Parking break switch leaks all my air when pushed in

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Parking break switch leaks all my air when pushed in

August 14, 2019, 02:05:07 pm

Sitting in the middle of the Adirondacks with an air brake problem. I can air up to level and the travel light comes on.but when I push the switch in to release the brakes air starts leaking out. It sounds like it may be coming from the switch itself but not positive. As I said the level works and the coach airs up until the switch is pressed in. Any ideas on how to trouble shoot this? Is it possible to bypass. Hope someone can advise cause I'm 30 miles from the nearest small town(saranac lake).lucky we're here for the next 9 days.

Re: Parking break switch leaks all my air when pushed in

Reply #1 – August 14, 2019, 02:11:06 pm

The seals go bad in the air release. They are available at most truck stops. If your air is staying above 90 psi with the leak go ahead and travel to where you can buy one. This advice is only if it is leaking at the release valve because it can't be bypassed. If you find the leak somewhere else get back to us with the new info.

Re: Parking break switch leaks all my air when pushed in

Reply #2 – August 14, 2019, 03:08:15 pm

That could be it. It won't stay above 90 so I guess I need to get a seal. Is there a specific seal size and is there a diagram that shows where it goes. Sounds like something I can do.

Re: Parking break switch leaks all my air when pushed in

Reply #3 – August 14, 2019, 03:15:56 pm

You need a valve, you can replace it with minimal hand tools.

Re: Parking break switch leaks all my air when pushed in

Reply #4 – August 14, 2019, 03:17:15 pm

I'm sure google or YouTube would be your friend right now. Good luck

Re: Parking break switch leaks all my air when pushed in

Reply #5 – August 14, 2019, 03:26:16 pm

Raise the dash lid and look down or get on the floor and look up, whichever one gives you the best view and access to it.

Re: Parking break switch leaks all my air when pushed in

Reply #6 – August 14, 2019, 03:26:27 pm

here is one

Amazon.com: Truck Trailer Air Brake PP7 Dash Control Valve: Automotive

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Parking break switch leaks all my air when pushed in

Reply #7 – August 14, 2019, 03:54:18 pm

Had the same problem, but, it was the SWITCH on the bottom of the Air Valve leaking.
Replace both due to their age, but just a thought.
Good luck and safe travels.

Re: Parking break switch leaks all my air when pushed in

Reply #8 – August 14, 2019, 04:53:00 pm

Is the switch integrated into the valve?It looks like the part Dub linked will replace the entire valve switch. It does look like what I've got. Do I need to order more than the valve replacement? Also how do I detach and reattach the small airlines?
I'll see if I can YouTube as well. If this works I owe you all a couple beers.

Re: Parking break switch leaks all my air when pushed in

Reply #9 – August 14, 2019, 04:54:24 pm

My parking brake control rebuild thread should help you out:

Bendix PP-1 Repair Kit

Re: Parking break switch leaks all my air when pushed in

Reply #10 – August 14, 2019, 06:14:53 pm

Thanks for the link. The link to amazon was also helpful.maybe I can order through the local Napa store? Tupper lake has one 20 minutes from here. Amazing timing as we were backing into our camping spot after a 450mi trip when the valve failed. No warning .

Re: Parking break switch leaks all my air when pushed in

Reply #11 – August 14, 2019, 06:28:14 pm

We replaced our Brake Release with this:

Parking Brake (Yellow Knob on dash)
Haldex 20021 dash parking brake release valve.

Valve Dash PP1 Hand Operated Push-Pull Parking, KN20021, Haldex

Good Luck, Dave A

Re: Parking break switch leaks all my air when pushed in

Reply #12 – August 14, 2019, 06:33:16 pm

Quote from: goldbehen – August 14, 2019, 06:14:53 pm

maybe I can order through the local Napa store?

Yes you can.
I drink Bud Heavy.

Re: Parking break switch leaks all my air when pushed in

Reply #13 – August 14, 2019, 07:10:38 pm

You might want to explore Saugerties, NY. If you're lucky you might find a fantastic family owned Italiian restaurant.

Re: Parking break switch leaks all my air when pushed in

Reply #14 – August 14, 2019, 07:50:12 pm

I'll keep saugerties in mind on the way home. We're about 90 miles south of Montreal. Maybe 30 mi from Lake Placid. Plattsburgh is up the road and might have some truck part supplies. I'll check the local Napa in the morning. They close at 5pm.

