StopTech 42.200.1007 Anti-Knock-Back Spring for 26-36mm Pistons 4lb Force

The StopTech 42.200.1007 is a precision-engineered anti-knock-back spring designed to solve brake performance issues in high-performance and racing applications. This spring is specifically sized for brake caliper pistons ranging from 26mm to 36mm in diameter and provides 4 pounds of force to maintain consistent brake pedal feel.

What It Does:

Anti-knock-back springs install behind the caliper piston in the bore and apply light pressure to keep brake pads in contact with the rotor. During aggressive cornering or driving over rough surfaces, suspension deflection can push pistons back into the caliper body, creating a gap between pad and rotor. This results in a long pedal stroke and delayed braking response on the next brake application. The StopTech spring prevents this condition by maintaining constant light pressure on the piston.

Key Features:

• Fits caliper pistons 26mm to 36mm in diameter
• 4 pounds of spring force
• Eliminates long pedal travel caused by pad knock-back
• Reduces the need to pump brakes before braking zones
• Installs behind piston in caliper bore (sits in brake fluid)
• Sold individually - order one per piston
• Ideal for track, racing, rally, and performance street applications

Applications:

Compatible with StopTech performance brake calipers and other aftermarket calipers with piston diameters in the 26-36mm range. Particularly beneficial for vehicles experiencing pad knock-back due to track use, racing over curbing, or aggressive street driving with performance brake systems.

This is a single spring - multiple springs are required for a complete caliper installation (one per piston). StopTech springs are manufactured to precise specifications to ensure consistent performance and durability in demanding brake system applications.