WorksheetsDSL-204 Chap 35 Servicing Air Brake Air Systems
Total questions: 20
Worksheet time: 10mins
All of the following are good safety practices to follow during brake system service, EXCEPT:
Keep hands away from brake chambers and related parts.
Do not remove a component or pipe plug until all system air pressure has been depleted.
Use compressed air or dry brushing to clean brake parts or assemblies.
Wear a disposable face mask.
Which of the following is a step that technicians must follow to prepare the vehicle correctly for brake service activity?
Support the vehicle using a jack.
Make sure all battery cables are connected.
Enable the ATC function on vehicles with automatic traction control.
Block the wheels with purpose-made wheel chocks.
Technician A says all brake steer issues are caused by the braking system. Technician B says brake pull, also called brake steer, is an unintended left or right direction change by a vehicle during a brake application. Who is correct?
Technician A only
Technician B only
Both Technician A and Technician B
Neither Technician A nor Technician B
All of the following statements are correct about braking odors, EXCEPT:
Complaints about smell generally indicate rapid brake wear.
Smells are typically related to overheated brake lining.
Having grease on the friction material when the linings overheat can produce complaints.
Odors are often an indication of a lack of lubrication of the camshafts.
Braking odors are typically related to overheated __________.
Brake chambers
Brake drums
Bushings
Brake linings
Which of the following defects in the foundation brakes can result in sluggish brake application or release?
Excessive tank (reservoir) pressure
One-way check valve
Damaged, kinked, pinched, or undersized brake hoses and/or lines
Automatic drain valve
An inoperative low air warning light can be caused by all of the following, EXCEPT:
Air leakage
Defective circuit ground
Defective switch
Low crankcase pressure
All of the following are the most likely indicators of a problem with the park control valve, EXCEPT:
Leaks at exhaust port
Parking brakes won't release
Sluggish park application
Parking brakes won't apply
Worn __________ for range control cylinders can leak internally inside a transmission and can be hard to pinpoint.
Governor air lines
O-rings
Gladhand seals
Air dryer purge valves
What can be used to pinpoint leaks in the air brake system?
Carpenter's square
Application of air pressure
Soapy water
Cardboard square placed over the compressor's air outlet
Which of the following is responsible for removing oil passed into the air supply by the compressor?
Exhaust port
Service chamber
Air dryer
Air reservoir
To test the functioning of the automatic emergency brake system, what test would be performed?
Chuff test
Road test
Dual circuit integrity test
Gladhand test
Technician A says the operation of ABS modulator valves can be checked during the initial cycle of the ignition switch. Technician B says the modulator valves can be checked with an voltmeter for proper resistance rather than relying on a sound-based chuff test. Who is correct?
Technician A only
Technician B only
Both Technician A and Technician B
Neither Technician A nor Technician B
The first step of a dual-circuit integrity test involves draining the front axle reservoir to 0 psi and then verifying which of the following?
The trailer park brakes should apply only after the tractor protection valve closes.
The front axle brakes should apply and release.
The rear axle reservoir does not lose any pressure.
The trailer park brakes should apply and release.
__________ is created by having equal air pressure at all wheel ends at the same time.
Pneumatic imbalance
Pneumatic balance
Torque imbalance
Torque balance
All of the following are common causes of torque imbalance, EXCEPT:
Grease-contaminated friction material
Uniform friction material
Oversized drums and thin rotors
Mismatched brake chambers and automatic slack adjusters
Unbalanced brake pressures can be caused by __________.
Glazed friction material
Malfunctioning relay valves
Polished drums or rotors
Improperly installed automatic slacks
Technician A says it is helpful to remember when diagnosing a problem with a specific brake circuit that nylon air line tubing is color coded to designate to which air circuit it belongs. Technician B says nylon air lines must never be routed in areas where temperature could exceed 170°F (77°C). Who is correct?
Technician A only
Technician B only
Both Technician A and Technician B
Neither Technician A nor Technician B
Which of the following is identified by the sudden exhaust of air draining from the dryer?
Purging
Unloading
Snubbing
Burnishing
A gauge will require replacement if there is a difference of __________ compared with measurements made with an accurate master gauge
3 psi to 4 psi (20 kPa to 27 kPa)
4 psi to 5psi (27 kPa to 34 kPa)
2 psi to 3 psi (14 kPa to 20 kPa)
1 psi to 2 psi (7 kPa to 14 kPa)
