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Exhaust Brake Issues

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Phil Sales:
On turbo charged diesel engines, gearing down,only works when accompanied by an engine brake of some type. These engines do not make back pressure like the N/A  (naturally aspired) diesels used to do and gassers still do. Hense the development of the Jacobs and other engine brakes. But try to tell the old guys why your brakes are hot, they don't believe you. LOL   Phil

Ken Sair:
We have a 40 ft. Contessa (2007). Ours also would not hold the coach back at any speed. Turned out it wasn't plugged in and was not working at all. After having it fixed it works very well. However, it requires an assist periodically from the service brakes to prevent speed build up on grades over 6%.

Its pitiful engineering to save money. A similar coach (Monaco Windsor) in 2006 came with a 2 stage engine brake. Drove one, WOW, like throwing out an anchor. Monaco in their infinite wisdom felt the exhaust brake was 'adequate' and went with that instead of the engine brake to save money. I know, I argued long and hard to get the engine brake to no avail.

These coaches need an internal engine brake, not an exhaust brake. Monaco got it wrong in my opinion.

Richard And Babs Ames:
Ken I do not know about Cummins options but CAT only offers the Jake Brake (engne) braking on its larger engines or C13 through C15. The C 7 and C 9 only have the exhaust option available.

 Recent redesigns such as Pac Brake's http://www.pacbrake.com/index.php?page=prxb-exhaust-brakes-2 and others offer better breaking preformance than the previous models. You could consider an upgrade to a newer technology exhaust brake system.


We find the original Pac Brake on our '97 preforms well as does the on on my son's Jayco Seneca with the Chevrolet Diesel engine as a suppliment only brake and our chassis service brakes have over half the disc brake pads left at 103,000 miles.

MarcRodstein:
Using the exhaust brake on a steep descent requires an understanding of how it works, and the proper technique. The exhaust brake is most effective at RPM's over 2200, but if your speed and RPM's build up above 2500-2600 RPM, your transmission will automatically upshift, which reduces your rpms and greatly reduces the effectiveness of you exhaust brake. For downhill control, periodically apply your service brakes to keep the engine RPM's below 2500 so as to avoid an upshift. You want to use the service brakes enough to control the engine speed, but not so much as to overheat the brakes. On an extreme downhill slope of 7% or more, start down in 2nd gear and use your brakes intermittently in order to keep the transmission in 2nd gear.  This requres descending at reduced speed (put your flashers on), but is much safer. If you allow the transmission to shift into 3rd or 4th gear, your braking and speed control will be greatly diminished.

Phil Sales:
Ken, I'm not sure which engine you have, but the C-7 and C-9 will not support the full Jacobs compression brake. It's not an available option for those engines. I have the older Cat 3126 HEUI and I can't have one on my engine either. But would love to have one because they are exponentially more effective.  The exhaust brakes are better than nothing though.

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