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WorksheetsDSL-204 Chap 38 Hydraulic and Air-Over-Hydraulic Fundamentals
Total questions: 20
Worksheet time: 10mins
Technician A says that a more significant advantage for hydraulic brakes over air brakes is the use of highly pressurized brake fluid to apply disc foundation brakes. Technician B says that a more significant advantage for hydraulic brakes over air brakes is the use of low pressurized brake fluid to apply disc foundation brakes. Who is correct?
Technician A
Technician B
Both Technician A and Technician B
Neither Technician A nor Technician B
__________ data input from other control system modules to the full power hydraulic brake system control unit can add new features and enhance braking effectiveness.
CAN
WAN
LAN
Inter-network
A(n) ________ by Navistar is used by Class 4-7 vehicles, including Freightliner models.
Full power brake system
Hydraulically assisted braking system
Surge braking system
Electric trailer brake system
When discussing brake-by-wire technologies, Technician A says that the fixed piston-type caliper uses either an electric actuator or hydraulic fluid to apply and release the parking brake cable. Technician B says that the fixed piston-type caliper uses high-speed actuators to apply and release the parking brake cable. Who is correct?
Technician A
Technician B
Both Technician A and Technician B
Neither Technician A nor Technician B
Which of these hold true about master cylinder operation?
Brake fluid creates a solid hydraulic link that causes backward movement of the secondary piston.
The master cylinder pistons have seals at each end called cups.
Brake fluid for the brake application is supplied to the cavities surrounding the master cylinder pistons by the front calipers.
A second set of ports called the equalization ports allow brake fluid in front of the pistons.
When discussing conventional hydraulic braking systems; Technician A says that pushing the primary piston forward pressurizes brake fluid between both cups of the primary piston. Technician B says that pushing the secondary piston forward pressurizes brake fluid between both cups of the primary piston. Who is correct?
Technician A
Technician B
Both Technician A and Technician B
Neither Technician A nor Technician B
Which of these best describes hydrophilic?
The fluid does not absorb moisture.
The ability of the fluid to absorb water
The ability of the fluid to absorb moisture
The ability of the fluid to absorb air
A typical flex line construction uses a Teflon inner seal layer protected by __________ and reinforced with braided steel mesh to resist swelling during brake applications.
Kevlar
Nylon
Dyneema
Spectra
Brake ________ are used to pull the brake shoes back to resting position away from the brake drums when the brakes are released.
Springs
Hoses
Calipers
Pads
Technician A says that the inlet line and outlet line from the metering valve should be disconnected while testing the metering valves. Technician B says the outlet line from the metering valve should be disconnected while testing the metering valves. Who is correct?
Technician A
Technician B
Both Technician A and Technician B
Neither Technician A nor Technician B
Brake caliper pistons are made from aluminum; chrome-plated steel; and high-temperature-resistant, plastic-like materials called ________.
Phenolics
Flavonoids
Tannins
Coumarins
Which of these holds true for fixed calipers?
They slide back and forth across the rotor.
They are bolted to the torque plate and do not move.
This design is the root cause of the problems associated with wear and sticking of slider pins.
Parting halves of the fixed rotor are assembled with serviceable bridge bolts.
Technician A says air over hydraulic brake systems are divided into two categories. Technician B says split hydraulic brake systems require two separate air cylinders acting on a master cylinder. Who is correct?
Technician A
Technician B
Both Technician A and Technician B
Neither Technician A nor Technician B
In which of these modes are brakes released during regular brake operation?
Isolation mode
Dump mode
Reapply mode
Normal brake mode
In which of these modes are brakes released after the wheel has locked up?
Isolation mode
Dump mode
Reapply mode
Normal brake mode
To provide differential braking, the HPB system traction control switch in the dash should be in the "enable" position and wheel speed must be below __________.
21 mph
31 mph
41 mph
21 mph
Technician A says that if equipped and programmed for ATC, the HCU has an ATC modulator valve consisting of another inlet valve and outlet valve. Technician B says that if equipped and programmed for ATC, the HCU has a frequency modulator valve consisting of another inlet valve and outlet valve. Who is correct?
Technician A
Technician B
Both Technician A and Technician B
Neither Technician A nor Technician B
FMVSS requires that a park brake must hold a vehicle stationary on as much as a __________ grade in the forward and reverse direction for a test limit of 5 minutes.
30%
20%
50%
60%
Driveline park brake shoes have both __________ brake action.
Service and emergency
Single acting and dual acting
Primary and secondary
Self-energizing and servo
__________ is one of the causes for spongy brake pedal.
Oversized worn drums
Defective master cylinder seals
Glazed brake friction materials
Cracked rotor
