Wilwood Thermlock Caliper Pistons provide an effective thermal barrier for minimizing heat transfer from the brake pads to the caliper body, seals and fluid. The innovative multi-part design incorporates a stainless steel shield and coated aluminum shell configuration that effectively retards heat transfer by at least 25 percent. The reduction in operating temperature eliminates seal crystallization and localized fluid boiling, extending the overall service life with decreasing distortion in the caliper body and piston bores.

Wilwood Thermlock Caliper Pistons were originally developed for the extreme temperatures and sustained high heat in NASCAR and road racing. Thermlock pistons are available as current service replacements or as upgrades in any stainless steel piston equipped or older model calipers.