Filling Brake Master Cylinder Reservoir

The master cylinder reservoir must be kept properly filled to insure adequate reserve and to prevent air from entering the brake hydraulic system. However, because of expansion due to heat absorbed from the brakes and from the engine, the reservoir must not be overfilled. A drop in brake fluid level is normal as the pads wear. Filling the master cylinder reservoir before installing new pads may result in brake fluid spillage once the new pads are in place. Unless there is a leak in the brake hydraulic system, or if the brake hydraulic system has been serviced, topping off the master cylinder reservoir should not be necessary. Thoroughly clean the master cylinder reservoir cap before removal to avoid getting dirt in reservoir. Remove reservoir cap and reservoir diaphragm. Add brake fluid to bring fluid level to line located inside the neck of the reservoir fill opening.