Q: How to inspect and service brakes, including checking disc brake pads, discs, brake lines, rear drum brakes, brake boosters, and parking brakes on 2012 Nissan Sentra?
A: Besides the aforesaid time intervals, the brakes should be checked if the wheels are off or, if there are signs that point out towards a defective brake system; the signs being the car pulls to a certain side when the brake pedal is depressed, squealing or dragging noise, very soft and long brake pedal travel, pulsating pedals or brake fluid leaks. Disc brake pads have specialized wear indicators which emit a high-frequency, squealing or scraping sound as soon as the pads are worn out to the level where the Contact, replacement is necessary as the discs can be damaged as a result. First, wrench the wheel lug nuts and thereafter, lift the vehicle properly on jack stands and detach the wheels. The caliper shall also have two pads located within and whether the lining material of the pads has dropped to the required minimum thickness that it has to be replaced. If it is hard to decide on the thickness, retract the caliper and pads and then clean with brake cleaner followed by a measurement. Check the thickness of the disc with a micrometer, replace any disc that is less thin than the standard required and this is also the time to check discs for scoring and gouging. All brake hoses and lines must be checked for damage, scores, crack, wear and leakage; the ends should also not have contact with sharp edges or any moving parts and if compromised; they must be repaired or replaced. Can only inspection be done on rear drum brakes through the removal of the brake drums and measuring the thickness of the lining material and replacing the shoes if they have cracks, glaze, or abrasion. Investigate the condition of the shoe return and hold-down springs and look for any kinds of leakage on the wheel cylinders, Also check the drum for the finish that cannot or should not be polished with the emery cloth but has to be resized. Having put on the brake drums and wheels, tighten the nut screws to the recommended torque. The check on the brake booster involves the following tests done by the driver while sitting on the driver's seat, the tests are on the operation of the pedal during the start of the engine, several depression of the pedal, and after switching off the engine. If at all the brakes do not function as they should during these tests, it might be time to replace or fix the brake booster. As for the parking brake, take a set and count the click if it is not adjusted, or engage on a high gradient to check if the car won't roll on the slope.