How does the Jacobs Extarder work?
My m/h is a 1994 Allegro Bus, 5.9B 230 hp (mechanical engine) Cummins DP. It is equipped with a Jacobs Extarder. From what I understand, to stop confusion in what it's called, it is now just called ...
Forum Discussion
OP, it sounds like you did not manually downshift to a lower gear when you tried Wolfe's test. You need RPMs (2000+) to get good braking from our engine/exhaust brake. At 60 mph you need to turn it on and manually down shift to 5th. Once the rpms get below 1800 you need to go to 4th and the same for 3rd. Does this get you slowed to say 20 faster than just taking your foot off the gas at 60? Until you time the difference you have not proved anything.
