Community Forums

OldForester · 01-24-2009, 06:18 PM

Our '06 has started to develop a problem with the Haldex parking brake switch on the dash. When I released the brake today for a short drive, the coach moved a few feet and gave me the "low air suspension" warning. When I tried to re-apply the parking brake it didn't have enough air pressure to let the brake spring apply.

By rotating the switch clockwise I found it went between releasing small bursts of air (or vacuum, not sure which) along the side of the switch just under the yellow knob. Finally, after a number of rotations, the switch seemed to tighten and the "low air suspension" warning went away, and the parking brake worked fine.

So I drove the coach to my destination, then to put on diesel,and then back to the storage area with no problems.

Upon inspection, I could find no problems with the switch. But I'm concerned there's a leak developing and want to replace the switch.

I have three questions -- 1) have others had this and what did they do, and 2)do all these coaches share the same switch, or might I have a different one the '06, and 3)if so, is there a part number for this switch that someone may have available?

Doesn't look all that difficult to change, just want to make sure I get the right one if I do need a new one.

Oregon Coyote · 01-24-2009, 07:23 PM

Spring brakes do not utilize air to apply the brakes-- they utilize air to release the parking brakes. Thus the yellow parking brake controller (which is nothing more than an air switching valve) sends air to the parking brakes to release them and bleeds the air to apply them. Not sure if that helps or hinders your diagnosis. I don't recall ever seeing one of those valves fail during my trucking days-- they are rather simple devices.

Norm

Wayne R · 01-25-2009, 04:35 AM

Mine acted up last summer after being parked for several months. I could hear a significant air leak. I rotated and pulled it in and out a few times and it returned to normal operation. I figured it was an O ring that was dry or slightly out of position. It has been working properly now the last 6 months. I plan on picking up a spare when I get somewhere to purchase one.

EngineerMike · 01-25-2009, 02:39 PM

Bill-
You should be able to remove the valve from the dash (I'd block the tires for a while IIWM) by pushing out the roll pin, & removing the jamb nut. It should back out of dash so you can read a part number. Haldex shows 3 push-pull valve choices on their website. Presumably you can call them to find a dealer near you. Let us know what the fix & part #'s are.

OldForester · 01-26-2009, 08:22 PM

Thanks for the input. I didn't see the roll pin e-Mike listed but I'll look for it when I have time. I at least want to carry a spare because I also think it's something like an o-ring or some other seal causing the leak. Rotating the yellow knob a bunch of time seemed to solve the problem. But it will be good to either carry a spare or replace it and use the old one as a spare (probably what I'll do).

I'll let the forum know the part number and the fix when I get to it. Too busy moving out of our old house this week and into our new custom house, and closing on both. Just need to fix it before our trip to Palm Springs in mid-Feb.

DR Dave · 01-27-2009, 02:08 PM

Mine did the same thing except after a while it started leaking all the time and could not apply the park brake . The switch would not move in or out.We have the vinal dash so remove top and heater vent on driver side.to expose valve two air lines to remove. Then rollpin on knob would not come out so I broke off knob.New vlave from ANYTHINGTRUCK.COM 31.00 + shiping.New valve does not have a rollpin It has a push pin much better.All fine now.

DR Dave · 01-27-2009, 02:13 PM

I forgot to say took old one apart.Found fine dand grit scared up seal and scored metal parts. Allso re used one plug and two 90deg. fittings for air lines.

DR Dave · 01-27-2009, 02:17 PM

PART NO KN20021 HALDEX

EngineerMike · 01-27-2009, 02:32 PM

Good reason to carry chok blocks at all times, JIC. (note to self- put chok-blocks in coach

)

OldForester · 01-29-2009, 08:01 PM

DR Dave -- thanks for the part number. I always carry 4 chok-bloks and use them a lot. Never know when that brake valve is not going to work. If I park on any kind of a downhill or uphill lie, I at least throw one in front or back of the front wheel.

I looked some more at the valve and talked to my dealer, who has installed a number of these valves and seen this problem a number of times on both Alpine and Holiday Rambler/Beaver coaches. He told me, yes there is air on the valve, and that there is a packing and nut over that packing underneath the yellow knob. The nut gradually works loose from the packing, faster on some than others. The recommended fix is to do exactly like Wayne and I did -- rotate the knob a number of times to help tighten the nut and packing and it should work fine, as it has done for both of us so far.

But I think it's a good idea to carry a spare valve, so I'm going to order one on DR Dave's part number and see how if fits as a spare.

OldForester · 05-09-2009, 06:09 PM

The parking brake switch kept leaking. It would leak as soon as the coach aired up and I started moving. I would push the brake switch in and out a few times, rotate it, and wait a couple minutes, after the air spitter valve opened a couple times, before moving and it would be OK. I finally got tired of doing this almost every time I started in the mornings, so while i was at the dealer having an error code 13 on my Dometic refer (drain heater element failed), repaired, I had him look at the switch.
'
He found a leaking fitting at an elbow on the swtich. He removed the fitting and hose, put new sealer on it, tested it and the leak has stopped. No problems since.

Thought I would post this fix in case others are having this annoying problem.