PAC BRAKE vs. JAKE BRAKE

[LEAH DRAPER]

I have a 2008 Contessa w/Cat C-9 (425 hp) with the Pac Brake.  I had hoped to change it out for the PacBrake PXBR upgraded brake but learned that with the diesel particulate system I could not change it out.  

Does anyone know whether the Pac Brake can be replaced with a Jake Brake which seems to be much more effective at slowing the coach on steep grades (prior experience with C12 Cat engine)?

Gerald, your thoughts?

Leah

[Richard And Babs Ames]

http://www.jakebrake.com/products/rv.php  


Do not think a "Jake Brake" is available for the C-9 Cat engine. You will find them only on the C-13 and larger.

[Gerald Farris]

The engine compression brake (Jake Brake) that you are referring to has never been designed for the C-9 engine that I know of by either Caterpillar or Jacobs Vehicle Systems (Jake Brake).

A compression brake is more effective at slowing a coach than an exhaust brake, but because it is more complicated and expensive to produce it is only made for engines of at least 10 liters or above. Most applications are for trucks that do not have the weight and downhill braking problems that justify the expense unless they are running the larger engines to get the weight up the hill to start with, as truckers are usually in a hurry.

If you are having downhill speed control problems with your coach when the OEM exhaust brake is used, my suggestion would be to slow down to about 25 or 30 mph at the top of all hills to let the coach downshift to 2nd or 3rd (when the exhaust brake is turned on) to keep the engine RPMs up enough to get maximun engine braking.

Gerald    

[Richard And Babs Ames]

Mazimum RPM when brakeing with your engine is 2300-2400 RPM before it will upshift to prevent over reving the engine and your CAT engine is still under warranty. Get an authorized dealer to check for proper operation if you have not already done so.

[LEAH DRAPER]

THANKS GUYS for your input, appreciate it greatly.  Boy the "learning curve" from the Jake brake (99 THUNDER) TO THE OEM brake on the Contessa is sure something to get used to.

[Tom Rogers]

I'm confused .... I have a 2006 Monterey with C9. When I had the valves adjusted I looked down into the engine compartment. I asked the mechanic to point out various parts of the motor. He pointed to the braking system And on the housing it said Jacobs Brake ..... is this not a "Jake Brake"

[Gerald Farris]

Jake brake is a term commonly used for an engine compression brake because the design was pioneered by Jacobs Vehicle Systems. An engine compression brake is located on the overhead (valve train) and under the valve covers so it is not visible until the valve covers are removed. The engine compression brake operates by opening the exhaust  valve momentarily as the engine reaches the top of the compression stroke, therefore turning the engine into an air compressor.

Likewise the 'exhaust brake' is commonly called a pac brake because Pacbrake Corp. was one of the first developers of the exhaust brake, although both manufactures now market both designs.

The exhaust brakes that are used on the new engines with a diesel particulate filter is a variable geometry turbocharger that uses the turbocharger to restrict the exhaust instead of the valve that was used on the previous engines.

Gerald

[LEAH DRAPER]

Am glad to see that I am NOT the only one with confusion about these braking systems, HOWEVER, I have to say that I am NOT impressed with the new DPF  systems interaction with the the turbo charger for it's braking ability.  Quite honestly it scares the HELL out me going down grades!  I think it is a real safety issue.  I will grant that my experience with this new brake is not great at this point and hopefully I'll become more skilled.  

Leah