My park brake "yellow button" on the dash would leak some times until I turned it a little bit. I could make it leak by pushing the knob down or up or to the side. Very noticeable leak. I removed it, cleaned it, polished the inside, and greased it after replacing the very worn "O" ring. Easy job which only cost a few pennies because I carry a full "O" ring suitcase. Now I cannot even make it leak.
Dismantling requires forcing out a pressure pin (holds yellow knob on shaft) which I replaced with a stainless flush nut bolt for easy removeal.
Thank you. Good info.
Strange this showed up. I fought this on the 800 miles home last week from NM. If it did like mine, it would leak quite a lot, I had to press it back in to quit trying to take it into park. Then try again, and usually it would hold without air cooling me. MOT took the thing apart, found that contrary to what they had seen before, it was plastic. They found, what they told me was typical, a metal one through a truck supply.
Perhaps it only needed an new o-ring. Do not know, but I was told about replacing it with a better one. Mike
Wyatt,
I had the same problem with my dash control park brake leaking down overnight. I found your post on the "fix" and followed your instructions for removal. I also found a repair kit made by Haldex Midland part# 281126k - valve repair kit at Heavy Duty Truck Parts Online, Brake Parts, Light & Medium Duty Truck Parts, (http://www.finditparts.com/#/search?utf8=%25E2%259C%2593&per_page=20&s=281126k). It has both "O" rings and the other parts for a complete rebuild. Easy to replace and reinstall and I believe its not leaking anymore. I did find another leak underneath by the steering column where the 60psi pressure switch is mounted to a "T" connection on the air lines. I tightened the small bolts where it connects to the "T" and I believe the leak is gone. It's easy to get to and the photo shows where it is. Pierce Stewart told me that a leakdown of 10psi overnight is okay and hopefully this will do the trick.
I still need to get a stainless flush nut bolt for the knob to complete the job.
These kinds of DIY repairs build confidence in non mechanics like me and is made possible with the shared knowledge of the generous members of this great forum and is Karma worthy to me!
Thanks,
Jerry
Here's the pic of the leaking 60 psi pressure switch that didn't show up on my last post. Look for the cluster of air lines next to the steering column underneath.
Jerry