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Dan, Technician
Category: Construction and Road Equipment
Satisfied Customers: 5185
Experience:  17+ yrs. shop and field experience with all major brands of heavy equipment and trucks - 1995 WyoTech graduate.
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I have a case 435 that will not move in forward reverse the

Customer Question

I have a case 435 that will not move in forward reverse the levers move but the controls are locked so i can not operate the bucket. When it first started i could move the machine but not operate the bucket and after playing with it it would randomly begin working. I have checked for power at what i think is the parking solenoid and valve up front. It has no power and energizes when you take off the park button. I have removed that valve and plugged it with a hydraulic cap just to see if it would move. (May have been dumb but im trying anything im desperate at this point) still does not move. I have tried a new instrument cluster and returned it when that did not help. I have tried swapping the solenoid on the parking valve for a new one, all fuses are good and all relays pass on my relay testing tool. Nothing has worked so far. Now i want to be sure im in the right area i have a case shop manual for it but it is not very descriptive and the wiring diagams are almost useless as they dont tell you any color and i cannot find any labels in the machine of any sort. Whats next? is the parking brake valve the one up front under the seat area?
Submitted: 1 year ago.
Category: Construction and Road Equipment
Expert:  Dan replied 1 year ago.

Hi my name is***** will be glad to try to help. If the safety switches ( Seat, lapbar/seatbelt, etc) and harness test good and the park brake switch tests good as well as the harness to the solenoids and controller, and the solenoids are good then the problem is likely in the controller itself. Have the dealer bench test it and reflash/reprogram the software and let me know the results or if we have to dig deeper.

Expert:  Dan replied 1 year ago.

Also check the hydraulic filter for signs of metal/debris indicating a mechanical problem or pump/ component failure.

Customer: replied 1 year ago.
By controller do you mean the cluster? Or the hand controls? I'm confused the controls are mechanically linked to the pumps not electronically as far as I can see and I tried a new cluster I purchased at the dealer
Expert:  Dan replied 1 year ago.

There is a controller/ECU that works as a brain( computer module), This module gets its signal from your safety switches to know when to allow the functions to operate or lock them out.

Customer: replied 1 year ago.
Ok didn't know it had an Ecu. Wouldn't removing the parking brake valve and just putting a putting a hydraulic cap on the hole eliminate the ability for the Ecu to prevent the controls from not functioning and the machine would be able to move freely? Or no?
Expert:  Dan replied 1 year ago.

just to be sure we are on the same page with the correct vintage machine could you get me the serial number?

Customer: replied 1 year ago.
Serial number: N6M400710
Expert:  Dan replied 1 year ago.

click on this link for a PDF downloadable version of the service manual with full schematics, testing and adjusting info, repair info, and specs. I hunted one down for you and is a great tool to have on hand during troubleshooting.

Expert:  Dan replied 1 year ago.

Check inside the hydraulic filter for fine metal/debris just to be sure you do not have a sign of a mechanical failure occuring

Expert:  Dan replied 1 year ago.

Another thing to check is the pump drive coupling between the engine and pump for failure. You can remove the small charge pump on the end, disable the fuel for starting and crank the engine over to confirm the main pumps are turning. If all that checks ok then we can check for safety interlock issues or control valve/electrical issues. LEt me know

Expert:  Dan replied 1 year ago.

Hi, did you get this resolved?

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