Trying to get to my Nacogdoches appointments and our brake valve "hung up" at startup. The hissing stops when the service brake is fully applied, but continues to leak air when the pedal is released. I pulled the part tag while muttering bad words: "Midland N4506A 254K"
Here's a photo of the part. Checking Haldex sites, the valve is obsolete. Of course, FOT and NAPA are closed now. Argh! My plan is to search for the part unless there is a safe work-around until I get to FOT.
Any ideas? Thanks. Paul
Paul,
Is that the valve mounted high in the center rear of the front axel bay?
Is it cold where your are? If so maybe heat from a drop light over night may help?
Just a thought.
John,
Yes, front and center, just aft the wheels. The lamp idea is easy. It's cool here in New Braunfels, but not blowing cold like I've been watching on the Forum. Thanks. P
If warming does not work, try some light "percussive" persuasion.
Brett, John and Fellow Fo'Fums--We made the trip to Nacogdoches this evening after a few sessions under the Beast with a lamp/billy club and some classic Good Cop/Bad Cop routines out of Dragnet.
We wailed on it pretty gently at first, played the service brake whilst doing rhythms right out of the 70's. The valve's slide loosened up a bit and quit hissing almost when I released the brake. More drumming with less gentle interrogation and the valve started to operate as designed. Backed out and tested for a bit with no problem. 275 miles later, we're at Camp Foretravel with a pretty big crowd of good-looking coaches!
Thanks, Guys. I hope Tomorrow we can get some real magic performed on the old girl's air brake system at FOT.
Please post what your outcome is.
I had posted about a mystery air part on my coach months ago, your problem is my problem as I see the same part in your pictures that I have leaking air.
Paul,
If the other ideas do not work, you might try bleeding all of the air pressure off, then remove the pressure
line(s) going into the valve. Then spray a lubricant (that will not damage plastic) into the valve, then replace
the supply line and build up air pressure and apply Brett's advice. If this does not get you to Nac we will
hunt up a chain and come to rescue you.
Hope it helps,
Carter
Nac-