Pac Brake quit working

[Donald and Iris Lucke]

[size=14]When I turn the pac brake switch on the light comes on as normal and while driving the second dash light on the dash comes on but the transmission stays in 6th gear. I have lubed the actuating arm and exercised it, changed the relay K9, and sprayed every contact in the electrical bay that seems tied to the pac brake. The brake still doesn't work and the indications are unchanged. I need to know where the solenoid is located on my coach and how to test it.

Don Lucke, 2003 Monterey, Cummins ISC, rear radiator

[Roy C Tyler]

Well, since no one else has chimed in here, I will throw out a few things to check.  Is this a "new to you" Monterey or have you had it awhile and the pac brake just stopped working?  When you push the rocker switch on, the switch lights up but that is a separate wire so my first suggestion would be to pull the switch and check the wire contacts to make sure it is working ok.  I have added a BrakeSwitch (http://www.brakeswitch.com/) to mine so it does work a little different but the dash light only comes on when my pac brake is engaged. My switch light is on all the time since I leave my switch in the on position all the time. One other thing to check is the brake lights.  They are supposed to come on when the pac brake is engaged.  You might have someone follow you and see if the brake lights work as they should. Maybe a previous owner reprogrammed the transmission so that it does not shift down to 4th gear.  In that case, you would have to shift down manually. Depending on my speed, mine will drop into 4th or 5th gear and work its way down to 2nd if I let it get that slow.

[Harvey Ziegler]

Donald
It soulds like your lights are working as they should. The first light indicates that the PAC exhaust brake system is turned on. The second light should should come on when the Pac Brake is actually turned on and the solenoid should be picked up and puting air into the actuator of the Pac brake. The solenoid on my coach is at the back of the engine (towards front of coach) and was originally tied to the engine lifting lug. The hose from the solenoid to the actuator is only about 2 feet long. If your transmission is not shifting out of 6th gear the Pac brake will have very little or no effect on slowing the coach. I can not remember for sure but either the Aladdin or the transmission shifter key pad indicate 2nd gear as the sellected gear when the exhaust brake is active & attempting to slow the coach. If you apply 12 volts to the output wire from the exhaust brake relay (wire 127 I think) you should be able to pick up the solenoid and operate the Pac brake if you have air in your air tanks.
By your note it looks to me that someone has reprogrammed your transmission to stay in 6th gear.

[Joel Ashley]

I'm not sure if I'd ever be starting in 6th gear down a grade requiring my Jacob's "pacbrake".

Joel

[Gary Wolfer]

Most exhaust brakes are simple. First of all you have an air compressor or they work off the engine compressor. Then there should be a solenoid with two big lugs and two small ones that energize the air to the air cylinder that opens and closes the butterfly inside the exhaust brake. If you have power to one large lug and jump from it to the small lug that is furthest away you should be able to activate the pump. That will send air to the air ram(cylinder) that closes the butterfly When you disconnect the jump. If that works at the engine you need to check the wire from the dash. I know you have air bag suspension and that will be a little different but the same objective. The only difference being you will not have a dedicated separate air compressor for the exhaust brake. Just follow the air line from the cylinder back to the other end. Your exhaust brake should work in 6th gear but will not drop until it gets below a certain RPM. Hope that helps. If I remember right there is a power wire that goes to the ECM that drops gears maybe it has come loose.

[Donald and Iris Lucke]

Thanks for some new ideas on the pac brake problem. We bought the Beaver new in 2003 so the pac brake worked well for over 10 years. I have very bad access
to the front of the motor so am trying to rule out everything else before I try to find the solenoid. I recarpeted the bedroom so cutting the carpet to get that access
cover off is a last resort.

Thanks again
Don Lucke

[Gary Wolfer]

The solenoid is in the engine compartment. It looks like an old Ford starter solenoid. Usually mounted on the wall under the bed near where the air hose connects to the air source. Good Luck

[harry kew]

I have 1999 patriot  with 330 cat, when I put on the pac brake the one light comes on showing the switch is turned on  but there no second light comes on when the pac brake is activated.
Is there a second light for that year that should be coming on or maybe the light is burnt out?
When I first turn the key on before starting there is know second light showing on the dash.
And second my brake lights don't come on when using the exhaust brake.
We went down the road with the engine cover up and you can see the exhaust brake working and the trans. down shifts the way everything should work.
Is this normal for this year and engine for no second light and know brake lights when using the exhaust brake?
They all seem to work a little different between years and models not sure if this is normal for mine or not.
Great Forum, thank you.

[Gary Wolfer]

Harry I have a 98 Patriot and the switch that turns on the exhaust brake that is on the panel on the left of the drivers seat comes on and when the exhaust brake is on and you let your foot off the throttle and the rpm is high enough a light on the dash by the turn signals comes on it is a red light that says exhaust brake. Yours probably should be the same maybe the bulb is burnt out.

[harry kew]

Gary do your brake lights come on when you activate the exhaust brake?