Community Forums

Jackn · 06-24-2012, 06:03 PM

Hi All!

I recently replaced my PacBrake myself because the old one wasn't working any longer. After the install, I found that the new one won't work either. I tested the solenoid by jumping it and found that it will activate and cycle the PacBrake properly. I checked the fuse in the driver's side exterior panel and found it was still good. I only have a foot pedal switch to activate it. Are there any other key components that I should check? Also the wiring from the solenoid forward disappears into the engine compartment wall and I don't know where it goes from there. Does anyone know the path of that wiring forward so I can check it for shorts/disconnects? Thank you again, Jack.

Oh, 1994 Monaco Dynasty 38'

ROBTREE · 06-25-2012, 04:43 PM

Mine went bad also. It turned out to be the foot switch. Also check the brake switch to make sure it works

Yukon Jack · 06-25-2012, 05:59 PM

Jack,
I have a 2001 Monaco Dynasty 38 ft, with an ISC-350 that uses a PAC brake with only a foot pedal to activate the exhaust brake, which I assume would be very simlar to your coach.

About a year ago I had a problem with my PAC brake not activating when depressing the foot pedal. After checking the fuse which was OK, my next step was to test the Bosch style electrical relay that was located in the Front Electrical Run bay that is accesed through the same bay door, directly under the driver, that contains the PAC brake fuse that you checked. After I replaced the PAC brake relay, my exhaust brake system has functioned flawlessly ever since.

These are a very common, standard 12 vdc relay, (blade style, plug in relay) that are a small, black colored, square looking cube that can be purchased at NAPA stores or most any retail auto parts store. As a word of caution, make sure your N.O & N.C. pin-out configuration matches the one you purchase as there are a couple of variations. I would suggest replacing that relay before replacing any other expensive components. As you are likely aware, these systems are difficult to do much static tesing while parked in your driveway, as you almost have to test drive it to determine that the system is functioning properly.

As info, for the PAC brake to function, the exhasust brake system has to sense a 0-throttle position from the engine ECM before it will engage.

Hope this helps your efforts to correct your problem.

Happy RV'g

Jack

Jackn · 06-25-2012, 11:43 PM

Thanks guys. I will go locate and replace that relay when i get my rig out of storage next. I'll also scope out the foot pedal and see if I can diagnose it.

pwhittle · 06-26-2012, 05:17 AM

On my 94 Signature, the cruise has to be turned off for the PacBrake to work.

Paul

Jackn · 08-24-2012, 01:46 PM

Yukon Jack - You are the winner!! I replaced the relay and the PacBrake came to life. Sorry for the delay in thanking you, but my rig rarely gets out so I can test these new ideas. As my posts show, this has been a project that has taken waaaay too long, so I really appreciate your help.

Jack

jimschaechte · 08-26-2012, 06:11 AM

I have a 1994 Monaco Dynasty 34 ft with 8.3 cummins 6 speed. It has a PAC brake. The previous owner unhooked it at the control panel on the front driver's side. He said he used to use it all the time, but was chasing a shifting problem and thought it was related to the pac brake. He found the issue with the shifting and fixed it. It was unrelated to the pacbrake.

He never hooked it back up.

I looked at the wires in there for it. I see an identified circuit fo rthe pac brake. Unfortunately, there are 3 wires from the switch. white green and red.

Anyone help me as to where to hook them up? Thanks. Jim