air brake emergency knob

[EPeterman]

I am a problem with the emergency pRK KNOb COMING ON when using the parking brake stopped in traffic when I release it the air pressure goes below 60 and it comes back on, then I have to build pressure backup in order to move . Any clues for an easy fix or is road service the best place to start.

[CA_Traveler]

Probably over tightened.

[EPeterman]

Air problem resolved, Cracked brass reducing fitting,cracked perpendicular to the threads, very unusal to say the least only cost was new fitting and labor, works great. Repair made at West Branch Diesel, West Branch, Mi

[vegasfoodguy]

EPeterman wrote:
I am a problem with the emergency pRK KNOb COMING ON when using the parking brake stopped in traffic when I release it the air pressure goes below 60 and it comes back on, then I have to build pressure backup in order to move . Any clues for an easy fix or is road service the best place to start.

You should do the air brake test (Most dmv class 1 license books, explain it).

[Terryallan]

OR maybe your applied air setting is too low. It should normally run at 120 PSI.
Are you using the park brake in traffic, or is it drawing in when you release the foot brake?

[Big_Katuna]

Sounds like you have a serious air leak. You should not lose pressure when the engine is running. The system should hold pressure several hours with the engine off.

[CA_Traveler]

OP, Get it fixed. This is a public forum and it's not advised to post your email address.

[azpete]

are you saying you use the emergency park brake in traffic? or just in long backups and construction?

[memgrove]

You have an air leak that must be repaired to operate the rig safely.

[dakdave]

Why use parking brake in traffic? Does air drop if you use service brakes? It should not,if it does you have air leak.Releasing parking brake should drop air pressure very little.Take it to a truck repair shop and have it checked before you cause an accident