Air parking brake sticks

erstanfo · 12-16-2013, 04:01 PM

My journey parking brake stick on if the coach sits more than 3 weeks. After air pressure is up and pop off has cycled, release the parking brake and coach won't move. Normally engine idle in Drive and the coach will start forward.
If stuck on, I have to depress the accelerator to move forward, the last time there was a Popping or clanging sound from the back then the coach lurched forward. Any suggestions?

JohnRR · 12-16-2013, 04:06 PM

Sounds like the brake shoes are sticking or trying to rust to the brake drum. Is this a first time occurrence?

Kuzzy · 12-16-2013, 04:19 PM

Could also be a leaking wheel seal. Or frozen brakes. ( I didn't look to see your location.)

Lightning83 · 12-16-2013, 04:24 PM

There is a Grease fitting on the tube that goes from your brake can to the s cam that's the rod that works the brakes Grease that and push the brakes a dozen times and see if that don't fix it

Heavyhaul · 12-16-2013, 04:24 PM

Quote:

Originally Posted by JohnRR

Sounds like the brake shoes are sticking or trying to rust to the brake drum. Is this a first time occurrence?

Agree that it could be. I have never owned a MH but spent many years over the road trucking and we used to pour rubbing alcohol in our air lines and pump the brakes a bunch to keep the moisture from freezing up the brakes actuators. Not sure though how you could do that in a MH unless your air lines have a disconnect.
We also would never set the trailer breaks when parking in very cold weather due to pads sticking to the drums.
Hope this gives you a little insight on air brakes and cold weather.

God bless

Lightning83 · 12-16-2013, 04:25 PM

Make sure your parking brake is off before pressing the brakes or the rod won't move

Pigman1 · 12-16-2013, 04:25 PM

Brake shoes are rusting to the drums when being held there by the parking brake springs. This could be caused by parking in a very damp area, an area where dampness is blown into one or more brakes, or other issues with excessive moisture in the brake area after parking like puddles forming under or near the rig in heavy rain. Some things you can do is keep the brakes from setting by starting it periodically and keeping air pressure up and using wheel chocks. To release them if they lock, idle the coach and shift repeatedly from drive to reverse and back 3-4 times. Another thing to check is to be sure when you brake cams were last lubed. THis needs to be done by removing the wheels and drums and adding high temp brake lube to the cams so they don't rust to the shoes or collect excessive corrosion. Not a hard job, but tires and drums need to be pulled. Heavy, dirty work, but easily done.

FIRE UP · 12-16-2013, 04:49 PM

Quote:

Originally Posted by Pigman1

Brake shoes are rusting to the drums when being held there by the parking brake springs. This could be caused by parking in a very damp area, an area where dampness is blown into one or more brakes, or other issues with excessive moisture in the brake area after parking like puddles forming under or near the rig in heavy rain. Some things you can do is keep the brakes from setting by starting it periodically and keeping air pressure up and using wheel chocks. To release them if they lock, idle the coach and shift repeatedly from drive to reverse and back 3-4 times. Another thing to check is to be sure when you brake cams were last lubed. THis needs to be done by removing the wheels and drums and adding high temp brake lube to the cams so they don't rust to the shoes or collect excessive corrosion. Not a hard job, but tires and drums need to be pulled. Heavy, dirty work, but easily done.

Great answer,
I've done the "S cam" clean and lube and, like stated, not all that hard but, you really should kind of know what you're doing in that operation. First off, if you've not removed those lug nuts, many of them are on there with some serious torque. Mine are 450 ft. lbs. I use a torque multiplier that I got off Ebay and it works so darn slick that I can sit on my duff and break those lug nuts with ONE ARM.

Then I use a tire/wheel dolly I got from Quartzite during the RV event (coming up this January) and that makes removing those 147 lb. Aluminum tire/wheel combos and, the 167 lb. Steel wheel/tire combo a snap to remove and tote out of the way.

Then I use a cheap, motorcycle jack to remove that 90 lb. brake drum and it just rolls out of the way without me lifting anything. Then, it's time to back off the slack adjusters so the "S cam" is basically sitting free with no tension on it. I then take it out and clean all the crud and stiff goo from it and the rollers. I then put a dab of high temp grease on all the contact points and put the whole mess back together. Oh yeah, I then re-adjust my slack adjusters to the point the brakes are just barely touching the drums. My brakes work flawless after that. No clunking, no sticking, nothing.

Yep, it takes about the better part of a day to do both sides, but, who cares. I saved a bunch of money that I can use for DIESEL FUEL, YAHOOO.

Scott

GENECOP · 12-16-2013, 05:06 PM

Good Info, I have experienced that a couple of times as well....thanks.

luckydog1949 · 12-17-2013, 11:26 AM

It's usually easier to break locked brakes loose by putting the transmission in reverse and let it roll an inch or two than it is going forward. We don't back up and hit the brakes nearly as often as we use them to stop or slow us when rolling forward. The brakes are "seated" to the drums better for stopping forward motion because of that; and, so resist forward motion more than reverse motion. I'm not sure that I'm explaining this well enough; but, brakes will pull themselves tighter when rolling forward than they will when rolling backward. FWIW...

erstanfo · 12-18-2013, 06:20 PM

Thanks I'll check it out after the Christmas holidays when I have time to get in the garage.

jerichorick · 12-20-2013, 05:56 AM

I had the 30K (I think it is called) chassis service done while I was at Gaffney, SC Freightliner. (This was done early but I was there so what the heck.) The cam service was in the routine.

Being in WA moisture is a problem. How is your stopping after you get going? Is there noise or chattering? Backing up, as suggested, to get the breaks broken free is a great idea. You could also try chalking the tires and release the brake when between trips. That will tell you if it is a rust problem.