menzy

Just got my brake put in yesterday, not to bad to put in. I have a horrible hissing noise when the truck is at idle and the brake in on. When I am up to speed I dont hear the hissing tho, Im thinking leak on the turbo to brake flange, but cant really tell, I will take apart when I get home on the weekend and check. My Cat is missing and I have an aeroturbine muffler with the stock resignator still in.

Anybody else have this happen??

thanks

cbrahs

they all make a hissing sound at idle with the brake applied.

menzy

its a horrible sound, like a large air leak from a large air compressor???? Does that sound familiar??? Is that right?

JCLeary

When the engine is cold and at idle, it will make a hissing sound. Having a non-resonated muffler like an Aeroturbine will make this sound pronounced. Once the truck reaches 170 degrees, it should stop engaging at idle and the truck should sound normal.

The hissing comes from the exhaust having to flow through the small orifice in the butterfly on the PRXB. Completely normal.

If there's a hiss coming out at operating temp, then I would search for an exhaust leak. Seeing that you have a Smarty, it shouldn't be hard to find soot if there's a leak...

menzy

Ha Ha I found it, there is a leak between the exhaust manifold and the turbo housing, only when the brake is on. Thats my crazy hissing noise.......