Air leaks from parking break knobs

staceydude · Apr 23, 2022

The reason it sounds like it is coming from the brake valves inside the cab is air is rushing through the system to a leak somewhere.

Take a stick or have someone hold your brake pedal down and go around and listen for leaks.
I have a brake line on one of my chambers take a hit from something and broke the fitting. It sounds just like the valves in cab are leaking but again just air rushing through the system.

Ikamob01 · Apr 24, 2022

Lennythedriver said: ↑

The knobs don’t leak, if you hear air rushing sound through the knobs it’s 99 to 1 and air leak somewhere else. Usually a brake chamber. Very often the brake chamber hoses are zip tied with other hoses some of which are wrapped in a plastic chafed protective barrier which will eventually rub its way through one of your air chamber hoses. If that’s the case, you can get sone rubberized tape that is made specifically for that purpose, but it’s just to get you back to the yard or to get it fixed. Or you can use a heavy duty pair of vise grips to cramp off the cylinder that’s leaking or the hose. Zip ties will work as well. If you do that, you’ll be down one brake, but it’s no big deal if you’re going to get it fixed.
Click to expand...

You are a complete Genius and smart dude.

Lennythedriver said: ↑

The knobs don’t leak, if you hear air rushing sound through the knobs it’s 99 to 1 and air leak somewhere else. Usually a brake chamber. Very often the brake chamber hoses are zip tied with other hoses some of which are wrapped in a plastic chafed protective barrier which will eventually rub its way through one of your air chamber hoses. If that’s the case, you can get sone rubberized tape that is made specifically for that purpose, but it’s just to get you back to the yard or to get it fixed. Or you can use a heavy duty pair of vise grips to cramp off the cylinder that’s leaking or the hose. Zip ties will work as well. If you do that, you’ll be down one brake, but it’s no big deal if you’re going to get it fixed.
Click to expand...

Anywhichwaybutloose · Apr 24, 2022

A bad tractor protection valve could be the issue.

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