Correct answer: Excessive brake pedal travel
A short push rod length will have to travel farther for contact and result in excessive pedal travel.
Correct answer: Air in the hydraulic system
Air in the hydraulic system is the only choice that creates a spongy pedal.
Correct answer: Defective check valve
The defective check valve causes a loss in vacuum when the engine is off. That’s why the power assist begins to function properly after the engine runs. The other three answers wouldn’t cause the same issues.
Correct answer: An internal master cylinder leak
The cause of the brakes that moves slowly to the floor is an internal master cylinder leak.
Correct answer: Air in hydraulic system
Air causes a gap in the hydraulic fluid flow because the fluid has to compress the air before it can apply the piston. This delay causes the spongy feel. The other choices do not affect this concern.
Correct answer: Y only If the amber light is on it indicates an ABS fault and the system will revert to regular brake operation without ABS. Technician X is wrong because the parking brake only affects the RED Brake Light not the amber.
Correct answer: Weak hydraulic hose
The weak hydraulic brake hose causes a spongy pedal. The pressure can continue to build and the hose might expand, but not release the pressure to the brake units. Binding pedal linkage would lead to a hard pedal, which is also true for a dented brake line. The plugged compensator port leads to dragging brakes instead.
Correct answer: metering valve
The metering valve controls the pressure to the front disc brakes on a combination system and if defective can allow too much pressure causing a lock-up. The other choices will not do this.
Correct answer: Brake drum machined beyond its limit
The greatest drawback of drum brakes is that they are susceptible to fade. Brake fade is loss of stopping power that occurs when excessive heat reduces friction between brake shoe linings and drum. There are four types of brake fade. Mechanical fade occurs when the brake drum gets so hot it expands away from the brake linings. If the brake drum is machined beyond its limit the contact surface is further from the brake shoes and they move outward to maintain contact with the drum, causing the brake pedal to drop toward the floor as additional brake fluid moves into the hydraulic system. The other 3 choices would not cause brake fade.
Correct answer: Repair leak and replace brake linings
The leak must be repaired before the linings are replaced.
Correct answer: Pressure build-up and dragging brakes
When there’s no free play, the brakes can’t disengage fully. This leads to the brakes dragging. The other situations wouldn’t be caused by the lack of free play.
Correct answer: Y only
Insufficient clearance between the pads and caliper slider causes the slider not to move and only applies one brake pad causing only that pad to wear. Technician X is wrong because excessive rotor runout will cause brake pulsations with no effect on wear.
Correct answer: Metering valve
The metering valve controls the pressure to the front disc brakes on a combination system and if defective can allow too much pressure causing a lock-up. The other choices will not do this.
Correct answer: Drain the master cylinder
Draining the master cylinder isn’t required. If it needs to be done, the fluid can be removed after the lines are capped. Fluid will not run from the master cylinder while you remove it. Then, it’s easier to empty once it’s out.
Correct answer: Excessive rotor runout
Excessive rotor runout can be the cause of the vibration that comes from the front of a vehicle.
Correct answer: Brinelling
Brinelling is defined as indentations in the race caused by impact loads or vibrations.
Correct answer: Neither technician
Both of these techs are wrong. The brakes on quick take up systems use the exact bleeding procedure as systems without the valve. You don’t need to do anything different.
Correct answer: replace the rotor
If the front disc brake rotor is slightly below minimum thickness specification after machining, you have to replace the rotor.
Correct answer: Both X and Y
Both technicians are correct.
Correct answer: Excessive brake pedal travel
The short push rod length has to travel farther to make contact. This leads to excessive pedal travel. The other complaints wouldn’t occur as a result.
Correct answer: Replace the leaking line with double-flared steel tubing.
You have to replace the leaking line with double-flared steel tubing when the hydraulic brake line is leaking.
Correct answer: X only
You torque an adjusting nut to a specified torque and back off the nut till it lines up with the hole and install the cotter pin. Technician Y is wrong because backing off the castle nut will not cause the bearing to overheat.
Correct answer: High-pressure rubber tubing
Excessive tire pressure isn’t going to cause the erratic pulling. It will lead to increased tire wear. If the vehicle has low or uneven tire pressure, there might be a pull.
Correct answer: A failed master cylinder
A failed master cylinder could be the cause of a vehicle’s drum brakes increases after each application.
Correct answer: Both X and Y
Both technicians are correct.
Correct answer: Defective one-way check valve in booster vacuum hose
A defective hose would not allow the fluid to enter the engine. The PCV valve vents the crankcase of blowby gases and isn’t part of the braking system. The air cleaner also can’t cause a brake fluid leak.
Correct answer: Neither X nor Y
Both technicians are wrong because this is how power brakes are supposed to operate.
Correct answer: Neither X nor Y
Both technicians are wrong because the problem is in the power booster. Excessive freeplay delays application and air in the hydraulic system will cause a spongy pedal.
Correct answer: Double wall copper tubing
Copper tubing should never be used within the brake system. Copper corrodes easily which makes it a poor option. It also expands when subjected to high pressures.
Correct answer: Seized caliper piston
A seized caliper piston could cause the pedal to be high with reduced braking power.
