Chapter 106

Two technicians are discussing ABS wheel speed sensors. Technician A says that some ABS use a sensor located in the rear-axle pinion gear area. Technician B says that all ABS use a wheel speed sensor at each wheel. Which technician is correct?

Tech A only

A customer wanted the ABS checked because of tire chirp noise during hard braking. Technician A says that the speed sensors may be defective. Technician B says that tire chirp is normal during an ABS stop on dry pavement. Which technician is correct?

Tech B only

Technician A says that ABS-equipped vehicles can stop quickly and without skidding on all road surfaces even if covered with ice. Technician B says that steering is possible during an ABS stop. Which technician is correct?

Tech B only

The faster a wheel rotates, the higher the frequency produced by a wheel speed sensor.

True

the modulator valve body is part of the master cylinder assembly in _________________ antilock systems

integral

wheel speed sensors consists of a _______________ and a toothed sensor ring also called a _____________.

magnetic pickup, tone ring

the accumulator on ABS systems has a pressure storage chamber filled with ____________

nitrogen gas

a ________________ consists of a wire coil with a movable core and a return spring

solenoid

integral systems do not have a __________________

vacuum booster

on dry or wet pavement the maximum braking traction occurs when tire slip is held between ________ and ________

15%, 30%

a fully charged accumulator in an integral ABS system can store up to ____________ of pressure for power assist braking

2,700 PSI

a tire slips how much during a ABS stop

20%

on snow or ice covered pavement the optimum slip range is __________

20% to 50%

at what speed does the antilock braking system stop controlling the wheel brakes?

5 MPH

Technician A says that ABS may not result in shorter stopping distances compared to brakes without ABS. Technician B says that a pulsating brake pedal during severe braking is a characteristic of most ABS-equipped vehicles. Which technician is correct?

Both

Technician A says that ABS brakes are designed to allow the front wheel to be steered during heavy braking. Technician B says that the ABS dash warning lamp is amber. Which technician is correct?

Both Technicians A and B

Technician A says that some wheel speed sensors are enclosed in a wheel bearing assembly. Technician B says that some wheel speed sensors are exposed to possible damage from road debris. Which technician is correct?

Both Technicians A and B

Technician A says that most ABS units are the integral type. Technician B says that the ABS is disabled (does not function) below about 5 mph (8 km/h). Which technician is correct?

Both technicians A and B

Which type of antilock braking system (ABS) requires the use of four wheel speed sensors?

Four channel

The maximum traction between a tire and the road occurs when the tire is _______________.

Slipping 10 to 20 percent

fluid is usually routed into a spring loaded or pressurized storage reservoir called an _______________

accumulator

nonintegral systems are also known as

add on systems and are the most popular because of their low cost and simplicity