? 4 Pac-Brake owners

[stick]

I haven't used my brake for a while, so I can't remember if it is supposed to sound like it does now (getting old).

When I turn it on and let off the throttle to slow down, the valve shuts like it should, but then I get a loud hissing sound, like it is bypassing a lot of air.

Iv'e check all of the air fittings for leaks, and the selinoid seems to be working properly. I just can't remember if it always sounded this way!



Stick

 

[SRadke]

It should have a lod hiss sound in the tail pipe. The air is suppose to leak past hte butterfly at 60psi. If it is leaking at a clamp you have a problem but sounds normal to me. A leaking clamp will noticeably reduce the effectiveness of your brake.



-Scott

 

[y-knot]

Mine sounds alot like the big semi's, of-coarse not nearly as loud but very close. Have no ideal what it sounds like at the tail pipe, I am always driving. It has never given me a single problem since it was installed, I love it. The amount of braking force it produces is not only great for saving the brakes, but very addictive.

 

[stick]

Scott:

There are no clamps-all pipe fittings. It is not the hiss that you hear at the tail pipe, more like it is dumping excess air.

Stick

 

[SRadke]

The clamps I'm referring to are the ones the attach the brake to the turbo and the turbo to the down pipe. The one between the brake and turbo being the critical one because this is where you'll loose your backpressure. If your compressor is not cycling or running all the time you don't have a leak in the compressed air system.



-Scott

 

[mbaston]

My first brake with the AFE air filter did not have as much of a hissing sound. However, this break would often freeze up. The replacement they sent me hisses like a mad cat. Pac Brake told me that the newer brakes have looser tolerances between the butterfly and the elbow causing an increase in the hissing sound.