Author Topic: Exhaust engine brake / compression engine brake Operation  (Read 693 times)

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Offline David.e.atherton

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Exhaust engine brake / compression engine brake Operation
« on: February 05, 2020, 07:49:11 PM »
Operating motorhome with exhaust brake and motorhome with compression brake on all the time. Problems
have surfaced engine heating and low oil pressure. Motorhomes with exhaust brake, the flapper that restricts the exhaust discharge over time sticks partly in closed position retaining heat within the engine. Engines
That compression brakes been left on all the time, have ran into same heating problem. Where the trends
are similar with two different types of operation exhaust brake and compression brake. Using diagnostic tool
Cat ET, the troubleshooting readout indicates same heating and lower oil pressure. Engaging exhaust brake
At speeds faster than 45 mph , the engine exhaust pressure will not allow the brakes flapper to close. Engines
with compression brakes engaging at speeds faster than 1800 is not recommended as possible valve train
damage. Ask Dave, Dave Atherton Retired Cat Mechanic

Offline Brett Wolfe

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Re: Exhaust engine brake / compression engine brake Operation
« Reply #1 on: February 06, 2020, 08:01:24 AM »
Actually there are two primary causes of the exhaust brake "flap" hanging up/seizing:

1.  Lack of use-- the longer it sits unused the more likelihood it will seize in place.

2.  Lack of proper lubrication.  From the PacBrake website:

And yes, the exhaust brake can seize in the "always open", partially closed or closed so much exhaust is so severely restricted that power is way down and engine temperatures way up positions.