Brake Problem Questions
After honing a brake caliper, the maximum allowable increase in caliper bore diameter is: A. 0.001 in (0.025 mm). B. 0.002 in (0.050 mm). C. 0.005 in (0.127 mm) D. 0.008 in (0.043 mm).
0.001 in (0.025 mm). (A caliper bore should never be increased by more than 0.001-inch. Any more than that may allow the piston to move on an angle and get stuck in the bore)
The parking brake cable should be adjusted with the parking brake on one click so there will be a slight drag in the wheels. (When adjusting the parking brakes on a vehicle equipped with rear disc brakes, the parking brake cable should be adjusted with the parking break on one click so there is a slight dragi n the wheels.)
0.25 in (6.35 mm). (On most cast iron master cylinders, the brake fluid level should be 0.25 inch (6.35 mm) below the top of the casting surface.)
There are signs of paint removal and peeling on the power brake booster right below the master cylinder. The cause of this could be: A. A leaking secondary cup on the primary piston. B. A defective diaphragm in the brake booster. C. A leaking secondary cup on the second piston. D. Fuel being drawn into the booster by the vacuum.
A leaking secondary cup on the primary piston (A leaking secondary cup on the primary piston could cause an external leak at the master cylinder. Because brake fluid tends to destroy paint, the peeling paint could be a good indication of a brake fluid leak.)
The brake pedal is low and spongy; all brake adjustments have been completed according to specifications. The cause of the problem could be: A. Binding pedal linkage. B. Dented brake line. C. Plugged compensating port. D. A weak hydraulic hose
A weak hydraulic hose. (Binding pedal linkage would cause a hard pedal and perhaps an effective brake system. This is also true for a dented brake line. A plugged compensator port may cause dragging brakes. A weak hydraulic brake hose could cause a spongy pedal. As the pressure builds in the system, the hose may expand and not relay the pressure to the brake units.)
While discussing brake backing plates, Technician A says a bent backing plate may cause brake grabbing. Technician B says a loose anchor bolt may cause brake chatter. Who is right? A. A only B. B only C. Both A and B D. Neither A nor B
B only (Brake chatter may be caused by improper brake adjustment; loose backing plates; contaminated brake linings; out-of-round, tapered, or bell-mouthed drums; cocked or distorted shoes; or loose wheel bearings.)
A vehicle experiences brake squeal during brake application. Technician A says the drums may be distorted. Technician B says the backing plates may be bent. Who is right? A. A only B. B only C. Both A and B D. Neither A nor B
Both A and B (Both technicians are right. Brake squeal may be caused by bent backing plates, distorted drums, loose linings, improper position of the linings on the shoes, weak or broken hold down springs, or loose wheel bearings.)
While reassembling a brake caliper: A. The boot should be installed and seated, folloed by the seal. B. Coat the piston seal and boot with clean brake fluid. C. Leave the piston dry and install it through the boot and seal until it bottoms. D. Plug the bleeder screw hole and the high pressure inlet while installing the piston.
Coat the piston seal and boot with clean brake fluid (While assembling a brake caliper, coat the piston seal and boot with clean brake fluid. Do not attempt to install the seal after the boot has been installed. Also do not attempt to install a dry piston through the boot.)
When removing the master cylinder, all of the following steps must be performed EXCEPT: A. Relieve any vacuum boost pressure (if equipped with power brakes). B. Plug the ends of the brake lines to prevent fluid loss. C. Disconnect the float level sensor. D. Drain the master cylinder.
Drain the master cylinder. (All of the answer choices need to be completed prior to removing the master cylinder. Draining the master cylinder of fluid is not something that must be done. If it is done thef luid is removed only after the lines have been disconnected and capped. Fluid should not run out of the master cylinder while it's being removed so it is easier to empty the cylinder on a bench.)
To test the brake warning light circuit: A. Drain the master cylinder, start the engine, and watch for the warning light to illuminate. B. Disconnect the switch, start the engine, and apply moderate brake pressure. C. Replace the switch because it may be faulty. D. Ground the warning switch wire with the ignition on.
