exhaust brake rattle??

[vhainesxx]

I just took the muffler out of my truck and am running the straight pipe out of the truck. I'm very happy with the results of the straight pipe, but when I hit the jake brake switch (its a pac brake and it was installed when I bought the truck and it works well) something is making a horrible metallic rattle. When I kill the Brake switch it stops so I know its the brake doing something.

Does the Jake brake baffle need backpressure to operate properly or at least a bend in the pipe or is there some adjustment on the brake somebody help

!!

 

[Dieseldemon]

Check the vacuum to make sure it is holding the valve shut and no it does not need back pressure or a bend in the pipe