A wedge brake chamber packs the power and force in your braking system when you apply the brakes. It's a critical part of the truck braking system that must be safe sealed and reliable.


Torque imbalance, or lack of uniform friction-material to friction-surface contact, can diminish brake stopping power. Oil or grease on the pad or shoe, glazed friction material, polished drums or rotors, linings or pads with mixed friction capabilities at one or more wheels and improperly spec'd axle gross vehicle weight rating all can contribute to brake imbalance problems.

Pneumatic imbalance, or varying air pressures delivered to tractor-trailer combination vehicles, can also degrade brake response. It can happen due to a variety of causes, including inoperative or maladjusted antilock brake wheel sensors, incorrectly spec'd axle gross vehicle weight ratings and improperly installed automatic slacks.

Self-energizing or rotating a primary shoe against a drum can help increase shoe-drum friction and produce more effective braking. A cam rotates to force the primary shoe against the drum, depending on which direction the drum is rotating. The left-hand cam rotates counterclockwise and the right-hand cam turns clockwise.

In a self-energizing system, the primary shoe will apply "harder" or "bite" into the drum, increasing friction and producing more effective braking. However, self-energizing can also cause uneven brake shoe wear and poor shim adjustment. If this is the case, your brakes may require frequent adjustments to achieve balanced braking. It's better to avoid self-energizing systems unless the braking system is rated for it.