Ground the warning switch wire with the ignition on (All of the answers are wrong except D. An easy way to check the operation of the brake warning light circuit is to disconnect the wire to the switch and temporarily ground it. If the circuit is fine, the lamp will light when grounded. This is what the switch should do when it is working normally.)
All of the following statements are true about brake drum inside diameter measurements with a brake drum micrometer EXCEPT: A. The drum should be cleaned before measuring the diameter. B. If the drum diameter is less than specified, replace the drum. C. The diameter should be measured at two locations around the drum. D. The drum diameter variation should not exceed 0.035 in (0.009 mm).
If the drum diameter is less than specified, replace the drum. (In this except-type question, all of the statements are true except B. If the inside diameter of a drum is less than specifications, it should not be replaced. IN fact it is fine providing the shoes fit inside the diameter.)
During a surge bleeding procedure: A. The end of the bleeder hose must be kept above the level of the fluid in the container. B. Pump the pedal quickly several times with the bleeder screw closed. C. Pump the pedal quickly several times while opening the bleeder screw. D. Decrease the pressure bleeder chamber pressure to 10 psi (69 kPa)
Pump the pedal quickly several times with the bleeder screw closed (In order to move the air that may be trapped in the brake system, pressure must be built up to force the air out when the system is opened. The other answers relate to pressure bleeding, not surge bleeding, or would allow air to enter the system during the bleeding process.)
While assembling the brake shoes and related hardware: A. The secondary shoe faces toward the front of the vehicle. B. The primary and secondary shoe return springs are interchangeable. C. The adjuster must be installed in the proper direction. D. The adjuster cable usually is mounted on the primary shoe.
The adjuster must be installed in the proper direction. (While assembling the brake shoes and related hardware, make sure the adjuster is installed in the correct direction. The other answer choices are wrong. The secondary shoe should face toward the rear of the vehicle, not the front. The primary and secondary shoe reutnr springs are not interchangeable. And, the adjuster cable is usually mounted on the secondary shoe, not the primary one.)
A metering valve delays pressure to which set of brakes under which braking condition? A. The rear brakes under light braking B. The rear brakes under heavy braking C. The front brakes under light braking D. The front brakes under heavy braking
The front brakes under light braking (A metering valve is used on systems with front disc and rear drum brakes. During brake application, the fluid pressure must overcome the force of the brake shoe return springs and force the shoes outward.)
When adjusting the parking brakes on a vehicle equipped with rear disc brakes: A. Do nothing because the parking brakes are self-adjusting. B. There should be 0.75 in (19 mm) of slack in the cables so they don't bind during application. C. The parking brake cable should be adjusted with the parking brake on one click so there will be a slight drag in the wheels. D. The parking brake cable should be adjusted so there is 0.50 in (1.27 mm) between the stopper pin and the stop.
The parking brake cable should be adjusted with the parking brake on one click so there will be a slight drag in the wheels. (When adjusting the parking brakes on a vehicle equipped with rear disc brakes, the parking brake cable should be adjusted with the parking break on one click so there is a slight dragi n the wheels.)
While servicing a wheel cylinder: A. The parts should be washed in a soap and water solution. B. If the cylinder is pitted or deeply scored, hone the wheel cylinder. C. The piston cups should be lubricated with cl ean brake fluid before installation. During assembly, the flat side of the pistons face the brake shoe links.
The piston cups should be lubricated with cl ean brake fluid before installation. (When serving a wheel cylinder, always lubricate the piston cups with clean brake fluid before installing them. Brake parts should be cleaned with denatured alcohol, not soap and water. If the cylinder bore is deeply pitted or scored, it should be replaced. Attempting to hone the defects away will result in an oversized bore, one in which the cups may not seal. During assembly, the flat side of the pistons should face the inside of the cylinder.)
A vehicle pulls to the left during a brake application. The cause of the problem could be: A.The right front brake linings are contaminated with grease. B. The piston is seized in the right front brake caliper. C. The master cylinder pistons are swollen from contaminated fluid. D. The secondary compensating port is plugged in the master cylinder.
