Brakes Exam Questions All 100% Correct Answers

Brakes Exam Questions All 100% Correct Answers On a car with disc/drum brakes, the front brakes grab quickly when light pedal pressure is applied. This problem could be caused by a bad: A. proportioning valve B. pressure safety switch C. metering valve D. residual check valve - C. The metering valve delays the flow of brake fluid to the front calipers until the pressure in the system rises to a point where the wheel cylinder can overcome the tension of the brake shoe return springs. The purpose is to have both front and rear brakes apply simultane ously. This prevents the front brakesfrom locking up during light brake applications. The driver of a vehicle with power disc/drum brakes says that the brake pedal moves slowly to the floor while maintaining pedal pressure at a stoplight. What could cause this problem? A. leaking primary piston cup in mast cylinder B. leaking power brake booster 2 | P a g e Author: Katelyn Whitman. ©2025, All Rights Reserved. C. leaking residual check valve in master cylinder D. internal leak in the combination valve - A. If the primary piston cup in the master cylinder is leaking pressure will not build up ahead of the primary piston to increase pressure to the rear brakes. The piston will then move forward until the spring is compressed enough to move the secondary piston. Consequently, this internal leak will cause the brake pedal to slowly drop to the floor. Which of the following would MOST LIKELY happen if the measurements taken from the check shown above varied from the manufacture's specifications? A. noisy brake operation B. brake grab or pull C. pulsating brake pedal D. low brake pedal - C. Poor rotor parallelism (thickness variation) will cause a pulsating brake pedal. This is due to the caliper piston movement that occurs as the pad rides over the alternating high and low areas on the disc. This action forces brake fluid to flow back and forth from the caliper to the master cylinder, creating the pulsating pedal feedback. What is the purpose of the master cylinder residual check valve(s) on vehicles equipped with drum brakes? A. allows the driver to pump up the brakes 3 | P a g e Author: Katelyn Whitman. ©2025, All Rights Reserved. B. prevents air from entering the hydraulic system C. prevents wheel lockup by reducing the hydraulic pressure D. reduces pedal pulsation by controlling hydraulic pressure - B. Residual check valve(s) are used on drum brakes to keep residual low pressure (slight static pressure) in the brake system at all times even when the brake pedal Is released. This pressure (5- 20 psi) keeps the lips of the wheel cylinder piston cups tight against the cylinder walls to prevent air from entering the system when at rest (brakes released). A tech has just overhauled the front brakes on a vehicle with front disc and rear drum brakes. However, when he attaches a pressure bleeder (pressurized to about 25 psi) to the master cylinder, he cannot get any fluid to come out of the disc brake caliper bleeder screws. Which of the following is MOST LIKELY the cause? A. bad proportioning valve B. bad pressure differential valve C. proportioning valve release button not activated D. metering valve released button not activated - D. A metering valve requires a minimum pressure (typically between 75-125 psi) to open. At this point pressurized fluid Hows to the front calipers. Since the bleeder tank is only pressurized to 25 psi, fluid pressure is too low to open the metering valve during this procedure. Therefore, when you use a pressure bleeder on a system with a metering valve, you must 4 | P a g e Author: Katelyn Whitman. ©2025, All Rights Reserved. manually keep the valve open by either pushing the button in on the end of the valve, or pulling the stem outward on the end of the valve. On a vehicle with single piston floating caliper front disc brakes, the brake pads on the left side of the vehicle are almost completely worn while the right side is almost new. Tech A says that too much rotor runout could be the cause. Tech B says that a binding caliper piston could be the cause. Who is right? A. Tech A B. Tech B C. Both D. Neither - B. Excessive rotor runout would cause a pulsating brake pedal, but not uneven side-to-side pad wear. A frozen caliper piston on the other hand, will keep both inner and outer brake pads equally applied against the rotor even when the brake pedal is released. This constant friction will cause rapid pad wear in the affected caliper as well as a front-end pull. What is the purpose of the bar that is being removed from the brake assembly shown below? A. to equalize the braking force between the shoes during normal braking B. to center the shoes after each brake application C. to force the shoes into the drum when the parking brakes are applied 5 | P a g e Author: Katelyn Whitman. ©2025, All Rights Reserved. D. to reduce the distance between the shoes and the drum - C. The parking brake strut bar forces the brake shoes into the drum when the parking brake is applied. A hydraulic brake line is leaking. Which of the following is the correct repair procedure? A. Cut out the bad section and replace the new steel tubing using compression fittings. B. Replace the leaking line with double-flared, seamless copper tubing. C. Cut out the bad section and replace with single-flared steel tubing using flare nuts and unions. D. Replace the leaking line with double-flared steel tubing. - D. Steel tubing of the same size, type, and length with double flared ends must be used when replacing a traditional SAE double inverted flare style hydrau lic brake line. The set-up shown above is used to check