Symptoms Of A Bad Air Brake Chamber: Easy Fixes!

Air brake chambers sometimes may make mechanics confused. The elements can resemble secret passages. Sometimes a faulty air brake chamber or air in brake line can cause brake failure. But before this, there are specific symptoms. So what are the symptoms of a bad air brake chamber?

Push-rods twisted, corroded, or dented visually impair the chamber are signs of a faulty chamber. Contaminants like water and dirt can enter the chamber through broken dust plugs or slack ring clips. Other problems include the push-rod detracting issue, the hot wheel, and the DOT warning.

Commercial trucks like Freightliner or International require air brake chambers as a critical component. Explosions and other hazardous situations may result from a malfunctioning air brake chamber. So be careful and gain some in-depth knowledge!

Bad Air Chamber Symptoms

There are some upkeep concerns to resolve despite the development of air brake chambers. Here are five key symptoms of a bad air chamber and solutions.

1. Push-Rod Retracting Problem

It typically occurs when the slack regulator is the incorrect height, or the brake chamber is most probably put on the faulty hub mounting slots.

The push rod gets trapped in the slot every time it is extended since the alignment was not exactly 90 degrees. The warranty bin has evidence of that problem. The chambers show proof that the push rod tore the servicing housing.


A 90-degree angle should be used for the adjustment. The distance between the camshaft’s center and the clevis pin serves as the slack adjuster’s arm span measurement.

Some providers have introduced larger holes and Teflon or plastic discs to remedy this problem. However, it still does not guarantee the ideal 90-degree angle.

2. DOT Warning

The air brake chamber gives DOT warning when the push rod length is wrong.

Fleets may discover that brakes are not effectively setting and releasing the same shaft after a brake chamber replacement. Or perhaps the wheel end is overheating. A mismeasured push rod length is the root of this problem.


Everybody has a unique method for calculating the push rod’s length. But out of all the available push rods, there are usually only three length options.

The length from the top is restricted to 2.25 inches, except for lift axles. Trailer suspensions come in 5.75-inch widths, whereas Intraax suspensions come in 9.75-inch widths. The length of the push rod at 90 degrees will serve as the only reference point for cutting the lift axles.

3. Hot Wheel

Misaligned brake chamber strokes throughout the same axle may cause the wheel end to be constantly hot following a brake chamber replacement. Additionally, it will lead everything to move to one side while applying the brakes.

Perhaps a long stroke and a standard stroke are seated next to one another. Check the suspension and If your vehicle is commercial like Mack or Peterbilt, Eibach or Bilstein suspension is not enough.


Although you can adjust the length, you should always install matched pairs.

The air system can be slowed down by up to six feet of extra hose by attaching a 90-degree connection to the service portion of the chamber.

4. Chamber And Slack Adjuster Adjustment Problem

Ensure that the proper clevis was used if a Meritor trailer slack adjuster was attached. The spacing varies depending on the type of slack adjuster.

Since the sizes are not significantly different, the wrong selections can still be manually inserted.


Reinstalling the ASA and fully twisting the adjustment screw are the solutions. But there is also a trade secret at play here.

TSE Brakes suggests turning off the adjuster screw by 3/4 of a turn instead of 1/2 since mechanics frequently use more extensive tools. The ASA will then find the proper working limit by applying the brakes 12 times.

5. Push-Rod Bent Problem

Another sign of a malfunctioning air brake chamber is a bent push rod. Push-rods bent on brake chambers typically measure 9.75 inches in length.

The slack adjuster is to blame in this situation. An old slack adjuster which has stuck and won’t spin is the cause of the issue.


To fix this problem, you must replace the Slack adjusters. The brake chamber must also be replaced.

How To Replace Bad Air Chamber?

The average lifespan of the air chambers ranges from two to four years, based on the working conditions and how frequently the vehicle is utilized.

Here are the procedures to follow when it’s time to replace your brake air chamber:

Step 1: Buy New Air Chamber

It is ideal to choose a new chamber that is a replica of the old one. There are several sizes for brake chambers. They can also be divided into short and lengthy strokes.

Determining the amount of slack adjuster utilized in the brake system is vital for anyone servicing a drum brake. Additionally, it’s critical to check that the fastening holes on the mounting bracket line up with the notches on the chamber.

Step 2: Preparing The Vehicle

Keep yourself secure when working on the braking chambers of your truck. When accidentally released, the primary spring has enough strength to damage or destroy body parts.

So, you should always remove the legal truck wheel spikes to keep yourself secure, if you use them in your truck. Keep a heavy-duty floor jack closer to your truck and never forget to hire a trucker to assist you.

When maintaining the air chamber on your truck, stay away from halogen lamps, welders, and hefty tools. Parking the car in a level area will make it easier for you to halt the axles and apply the parking brakes.

Step 3: Remove The Bad Brake Chamber

Remove the chamber caging equipment from the rear of the brake chamber using a standard 34-inch wrench. Take the rod pins from the collet pins to remove the slack adjuster.

Two mounting nuts connect the axle’s bracket and the braking chamber. You can use a 15/16-inch wrench to remove these nuts. The cage tool must be removed by turning it counterclockwise.

Step 4: Install New Brake Chamber

Wipe the fastening surfaces and ensure they are damage-free after removing the old chamber. To ensure that it won’t exert any stress on the push-rod throughout installation, verify to see if the main spring of the fresh chamber is trapped.

Attach the new chamber against the frame and fasten it with the fastening bolts. Use the brackets that arrive with the new chamber, even if the old one still looks okay.

Step 5: Link Chamber With Air Supply

It’s time to connect the chamber to the air supply once the chamber port has been appropriately positioned. Compress the chamber after clicking the airline and making the connection.

Using a solution of soapy water and fittings, you should inspect for leakage. Release the air from the chamber and adjust the brakes to the proper stroke only if you are confident that the connections are leak-free. Then you have to link the other components as well.


Many times, early indications of deteriorating air chambers go unreported. All other brakes will continue to function correctly. So that this issue can go unnoticed until it becomes severe enough to lead to brake chamber problems.

Hopefully, we covered everything in detail about the symptoms of a bad air brake chamber. One of the damaged components inside may be the source of the problem. Early problem detection might help you steer clear of any mishaps. So drive safely and with thorough knowledge!

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