CDL Air Brakes TestInspecting Air Brake SystemsHard
A driver is performing a pre-trip inspection and notices that a brake chamber on one of the drive axles has a significant bulge in its diaphragm. What action should the driver take?
- ADrain the air tanks to relieve pressure and then re-inflate.
- BContinue driving, but monitor the air pressure closely.
- CAdjust the slack adjuster on that wheel to compensate for the bulge.
- DImmediately take the vehicle out of service and arrange for repair.
Show answer & explanationAnswer & explanation
Correct answer: D. Immediately take the vehicle out of service and arrange for repair.
A bulge in a brake chamber diaphragm indicates a severe compromise in its integrity. The diaphragm is critical for converting air pressure into mechanical force to apply the brakes. A bulge means it could rupture at any time, leading to sudden loss of braking ability for that wheel, making the vehicle unsafe to operate. It requires immediate repair.
Why the other options are wrong
- A. Draining and re-inflating air tanks will not repair a damaged diaphragm and is irrelevant to this specific problem.
- B. Continuing to drive with a damaged brake chamber is extremely dangerous and could lead to brake failure.
- C. Adjusting the slack adjuster will not fix a damaged diaphragm and could mask the underlying critical issue.
Brake Chamber Diaphragm
A flexible rubber membrane inside the brake chamber that moves the pushrod when air pressure is applied, activating the brakes.
- Essential for converting air pressure to mechanical force.
- Any damage (bulges, tears) compromises braking.
- Must be intact for safe operation.
Memory trick: Bulge in the chamber, means danger's in amber!