2nd Gen Non-Engine/Transmission Jake Brake Hiss

[FLynes]

I've never had a truck with an exhaust brake before. Is the Mopar/Jacobs unit supposed to hiss, when it's sitting at idle? It sounds like a bad vacuum leak to me, but the unit works fine and the hissing goes away, when I engage the gears and get going. Thanks for the replies.

 

[george]

That's normal, wanna really hear that hiss? Remove your muffler LOL people in cars all around you stick their heads out of their windows looking to see if that sound is their tire going flat. :-laf

 

[FLynes]

George,



Thanks for the help. I don't think removing the muffler would go over too well with Household 6, aka "the wife" (if any of you are/were military, you'll get the joke), but it would be funny to see the reaction of those around me. :-laf

 

[RustyJC]

Well, considering the butterfly valve in the exhaust brake has pretty well closed the exhaust off, the exhaust gas leaking around the butterfly is certainly going to generate some racket. Yep, the hiss will draw some looks when idling at a traffic light, and it's perfectly normal.



Rusty

 

[AndyMan]

Yeah, I've got a straight pipe and a jacobs e-brake. Makes a HECK'UVA noise while sitting still!!! lol.

 

[JFlagg]

I had one my truck before upgrading my turbo, and it suprised me too. I was hoping for that big rig sound I'm in the army too, I definitely understand Household 6. Though I would say mine is more of a PAC clerk

 

[FLynes]

Not to get totally off the subject, but speaking of exhaust, has anyone here run the MBRP dual setup? I'd love to see pics of it, if you have. There's something about having dual exhaust I really like.

 

[Pavemen]

why are you leaving it on once stopped?

the one thing i like about my Banks Brake is that it shuts off once under 15mph.

 

[george]

Why not leave it on while stopped? It does nothing but raise the EGT's a bit. I leave mine on until I get ready to shut the truck off. When I get ready to shut down I turn the brake off and let the truck idle until the EGT's are below 300 degrees

 

[Pavemen]

I was just asking.

That hiss is annoying to me. My Banks has a warm up feature that engages it until coolant temp hits 125* and during that time, I can't wait for it to shut off.

 

[FLynes]

I agree with George. I just spoke with a guy at Jacobs and it doesn't hurt it one bit.

 

[RustyJC]

On the 2nd gen 24V trucks, Cummins actually recommends that the exhaust brake be left on if the truck is going to be idled for extended periods. This is to increase head and valve stem temperatures to prevent varnish formation in the valve guides and on the valve stems, thus preventing valve sticking and bent push tubes.



The only downside of idling with the exhaust brake on is that there's flow reversion into the intake that will soot up the IAT sensor, requiring periodic removal and cleaning.



Rusty

 

[DNewell]

Yeah, I've got a straight pipe and a jacobs e-brake. Makes a HECK'UVA noise while sitting still!!! lol.

Yup, I've got straight pipe and now the PacBrake, and it is quite a racket. It sounds really weird through the pipe. Sounds like a nice echo. I love it when it engages in 5th gear at about 70mph. Really sounds like a big rig!:-laf

Haven't had too many people look at me weird, but it sure sounds goofy when sitting at idle. Who cares about the people around me, the truck is loud enough with the straight pipe...