Exhaust Brake ???
The other day coming over Donner Pass, going down hill, I let my speed build up to about 65mph, I switched on the exhaust brake and nothing happened, I let it go for awhile, and nothing, I finall...
Forum Discussion
What year is your cummins 8.3?
Modern cummins engines don't actually even have an exhaust brake. They have a variable vane turbo that controls boost (they don't have a wastegate either) and engine braking.
And all this talk about air compressors in pickup trucks adds nothing to this thread.
Our engine brake (2008 cummins 8.3) has little effect over 60 mph. As was said by others, letting the throttle (sic) off with the engine brake on will almost immediately show a 2 in the desired gear (left digit) on the allison display.
The system will downshift to 5th at 65ish, but little braking is felt. Under 60 it will go into 4rth, at this point the coach slows like it hit a wall.
And no, I don't leave it on all the time, especially on a highway. There will be many times you'd rather the coast just coach when you let off.
Modern cummins engines don't actually even have an exhaust brake. They have a variable vane turbo that controls boost (they don't have a wastegate either) and engine braking.
And all this talk about air compressors in pickup trucks adds nothing to this thread.
Our engine brake (2008 cummins 8.3) has little effect over 60 mph. As was said by others, letting the throttle (sic) off with the engine brake on will almost immediately show a 2 in the desired gear (left digit) on the allison display.
The system will downshift to 5th at 65ish, but little braking is felt. Under 60 it will go into 4rth, at this point the coach slows like it hit a wall.
And no, I don't leave it on all the time, especially on a highway. There will be many times you'd rather the coast just coach when you let off.
