Exhaust Brake not releasing

[alalcoolj]

I have a 1995 Country Coach that we just reconnected the exhaust brake after having a broken air line for years. It is a Intrigue with a Gillig chassis and 300 8.3 cummins. Now that we get the exhaust brake to engage we apply the throttle and it does not shut off. It is gettting stuck on. Isn't it suppose to shut off when you apply the throttle again.

[Hitchhiker]

The butterfly valve shaft may be seizing in it's bushings. If so, try disassembling it and apply some high temperature anti-seize to the shaft before putting back together.

[alalcoolj]

It is releasing when i switch it off but I guess it must be the carbon build up causing it to stick. I was thinking that it might be the activator and not the exhaust brake that was stuck. The air line was broken for six years. It has never worked since we have owned this coach.

[Paul R. Haller]

My guess is the air valve is sticking. Does a single air line control both activation and release? (its configured this way with a single air line going to an electric air valve and two lines from the valve to the cylinder on the exhaust brake) if it does, your air valve is probably sticking in the on position. They are notorious for this. Rust and water are their mortal enemy. Take it apart and clean completely then, use light oil on the air valve shuttle after cleaning with solvent, and reassemble. Be careful. They are spring loaded and very sensitive to dirt. test after doing this to be sure the air or vacuum is switching from one line to another with the activation of the electric switch. Check also the switch on the linkage is working.
As another poster mentioned, take off the airlines at the exhaust brake and with the engine off, try cycling the exhaust brake by hand. It should open and close easily. If not you may have carbon build up in the shaft and bushing. Sadly, if it does not actuate and release without sticking, removal and disassembly of the exhaust brake is necessary. That is a job. good luck,
-Paul R. Haller-

[cannon man]

we had same problem. mud dobers had pluged bleed hole with mud. good luck

[BigSkyBob]

Most exhaust brakes are air applied and spring released. There no way you can move the actuator to the applied position by hand because you would have to overcome the spring, but it's too strong to be able to do that. My guess is the return spring is either frozen or broken since it will apply and not release.

[J Walker]

Be careful not to operate the engine much with the exhaust brake stuck in the on position. A friend had his exhaust brake freeze shut and had to replace one of his manifolds as a result. Memory serves that it was his intake manifold but it might have been the exhaust manifold. I don't see how you managed to operate for six years without the exhaust brake. It is one of the best features on a diesel chassis and it was a must have when I bought my DP. The service brakes are very good also. I never had to test them on a long downgrade so I don't know about their tendency to fade.

[Mineshaft]

PacBrake sells a silicone liquid just for lubing exhaust brakes. It comes in a squeeze bottle and you apply several drops to the end of the shaft and the air cylinder a couple of times a year. Using a wrench on the actuating arm you may be able to gently loosen up the brake after several applications over several days.