What Is a Thermlock Piston?
Just about every car person understands the importance of braking system maintenance. Some even know about brake calipers and that heat built up under extreme braking situations lowers braking performance. However, few people know about Thermlock pistons and their role in high-performance braking systems.
What are the main parts of a typical braking system?
Firestone breaks down the two most common braking system types – drum and disc – into the major components associated with each. While there are similarities between the two system types, our focus here is on the more modern and increasingly common disc brake style system. Here’s a list a short description of the major components of a typical braking system:
- A master cylinder pressurizes the brake system when pressing the brake pedal.
- Brake boosters put the power in “power brakes.”
- Brake fluid is the lifeblood of the brake system. It hydraulically transfers power from the master cylinder to the brake calipers.
- Brake lines carry brake fluid throughout the system.
- Brake calipers use brake pads to apply pressure to the brake rotor.
- Brake pads contain a friction material designed to rub against the metal brake rotor without causing damage.
- Brake rotors attach to the wheel hub assembly and rotate at the same speed. Activating the braking system causes the brake calipers to squeeze the brake rotors between the brake pads to slow the rotation.
What do brake caliper pistons do?
The pistons inside a brake caliper transfer the brake fluid’s hydraulic pressure to the brake pad. Placing your hand near a brake rotor immediately after an extreme braking event will let you feel a sample of the heat generated from braking. As the pads heat up, heat transfers through the caliper’s pistons and leads to many problems, such as:
- Distorted brake calipers
- Seized caliper pistons
- Localized brake fluid boiling
- Loss of brake pedal “feel”
- Reduced stopping power
MotorTrend says high-performance braking systems allow peace of mind, whether on a racetrack, getting cut off in traffic, or negotiating steep downhill grades. TCE Performance Products is one supplier of specialty brake system kits featuring brake calipers with Thermlock pistons. Another option for Shelby Mustang owners is the Shelby Store.
What role do Thermlock pistons play in high-performance braking systems?
Wilwood says Thermlock pistons initially found fame in braking systems designed for NASCAR and other professional racing circuits. Thermlock pistons combine stainless steel and aluminum to reduce heat transfer from brake pads to brake calipers by at least 25%. This reduced heat transfer improves performance in all situations.
Should I buy high-performance brakes for my vehicle?
While every vehicle with factory braking systems performs adequately, they would all benefit from improved brake system components. However, most people will never exceed the limits of their vehicle’s stock system. So, it isn’t easy to justify the expense of a high-performance system or adding Thermlock pistons.
The exception lies with vehicles modified for performance and those hauling heavier than normal loads. In these cases, the cost of improved braking systems should reflect a portion of the money invested in going faster or carrying more.
