Exam 29: Hydraulic Brakes and Air-Over-Hydraulic Brake Systems

You are measuring the axial TIR of a hydraulic brake rotor and through one revolution you measure +0.003-inch and -0.006-inch.What is the TIR?

What is the primary cause of disc brake rotor warpage?

Technician A says that excessive rotor runout on hydraulic brake systems can result in brake pedal pulsation.Technician B says that excessive rotor runout can cause decreased pedal travel.Who is correct?

Technician A says that a dual circuit hydraulic brake system master cylinder can be known as a tandem master cylinder.Technician B says that a tandem master cylinder has a single bore and two separate pistons.Who is correct?

Which of the following features of a hydraulic brake system are mandatory by FMVSS 105 compliant vehicle?

What should be done before forcing a caliper piston back into its bore while servicing hydraulic disc brakes?

What could the source(s)of hydraulic fluid pressure that operates typical brake boosters?

When the driver depresses the brake pedal of the typical truck with air-over-hydraulic brakes,which of the following occurs?

Technician A says that DOT 4 hydraulic brake fluid can be destroyed in as little as one hour exposure to atmospheric air.Technician B says that DOT 5 hydraulic brake fluid is hygroscopic.Who is correct?

Which of the following are functions of a typical hydraulic brake system combination valve?

Which of the following statements about a typical hydraulic brake system are true?

Technician A says that ABS hydraulic brake systems should be bled using a bleeder ball.Technician B says that a bleeder ball regulates output air pressure at approximately 15 psi.Who is correct?

Which of the following statements regarding the function of a tandem master cylinder during normal operation is true?

Which of the following guidelines is best practice for reusing brake fluid drained during bleeding operations?

Which of the following methods would be preferred when bleeding a typical air-over-hydraulic brake system?

What is the primary function of a pressure differential valve used in a hydraulic brake circuit?

Technician A says that drum servo brakes are self-energizing.Technician B says that servo brakes both primary and secondary shoes play a role in braking the drum whether the vehicle is moving forward or in reverse.Who is correct?

When honing a cast iron master cylinder,what should be used to lubricate the hone?

Which of the following valves delays application force to front disc brakes to balance a typical disc/drum hydraulic brake system?

Technician A says that contaminants tend to collect in the caliper bore of a hydraulic disc brake system so the piston should never be forced back into its bore without cracking the bleed screw.Technician B says that ABS hydraulic brake systems are more vulnerable to problems caused by contaminants in brake fluid.Who is correct?