Re: Parking break switch leaks all my air when pushed in

Reply #15 – August 14, 2019, 08:37:58 pm

I used to motorcycle tent camp in Schroon Lake, NY and for decades the spring opener was the Rhinebeck Antique Car show at the Duchess County fairgrounds. That's local to Hyde Park, NY and the Vanderbilt and Roosevelt homes along with the FDR Presidential Library. Not to forget that Rhinebeck, NY is home to Cole Palen's Rhinebeck Airdrome, where I understand, they're getting back to flying the original WWI airplanes. You're in a great part of the country.

Re: Parking break switch leaks all my air when pushed in

Reply #16 – August 14, 2019, 09:19:13 pm

Quote from: Old Toolmaker – August 14, 2019, 07:10:38 pm

You might want to explore Saugerties, NY. If you're lucky you might find a fantastic family owned Italiian restaurant.

I'll bet you we've eaten there

Re: Parking break switch leaks all my air when pushed in

Reply #17 – August 14, 2019, 09:45:21 pm

Take the valve out and jump in the toad . FleetPride has locations in Plattsburg and Burlington Vt. Call ahead .
Do a google search for FleetPride address. Get an exact replacement . Should be easy peasy.
Of course there will be many other good parts locations also . Not a hard part to source

Re: Parking break switch leaks all my air when pushed in

Reply #18 – August 15, 2019, 01:48:57 pm

Quote from: Michelle – August 14, 2019, 09:19:13 pm

I'll bet you we've eaten there

Would that be the somewhat quirky family owned restaurant?

Re: Parking break switch leaks all my air when pushed in

Reply #19 – August 15, 2019, 06:07:29 pm

Any suggestions for getting the yellow knob off the shaft. Looks like some type of compression pin. I don't see any obvious way to get it loose. Appreciate all the help so far.I ordered the haldex valve from Napa. Should be in tomorrow.

Re: Parking break switch leaks all my air when pushed in

Reply #20 – August 15, 2019, 06:46:19 pm

It's a roll pin, drive it out with a punch or grind a nail point flat, and use it.

Re: Parking break switch leaks all my air when pushed in

Reply #21 – August 15, 2019, 08:16:55 pm

Quote from: goldbehen – August 15, 2019, 06:07:29 pm

Any suggestions for getting the yellow knob off the shaft. Looks like some type of compression pin. I don't see any obvious way to get it loose. Appreciate all the help so far.I ordered the haldex valve from Napa. Should be in tomorrow.

Buy a set of punches. And you need something solid to support the other side of the shaft. I, personally, am way too old for makeshift tools.

https://www.napaonline.com/en/p/AIT70557

Re: Parking break switch leaks all my air when pushed in

Reply #22 – August 16, 2019, 03:29:26 pm

Use a small socket on extension , clamped in vise for a backup. Cut the pointy end off of an appropriate nail . Tappy tap .

Re: Parking break switch leaks all my air when pushed in

Reply #23 – May 11, 2020, 04:17:05 pm

I've read a number of threads about these air brake parking valves. This seems to be the most recent.
On my way back to MI from FL, last month, my park brake valve suddenly began HISSSSIIING loudly when I released it after fueling.
I was able to drive without having problems with level system or brakes. The hissing stopped whenever park brake was applied.

Back home, I ordered valve number H-3158 x-ref KN20021. It seems to be like the one that blew a seal, which might have already been replaced since 1999. When my local mechanic replaced the valve last week, he said the attached electric pressure switch (for instrument panel indicator) was also leaking, albeit much less than the actual valve was. It is on order.

I ordered the valve rebuild kit Haldex 281126K so as to rebuild the replaced valve. I managed to get the back cap off, although I didn't have any sort of spanner to fit the three notches in the threaded back cap. Now I can't figure out how to dismantle the pieces and parts from the spring-loaded shaft. There is no exposed threaded area. In fact, I can't see the nut at all. can't see what is holding the rubber disc sort of thing (with metal hub) in place. It is the part on the end of the shaft farthest from the yellow knob.

Re: Parking break switch leaks all my air when pushed in

Reply #24 – May 11, 2020, 04:43:17 pm

Post a picture. I have replaced parking brake seals on several different parking brakes, need to see which one you have.

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