I recently returned from a trip in the mountains. Before leaving, I serviced the pivot points on my Pac-Brake, as best as I could. I could not get the Pac-Brake to open & close by hand, so I lubed the areas that I could get to with an approved synthetic lubricant.

The first few times I used my brakes while descending the mountain, the coach made a loud whistling noise. I couldn't tell for sure, but it sounded like the Pac-Brake was possibly hanging up. The noise went away after 3-4 applications of the brakes. This has never happened before.

Anyone experience anything similar?

Craig

Interesting. I always worry about this happening. We just got back from about 1-1/2 weeks of vacation and before we left, I liberally lubed the pivot points, shaft etc.

I found that I really had to work the Pac Brake while I was lubing it as the shaft and butterfly seemed to be sticking a bit and I am sure the rust on some parts of the linkage do not help. The more I worked it, the further I could get the shaft out of the cylinder. We had no issues with it but it still makes me wonder.

I know the Pac Brake lube is designed to last a long time but I now lubricate it before every trip. Since we go out for 3-day weekends quite often, it is cheap insurance IMHO.

I have been thinking about taking it off and sandblasting the rusting components, then having them Jet Hot coated. I think it happens due to the high temperatures and the cheap zinc or cad plating on these parts. The Jet Hot coating would cure this for ever so the next time I look at it, I'll take some pics and post for comments.

I was uanble to move the mechanism more than an inch or so, which prevented me from lubing most of the shaft. It felt like it was being restrained by a heavy spring or something.

I believe it is. This is the spring for the butterfly valve that is inside the tubing/hose.

The more I worked it, the easier it was to lube up the shaft but it still only moves out about 1" or so. You really need two people to lube the shaft and pivot...or a tool to open it up as leverage is what is needed and I didn't want to bend/break anything.

I'll post my pics this weekend (or Monday at the latest) so let me know how similar/different it is from yours.

Ken

About the only way to open that valve is with a pair of channel locks. Thanks for the reminder..

I've been having trouble with my Pac-brake as well. If I use channel locks and break it loose and lube it before I leave it will work, but not on the return trip home. You can hear it try to engage, but the flipper won't actual move. I'm thinking that it's getting stuck due to a build-up of soot in the exhaust pipe at the flipper location. I was thinking of taking it apart and cleaning inside the tube. Hopefully, that will fix the issue.

I have read that the best maintenance for an exhaust brake is to use it. Mine has been on full time since 3/04, when I bought my 2004 DSDP. When I am going down hill and don't want it to engage I feather the throttle.
I was in the habit of depending on my exhaust break so much that I didn't use my service brakes enough and they were starting to glaze. Now I try to do some fairly aggressive stopping with the service brakes during each trip.
Tom

Someone in another forum suggested doing this when lubing the mechanism, to get access to the Pac-Brake shaft:

You must use a 12-volt dc jumper to activate the pac brake. Best to disconnect the electric plug, then connect a good ground to one pin and 12-volts to the other. That is the only way to operate the pac brake.

Anybody try this?

Craig

Activating the Pac Brake can be done by disconnecting the air line to the unit and using compressed air to operate the cylinder. I use a rubber tipped blow gun to accomplish this task. A second advantage to using air is that you can apply a little lube to the inside of the cylinder while operating the pivot points of the mechanism.

quote:

Originally posted by B.C.:
Activating the Pac Brake can be done by disconnecting the air line to the unit and using compressed air to operate the cylinder.

I'm confused then, are they 12V or Air operated?

Craig