2nd Gen Non-Engine/Transmission Jacobs brake question in 2001 RAM

[DLangford]

I had a Dodge dealer install a Mopar/Cummins Jacobs exhaust brake in my 2001 3/4 ton Ram- 6 speed H. O. After installation it seemed to function normally. After a few weeks I flipped the switch, and while it did activate, I heard a strange sound. THe sound was like the hiss of a vacuum leak that sounded like it was coming from behind the passenger side outside the cab. Also, I thought the retarding power might be a little less of the exhaust brake.

I popped the hood and tried to find any vacuum leak around the unit but did not find anything with he first look.

Any suggestions before I take it back? It is 25 miles to the dealer.

 

[DavidC]

Are you talking about a hissing sound with the brake engaged and decelerating?. If the answer is yes it is a normal sound, mine sounds the same way as long as the sound is bouncing off a concrete divider or other object. I agree it sounds like a massive vacuum leak.



Dave

 

[GFrance]

It's not like the jacobs engine brake on a big rig. It doesn't have that roaring sound of compression. The exhaust brake sounds like someone is letting air out of your right rear tire at an alarming rate. :-laf

 

[aviatorman]

I Have a 2002 H. O. 6 spd and a Jacobs brake. The hissing sound is normal when the brake in on and the engine at idle. As soon as you go off idle, the brake opens and the hiss stops. The best answer for the hissing is the back pressure of the exhaust in the butterfly chamber. Long story short, ,I don't think you've got a problem.

 

[DLangford]

Thanks for the responses.

You may well be correct. When I heard it it may have been in a situation where the sound seemed louder than before due to the road or surrounding materials. It still decelerates the truck when activated.

I guess I just am leery of the vacuum leak sound and need to get used to it.