kobelco sk 100 hydraulic problem

[dirtdigger123]

I've owned this sk100 for 8 years the track motors allways were slow unless u flip the kpps switch this turns the computer off or bypasses it I think. Well after a while I got use to it then one day the bucket. Arm and swing got slow. After a little use noticed if u pull back on the right joystick while swinging speed was fast or normal also if u set 1 foot on travel pedal and press lightly while swinging speed is normal. Any one know anything about kobelcos with the kpps test switch

 

[wgwestervelt]

I've owned this sk100 for 8 years the track motors allways were slow unless u flip the kpps switch this turns the computer off or bypasses it I think. Well after a while I got use to it then one day the bucket. Arm and swing got slow. After a little use noticed if u pull back on the right joystick while swinging speed was fast or normal also if u set 1 foot on travel pedal and press lightly while swinging speed is normal. Any one know anything about kobelcos with the kpps test switch

i have the SK150 with this switch and since the throttle was disconnected long ago (now manual) I was figuring this switch did not do anything. I have not noticed any difference in the machine when i move the switch around but admit i have not played with it much. Is that true or is this hooked up to a hydraulic control?

 

[dirtdigger123]

On mine with the switch flipped it makes a lot of difference it handles more like an older machine the track motors are very strong and all digging is strong I think the switch turns the computer off. If pulling on a big stump or rock u can choke the motor down if not careful.

 

[MR. KOBELCO]

you must be careful, running your machine with the kpss switch off does turn off the computer control for the hydraulic pump pf solenoid.
but it is to be used only temporarily to move the machine over where your problem can be fixed.
running with the switch in release will put more strain on your hydraulic piston pumps and you will chew up the piston shoes.
provide me with your full model and serial number along with pictures of the machine and inside the cab switches, display, computer, etc...
i can see if i cannot isolate the root cause of your problem.
[email protected]

 

[MR. KOBELCO]

generally on a kobelco,
bucket is pump 1,
arm in is pump 2 and second pump (p1) kicks in to help for digging
arm out is two pumps
swing is pump 2,
boom up is 2 pumps
boom down is pump 1
R.H. track is pump 1
L.H. track is pump 2

by using the swing (p2) and activating the travels this causes the straight travel to actuate thus switching the pumps,
swing is then controlled by pump 1 and both tracks by pump 2
your machine may have a rocker switch which in fact does almost the same thing.
independent travel.
pump 1 runs the upper and pump 2 the lower tracks
this is one quick way in troubleshooting if there is a possible hydraulic pump problem
amoung a few more tests that can be done

 

[MR. KOBELCO]

check if there is a solenoid on your pumps.
there maybe one (standard) or possibly two ( 2nd is an option for variable loading )
if you have variable loading there will be a dial in your cab with a symbol of your arm and arrows. this dial varies the pumps via the controller (c-1) computer.
if you have a solenoid, turn your kpss back to on, usually the chromed toggle switch is down for "on".
turn key to "on" position, do not start the engine, go back to pump comp, undo wires conn, with a digital volt meter on dc volts, read by conn to both wires what the voltage is -> should be 24 vdc.
then with wires still disconn, turn your meter to check ohms and read the coil of the solenoid -> should be 15-30 ohms.
the pf solenoid & opt variable loading is powered via the computer for horsepower control thru the two 1 amp fuses.
when you turn off the kpss "release", the power comes thru another fuse and thru a current limiting resistor sending a constant miliamps to the solenoid partially destroking the pumps but not near enough under load. thats why she lugs the engine down.
let me know your results.
also let me know if she tracks straight or tracks to one side?
if this checks good i'll need you to guage into various pressure test ports on your pumps and by running some circuits stalled over relief i should be able to narrow down from there, better at that point to do over the phone.

 

[dirtdigger123]

Sounds like u know what to do . I will try and see what readings I get. I have a shop manual if it will help. Thanks

 

[stuntheavy]

Did this ever get resolved? I have nearly identical problems and curious what the issue was.