My air brakes are locked!

barth wrote:
I will go and try to hit the drum with a hammer. Do you have to release the brakes before you hit the drum, or do you do that with the brakes on?
Thank you for your input

Didn't read my post

mdamerell wrote:

barth wrote:

okgc wrote:
I know of a case where the air line for the parking brake had been chewed by mice so there was no air pressure to release brakes.

I'm a bit confused. Are saying that there is two braking system? The regular one and the parking one?
If there is only one system, then my air pressure is up and steady. One weel wants to move while the other one doesn't

Yes, there are parking brakes and service brakes. If you look at your rear axle there should be two chambers. One contains a massive spring to apply the parking brake. The other is the service brake. It normally takes about 30# of air to compress and hold it out of the way. If you look at your steer axle there is only 1 chamber on each wheel (service brake)

Air Brake pump down procedure

I'd try backing up 1st, then tap the metal part of the brake shoe with a hammer to bust it loose. Common on a truck that's sat.

But ONLY ONE SET OF BRAKE SHOES! Don't confuse the issue.

barth: This is a good explanation of the air brake system and how the spring brakes work.
Air Brake chamber

JetAonly wrote:
This is common if you don't do a pneumatic system test. You know…. the one you are supposed to do each day before you operate an air brake vehicle.

Yes I do the daily check when I use it. We are talking about releasing the brakes after 6 months of storage.

I didn't know this was a fairly common problem.

Daily leak down will not prevent shoes seizing during long term storage ,try not setting the brake for long term storage just chock the wheels next time.
They will eventually gently come to rest against the drums at a equal temp ,should help .

This is common if you don't do a pneumatic system test. You know…. the one you are supposed to do each day before you operate an air brake vehicle.

I will go and try to hit the drum with a hammer. Do you have to release the brakes before you hit the drum, or do you do that with the brakes on?
Thank you for your input

barth wrote:

okgc wrote:
I know of a case where the air line for the parking brake had been chewed by mice so there was no air pressure to release brakes.

I'm a bit confused. Are saying that there is two braking system? The regular one and the parking one?
If there is only one system, then my air pressure is up and steady. One weel wants to move while the other one doesn't

Yes, there are parking brakes and service brakes. If you look at your rear axle there should be two chambers. One contains a massive spring to apply the parking brake. The other is the service brake. It normally takes about 30# of air to compress and hold it out of the way. If you look at your steer axle there is only 1 chamber on each wheel (service brake)

Air Brake pump down procedure

I'd try backing up 1st, then tap the metal part of the brake shoe with a hammer to bust it loose. Common on a truck that's sat.

I used to be an otr truck driver. We would have this happen if we put the brakes on the trailer. We just took a hammer an hit the drum until it would break free.

Happens on fire trucks I drive. Just but in reverse and back up about a foot brakes should then release.