Graded A+ solutions
Which of the following could cause the brakes on a truck to wear too fast?
A. glazed drums
B. wrong linings installed
C. Low air pressure
D. governor cut out pressure
B. wrong linings installed
which of the following could cause one brake on a truck to wear faster than the others?
A. mismatched service brake chambers
B. mismatched parking chambers
C. low air pressure in service tanks
D. governor cut out too low
A. mismatched service chambers
what force is used to apply the foundation brake wheel cylinders?
A. hydraulic from the steering reservoir
B. mechanical
C. electrical
D. hydraulic from the master cylinder
D.
there's an audible air leak from under the dash when the foot valve is applied. technician A says the
double check valve may be faulty. Tech B says the single check valve may be faulty. who's correct?
Tech A only
on a straight truck equipped with air brake, the secondary tank pressure gauge falls to zero when the
wet tank air is drained. Tech A says the one way check valve is faulty, Tech B says the foot valve may
be faulty. Who's correct?
Tech A only. one way check valve protects secondary tank
A loose wheel bearing adjustment can cause a faulty wheel speed sensor and a wheel speed sensor
code
Air dryer purges too often. Tech A says the air dryer delivery check Valve may be faulty. Tech B says a
leaking wet tank could be the cause. Who's correct?
C. Both Techs.
The safety valve releases on the air tank. Which is the most likely cause?
A. plugged line from the supply tank to governor.
B. faulty tractor protection valve
C. stuck spitter on the air drier
D. faulty secondary tank
A. if the line was plugged, the governor would not unload the compressor
, A truck with hydraulic disc/drum brakes has a high firm pedal with poor stopping. what could be the
cause?
The brake linings are glazed! Glazed brake linings will allow the pedal to feel high and firm with no
stopping power
Air builds on a truck in 1.5 minutes. The specs. manual says it should take 3.5 min. Tech A says the air
tanks could have water build up. Tech B says the air tanks could have oil built up. Whos correct?
C. Both technicians. Any Build up reduces volume for stored air
Brake fluid is leaking from the rear of a master cylinder on a hydro boost brake system. What is the
likely cause?
Primary seal leaking.
Air pressure build up time on a gear driven compressor is greater than specifications. What is the
cause?
A. a slipping drive
B. a leaking service relay
C. leaking primary tank
D. leaking parking brake chamber
C. A leaking primary air tank causes extended air build up time
air leaks from the left front modulator valve during service operation. There are no ABS codes. What
is the cause?
Modulator Valve seat
air is leaking from a quick release valve mounted on the front axle during service application. What is
the cause?
Quick release
The three ports on a governor are:
Reservoir, Unloaded and exhaust
Pressure valves open at :
150PSI
A new drum will not fit over the brake shoes. All the following could be the cause EXCEPT:
A. an incorrect drum
B. incorrect shoes
C. shoes are not properly adjusted
D. the parking brake is released
D. the parking brake is released
Air compressor has a broken connecting rod. the compressor crankshaft is not discolored. What is the
cause?
restricted air discharge line
all the brakes wear too quick on a truck. what is the cause?