New to air brakes

[SBMF 2015]

I just acquired a GMC 9500. Tandem axle, 18' grain box, air brakes, 5spd manual w/ an Eaton 3spd, Detroit engine.
The previous owner is not mechanically inclined. Said there was something wrong with the brakes, but couldn't figure out what. He had a couple close scares two years ago hauling corn to the elevator, and not being able to stop at the stop signs. He just wanted it gone.
I brought it home and spent ten minutes, figured out that the front brake chamber on the passenger side tandem has a huge air leak.
If I cap the air line going to that chamber will the brake pads stay free or lock up? I know that's not the right way to fix it, but it sure would be a cheap way. Will the brakes on the other wheels still function properly?
Thanks everyone.

 

[Atimm693]

On most air releases the brakes. No air, brakes lock up.

But by your symptoms, I'd say that's not how yours are. It may have the older style that need air to work, and it may have just been running out of air.

 

[SmokinM]

If you are driving it on the road at all a new brake chamber is the cheapest and easiest way to fix it! No air should mean locked brakes. That is how your parking brake works is it blocks air flow and why you have to build pressure to move. Also check all your slack adjusters.

I will drive some hinky crap around but the brakes and steering parts are gonna be right and tight. Espescially on a vehicle like that.

 

[SBMF 2015]

On most air releases the brakes. No air, brakes lock up.

But by your symptoms, I'd say that's not how yours are. It may have the older style that need air to work, and it may have just been running out of air.

The pressure builds up past 120psi. I had my son push on the brake pedal and the pressure goes down quickly. You can run your hand around the brake chamber and feel the air coming out.

 

[cfpinz]

On most air releases the brakes. No air, brakes lock up.

But by your symptoms, I'd say that's not how yours are. It may have the older style that need air to work, and it may have just been running out of air.

The pressure builds up past 120psi. I had my son push on the brake pedal and the pressure goes down quickly. You can run your hand around the brake chamber and feel the air coming out.

Brake chambers are cheap, conjugal visits from the DOT are not. Neither are ER visits.

 

[SBMF 2015]

Had to run to town, so I took some pic of the bad air chamber and swung by the semi parts place.
After some research they decided that the truck has wedge brakes. They said parts are obsolete, if I can find some be prepared for the cost. I guess it's time to start googling for one.

 

[MurraysMutts]

Brakes are like BSE's....

 

[Silver]

If the brake pot has spring breaks it needs air to release it. If it is a single pot with no spring brakes then it doesn't. If it has spring brakes then you could cage it and block the air and limp it along.
But pots are cheap, diaphragms are cheaper. I'd rather not change a diaphragm so would buy the pot.