Jake brakes very rough

[Rawze]

The main cause of the jake brakes being rough is fuel getting into the cylinders during jake operations.

On the CM870 and 871's is is usually worn down fueling(metering) actuators, or sometimes a leaking injector, where the timing circuit inside an injector is letting fuel into a cylinder. - Seen both of them plenty.

On the newer engines,... it is very common too, because of leaky electronic injectors.

so...


Start by doing an injector leak test and see if it passes a leak-down test.
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