PacBrake Stuck?

[Cdogg]

Coming to work this am, stopped at corner, took off and it seemed as though the Ebrake was stuck? Sounds like a regular big rig (deep sound), can feel no exhaust from the tailpipe, smells like exhaust around the truck? What gives?

 

[RTuvell]

After you have warmed up the truck set the parking brake, put the vehicle in neutral, turn on the exhaust brake, pop the hood, and have someone step on the accelerator and then let it off while you observe the exhaust brake. If the exhaust brake is working properly you should be able to see the actuator move, if not you have a problem. IMHO it would be rare for an exhaust brake to fail in the fully actuated position.

 

[Cdogg]

Actuator is moving?

 

[RTuvell]

The exhaust brake is actually a butterfly valve in the exhaust stream. In the open position it does not restrict exhaust flow. In the actuated position the butterfly valve turns until it restricts exhaust flow. The exhaust brake (butterfly valve) moves to the actuated position during engine deceleration when the exhaust brake has been turned on. The actuator sits on the outside of the exhaust pipe and is attached to the butterfly valve by a rod.



You appear to be concerned that your exhaust brake is stuck in the fully actuated position. You can check this by observing the operation of the exhaust brake. You can observe the operation of the actuator by watching the "rod" during engine deceleration to see if there is any motion of the rod which there should be. You can also observe to see what is happening when there should be no motion of the rod. After you have warmed up the motor you can observe the "rod" at startup with idle only (no acceleration) with the exhaust brake both on and then off. During this test there should be no movement in the "rod" if the exhaust brake is operating properly.

 

[SRadke]

It should make a hissing sound at the tailpipe if it's closed (activated).



-Scott

 

[sangell]

MY Pac Brake failed in the activated postion while on a trip last labor day. I had to pull the inline fuzz to get the brake to release. Turning the switch off did nothing.

I called Pac Brake and was informed they were having trouble with the silonoide and they sent me a new one along with a new mount to relocate the compressor. The customer service was great, the brake taking a dump in the mountains of CO while weighing almost 24K sucked.



Scott

 

[Cdogg]

OK... Here's the deal!!!! After a little more investigating (checking Pac wiring, hoses, solenoid) I worked my way back from the Pac and low and behold right behind the Cat. Conv. the exhaust pipe had broken clean off at the weld. I then proceeded to the ******* for a quickie weld job. After 2 hrs in the waiting room I was told my baby was ready! The service writer then informed me that I would need a new Cat. Conv. and it should be in Wed. OK!! I then asked if the hanging pipe had been repaired until the new Cat came in, Nope still hanging and a big we don't weld here!!! After much debate with myself I thought OK I can wait until Wed but I'd better check on that part with the writer, THE PART IS ON B/O FOR AT LEAST A MONTH!!!!!!!!!!

 

[SRadke]

Are they doing all this work under warrantee? If not save your money and buy a 4" turbo back system, you'll be better off in the long run. I can't imagine what would have to have taken place to break the pipe in the first place unless it was just a terrible weld job.



-Scott

 

[Cdogg]

It is a warranty repair, part is on national B/O at a cost of $890. Weld had to be bad. I cross RR track daily on the way to work and that is what shook it loose.