Brake activation
When the brake pedal is depressed, primary hydraulic pressure is generated in the floating caliper chamber, causing the piston to move in the direction of the brake disc. The moving piston comes into contact with the inner brake pad, causing the pad to move along the guide channels of the fixed support bracket and come into contact with the inside of the brake disc.
As the piston exits the caliper chamber, it passes through an internal O-ring located in the caliper chamber. Movement of the piston causes the seal to deform, and therefore the seal applies pressure to the outer surface of the piston.
The floating caliper now responds and begins to slide over the two bushed bolts in the opposite direction to the piston's extension. The floating caliper comes into contact with the outer brake pad, forcing the pad to move along the guide channels of the fixed support bracket and come into contact with the outside of the brake disc. The housing spring, which is connected between the fixed support bracket and the floating caliper, is tensioned when the floating caliper moves towards the brake disc.
When both brake pads are now in full contact with the brake disc and hydraulic pressure is applied to the piston, no further movement of the piston and floating caliper is possible. The force generated by the piston and caliper on the brake pads increases rapidly, clamping on the brake disc and slowing the car down.
Releasing the brakes
When the brake pedal is released, the hydraulic pressure in the caliper chamber drops and no more force is applied to the brake pads. The brake pads move outward slightly under the influence of the rotating brake disc and the inner caliper O-ring returns to its normal shape. As the seal moves, it grips the outer surface of the piston and draws the piston into the chamber just enough to provide the required clearance between the pads and the disc.
This action prevents the piston from holding the inner brake pad against the disc and also allows the piston to move further out of the caliper chamber to compensate for brake pad wear.
In the absence of pressure in the hydraulic system, the tension of the housing spring also decreases and the spring returns to its normal position. As the housing spring moves, the connected floating caliper moves away from the outside of the disc to provide the necessary clearance between the outer brake pad and the brake disc.
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