763 randomly does not move

[titan_cnh]

Working on an older 763. Encountered this issue when getting off to open a garage door and got back on. Machine would lock out of moving forward after getting back in from opening the door. Reversing slightly and trying to drive forward again seemed to unlock it and had no issues with drive again until the next time I went to open to the door and the unit did it again. Don't have much experience with the drive system on these units. Any help would be appreciated.

 

[flyerdan]

Every time you raise the lap bar, a parking solenoid drops a pin in a rotating disc to act as a brake. If you put the bar down and hear a click, that's the signal going to the solenoid to release the brake. Since it released when you back up a bit and take the pressure off of it, I'd suspect that it's getting weak. The lap bar and controller are working as intended, so that would be the likely culprit.

Edit to add: Does the machine creep forward a bit? If it does, that could be putting just enough force to keep the brake solenoid from releasing.

 

[titan_cnh]

Every time you raise the lap bar, a parking solenoid drops a pin in a rotating disc to act as a brake. If you put the bar down and hear a click, that's the signal going to the solenoid to release the brake. Since it released when you back up a bit and take the pressure off of it, I'd suspect that it's getting weak. The lap bar and controller are working as intended, so that would be the likely culprit.

Edit to add: Does the machine creep forward a bit? If it does, that could be putting just enough force to keep the brake solenoid from releasing.

What would be would be a good way to test that solenoid? I believe you are referring to the solenoid under the cab at the front center of the chaincase. Would putting 12 volts to the hot wire with something like a power probe work or is that not the correct voltage for it.

 

[flyerdan]

What would be would be a good way to test that solenoid? I believe you are referring to the solenoid under the cab at the front center of the chaincase. Would putting 12 volts to the hot wire with something like a power probe work or is that not the correct voltage for it.

There is a whole section in the service manual about the traction lock system, I'd advise that you get the manual (it's in the manual thread) as they have all the info there.