The piston is seized in the right front brake caliper (The direction a vehicle pulls toward during the application of brakes is the side of the vehicle that has less braking power. If something on the right side were causing the brakes to drag or grab, the vehicle would tend to pull to the side with less braking power on the left side.)
While machining a brake drum: A. Tool chatter marks may be caused by excessive damping belt tension. B. The tool bit depth for a rough cut should be 0.005 to 0.010 in (0.127 to 0.254 mm). C. The tool bit depth for a rough cut should be 0.010 to 0.020 in (0.254 to 0.508 mm). D. The tool bit depth for a finish cut should be 0.008 to 0.010 in (0.203 to 0.127 mm).
The tool bit depth for a rough cut should be 0.005 to 0.010 in (0.127 to 0.254 mm). (While machining a brake drum a rough cut of 0.005 to 0.010 inches is recommended. The finish cut should be 0.005 inches or less.)
There is evidence of brake fluid leakage into the engine. The cause of the problem could be: A. a defective vacuum hose to the brake booster. B. a defective one-way check valve in the booster vacuum hose. C. a defective PCV valve with excessive restriction. D. a partially restricted air cleaner element.
a defective one-way check valve in the booster vacuum hose. (A is wrong because a defective hose would not allow brake fluid to enter the engine. C is wrong because the PCV valve vents the engine's crankcase of blowby gases and has nothing to do with the brake system. D is wrong because the air cleaner could in no way affect or cause a brake fluid leak.)
All of these conditions may cause illumination of the red brakew arning light EXCEPT: A. parking brake engagement B. low fluid level in the amster cylinder. C. an open wheel speed sensor winding. D. an accumulator pressure below 1,500 psi
an open wheel speed sensor winding. (An applied parking brake, low fluid level, or low accumulator pressure may cause the red brake warning lamp to turn on. The amber ABS lamp will come on when there is a fault in the ABS, such as a bad wheel sensor.)
Brake systems contain all of the following components EXCEPT: A. double wall copper tubing. B. high pressure rubber tubing. C. double wall steel tubing. D. flare nuts.
double wall copper tubing. (Copper tubing should never be used in brake systems. Copper corrodes easily and can expand due to high pressures.)
A vehicle has no brake pedal free play. This problem may cause: A. a low brake pedal. B. pressure build-up and dragging brakes. C. a spongy brake pedal. D. fluid leaking past the primary piston cups.
pressure build-up and dragging brakes.pressure build-up and dragging brakes. (Without some free play, the brakes may not fully unapply and may cause brake dragging.)
All of these defects may cause a car to pull to one side while braking EXCEPT: A. wrong or loose brake pads. B. loose caliper mounting bracket. C. seized master cylinder piston. D. sticking caliper pistons.
seized master cylinder piston. (All of the answers may cause a vehicle to pull to one side during braking, except answer C. A seized master cylinder piston would not affect side-to-side braking and would not cause pulling.)
On a vehicle with front disc and rear drum brakes, a scraping noise is present in one front wheel while braking. The cause of this problem could be: A. worn caliper pins and bushings. B. the pad wear sensor contacting the rotor. C. loose caliper mounting bolts. D. a loose pad mounting in the caliper.
the pad wear sensor contacting the rotor. (The scraping noise described in this question is known as an audible warning. The noise is designed to alert the driver of worn brake pads. Once the pads wear enough, a metal projection on the pad contacts the rotor and makes the noise when the brakes are applied.)
After a brake application, the caliper piston is returned by: A. the twisting action of the seal. B. a return spring. C. brake fluid pressure. D. atmospheric pressure.
the twisting action of the seal. (This is a theory based quesiton. The relaxing of the seal and the contact of the piston on the rotor causes the piston to recede after the brake pedal has been released.)
On a single piston floating caliper, the inside brake pad lining is worn out, but there is very little wear on the outside pad lining. The cause of the problem could be: A. worn caliper pins and bushings. B. a leaking caliper piston seal. C. a leaking brake hose. D. excessive rotor lateral runout.
worn caliper pins and bushings. (One pad wears more because the caliper is not free to move evenly as it tries to squeeze the pad onto the rotor.)