The front brake pads have built in wear indicators that contact the brake disc when the brake pad thickness becomes too thin and emit a squealing sound to warn the driver.
Inspect the thickness of the brake linings by looking through the brake caliper body check port. The thickness limit of the lining is 0.08 in. (2.0mm) except on 1995–98 626, MX6, Millenia. On 1995–98 626, MX6, Millenia, the limit is 0.04 in. (1.0mm).
When the limit is exceeded, replace the pads on both sides of the brake disc and also the brake pads on the wheel on the opposite side of the vehicle. Do not replace just one pad on a side without replacing the other pad on the same wheel as well as the brake pads on the other front wheel.
If there is a significant difference in the thickness of the pads on the left and right sides, check the sliding condition of the piston, lock pin sleeve and guide pin sleeve.