hi guys -

i have a question about the brakes on a motorhome.

i see that most of the units have what is listed as an "exhaust brake" and i know that tractor trailer units have a "jake brake"

i have heard the loud popping type noise when a tractor trailer is going down a hill and assume that is the jake brake, but i have never heard a motor home doing the same thing.

that is why i thought they were different things.

thanks for your help,

gil

Gil:

Exhaust brakes are controlled by restricting the exhaust flow.

Jake brakes (also called engine brakes or compression release brakes) control the pressure built in the cylinders essentially turning the engine into a compressor.

I assume that the loud "pop pop" sound that some trucks make is from older designs of Jake Brakes. My rig has a combination exhaust/compression brake and while it makes some noise when activated it is very tolerable. I still turn in off in the 'no jake brake' zones.

I sent you a PDF file from Detroit Diesel that has extensive descriptions and diagrams.