Engine/Transmission (1998.5 - 2002) Pac Brake won't turn off

[rKortan]

Last night I turned on my exhaust brake coming down a grade and it would not release at the bottom of the hill.

I checked the vacuum, I pushed the button on the switch under the hood, I turned the cab switch on and off, no effect.

The only way I got it to release was turn the motor off and push the brake pedal several times to use up all the vacuum and then push the actuating cylinder by hand until it was fully released. What do I need to do next.

 

[Evan A. Beck]

The vacuum valve is most likely stuck. Remove the two small screws (not the Philips ones) that hold the solenoid assembly to the valve. Remove the spool valve from the body, and clean everything up real well with some Scotch-Brite and WD40. I see these things stick all the time, and most of the time it is just the vacuum valve. Since you can still move the butterfly, it rules that part out as a problem. Be sure to check all the wiring too.

 

[rKortan]

I took apart the spool valve and cleaned it. There was some carbon on the plunger that I sprayed off. Everything works great now. Once again the TDR membership has come to the rescue. I couldn't get along without everyones help. thanks... ... ... ... ... BK