A heavy-duty truck with a cam-style air brake system exhibits uneven braking across the drive axles. The technician notes that one brake chamber's pushrod stroke is significantly shorter than the others. What is the most likely cause for this observation?

Question: A heavy-duty truck with a cam-style air brake system exhibits uneven braking across the drive axles. The technician notes that one brake chamber's pushrod stroke is significantly shorter than the others. What is the most likely cause for this observation?

Answer options: ✅ A seized slack adjuster on the affected wheel end.

• An over-adjusted brake on the affected wheel end.
• A faulty quick release valve at the affected wheel end.
• Insufficient air pressure reaching the affected brake chamber.

Correct answer: A seized slack adjuster on the affected wheel end.

Explanation: A seized slack adjuster prevents proper application of the brake shoes, resulting in a shorter pushrod stroke because the slack adjuster cannot extend fully. An over-adjusted brake would typically result in a shorter stroke but would also lead to dragging, which is not implied here. A faulty quick release valve or insufficient air pressure would generally affect the stroke length (either longer due to delayed release or shorter due to less force) but a seized slack adjuster is a classic cause of uneven braking and short stroke.