Community Forums

robisinwa · 01-07-2015, 12:40 PM

Hi all... 2003 Monaco Dynasty, Cummins 400 ISL with 2 stage Jake break... Was working, driving down the road, near pass peak and figure out no longer work... Press the pedal and nothing. Repair guy has come by and plugged into engine computer...no error codes. Checked fuses and relay, check ok. Repair guy can't come with anything other than it's the foot pedal so now waiting on part courier to bring out a new one from a couple hours away.

Just don't want to take a 6% grade for 5 miles without it working. Anyone else have any ideas of what to look at or similar experiences to share?

Thanks in advance

jacwjames · 01-07-2015, 01:14 PM

Were you using cruise control when the jake brake quit working???

I believe there is a sensor on the brake pedal assembly that sends signal to deactivate cruise and lets the jake brake work. I've heard/read that the wires get loose or corroded. You might unplug the wires and reattach to see if that helps.

Gordon Dewald · 01-07-2015, 01:29 PM

Stick your toe under the accelerator pedal and lift up.

BFlinn181 · 01-07-2015, 01:47 PM

Are you talking about a true Jake Brake™ that changes the lift of the exhaust valves to create compression or an Exhaust brake that closes off the exhaust to create back pressure to slow the engine?

A Jake brake™ is much more complicated than an exhaust brake, although the Jacobs Company does sell exhaust brakes. They often offer to stop normal valve opening of 2 or more cylinders to retard the engine. These compression brakes hold pressure in the cylinder then releases it in an explosive, very noisy manner. That's why so many communities have ordinances against Jake Brakes.

An exhaust brake, mounted just after the turbo, is usually a butterfly valve that is turned by a lever to partially block the exhaust gasses. It is powered by an electric or air powered pushrod. These mechanisms often get rusted or sooted up and stop working.

Another type of exhaust brake actually changes the air flow in the turbocharger to create back pressure.

What type of 'Jake brake' are we talking about?

robisinwa · 01-07-2015, 03:46 PM

Cruise control definitely not involved, though have used both at same time without problem... I am have programmed myself to tap brake pedal first to disengage cruise and then left look presses the Jake pedal to truly slow down with.

For clarity, my data card says exhaust brake by manufacturer Jake though it does not have a model or serial number.

robisinwa · 01-07-2015, 03:53 PM

One more comment ...press the pedal and nothing happens... In my mind if it was something in the Jake itself, at least the transmission would still show a '2' and it would kick down to a lower gear, which is not happening.

robisinwa · 01-07-2015, 09:17 PM

It was the foot pedal... Spliced in the new one and all good again. Thank goodness I waited cause the down hill was very long and steep with no flat parts.... (North of LA on I5 down into Bakersville)

I used FedEx courier to get the part delivered same day from Irvine, not cheap but was speedy.

Koop · 01-08-2015, 11:02 AM

Thanks for posting the outcome. It always helps when we know what fixed the problem.

pub1898 · 03-04-2015, 05:50 PM

2003 Travel Supreme ISL 400. I believe I need a new rocker 2 position console switch but I'm having trouble finding one. For a time the Jake worked on High only, then it quit working altogether, now it only works on Low after I pulled the switch to check for power.

slickest1 · 03-04-2015, 07:07 PM

Quote:

Originally Posted by pub1898

2003 Travel Supreme ISL 400. I believe I need a new rocker 2 position console switch but I'm having trouble finding one. For a time the Jake worked on High only, then it quit working altogether, now it only works on Low after I pulled the switch to check for power.

Have you tried a heavy truck parts supplier. They are a very common part that should be readily available.