C12 jake brake

[Fred Nikirk]

Took my coach out for a run before heading south. The jake works on the high setting but if acts like its on the low setting any ideas? Have a 2001 pt c12.
Fred

[Mike Groves]

The effectiveness of the brake is based on engine RPM.  Can you describe what you were doing, how fast you were going, what gear you were in, what gear the coach automatically selects when the switch is pressed? 

Did you by chance, press the low option first, not feel a thing, then press the high option?  Is that what you're saying?  Depending on my speed the low selection can have little effect for me in some cases, then I press the high button.

Mike

[Edward Buker]

Fred,

If you get the RPM up in 3rd gear to say 1800 to 1900RPM and engage the Jake and rock the switch from high to low is there a difference in tone and braking? At low RPM it would be hard to tell. If that test indicates both positions engage low I think I would go to a Cat dealer given it is likely and internal engine Jake mechanical/electrical actuator issue.

Later Ed

[Fred Nikirk]

There is no difference between high and low. I had my trans reprogrammed so it doesn't automatically shift down try it at all different RPM same results.
Fred

[Lee Welbanks]

Take it to Cat.