & off see if you can feel or hear any movement > check to see if you have any power & ground > try jumping with a power and ground see if it works. If not you are looking at the solenoid as a fix.
Kind regards
Uffex

 

[ironman1953]

thank you ,we do have a service manual , with some wiring diagrams , we now have realized we are in the right area now , but now another thing that makes this harder to figure out , this machine has this EPOS computer control system on it , and all the wires from these solenoids and switches first go to the EPOS controller , so we are not sure how that comes into play

 

[ironman1953]

more wiring diagrams

 

[uffex]

Good day Ironman
Those are not so helpful, are there any complete electric & hydraulic schematics in that manual you can post. I can then try and make sense of the machine.
Kind regards
Uffex

 

[ironman1953]

those wiring diagrams are as good as it gets in this manual , but we did get it to work , my technician who is very resourceful , though we never really found the problem,, He figured out a way to wire in an extra little harness to trick the low pressure system into diverting the oil away from the valve when the switch was turned to the low drive position , so thanks for all your help , let me know if you need any help in the future , thanks Brian

 

[uffex]

Good day Brian
Great you are out of trouble thanks for keeping us in the loop.
KInd regards
Uffex