T4 Brakes ASE | T4 ASE Brakes Medium/Heavy Duty
Brakes| Ques ons and answers | Updated RATED A+ |
NEW 2026
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 founda!on 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 o'en. 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 protec!on valve
C. stuck spi)er 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 !me on a gear driven compressor is greater than specifica!ons. 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 !me
, air leaks from the le' front modulator valve during service opera!on. 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 applica!on.
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 connec!ng rod. the compressor cranksha' is not discolored. What
is the cause?
restricted air discharge line
all the brakes wear too quick on a truck. what is the cause?
s!cking foot valve - causes brake drag
Tech A says brake fluid should be changed every 12 months or 12000 miles. Tech B says brake
fluid should be purchased in small containers. Whos correct?
Tech B. Brake fluid should be bought in small containers and used to prevent moisture built up
What can cause oil build up in the air tanks?
A restricted discharge line - will cause increased compressor heat and can result in compressor
oil passing
Front brakes on a truck pull when stopping. What can be the cause?
Mismatched brake linings
Brakes| Ques ons and answers | Updated RATED A+ |
NEW 2026
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 founda!on 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 o'en. 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 protec!on valve
C. stuck spi)er 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 !me on a gear driven compressor is greater than specifica!ons. 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 !me
, air leaks from the le' front modulator valve during service opera!on. 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 applica!on.
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 connec!ng rod. the compressor cranksha' is not discolored. What
is the cause?
restricted air discharge line
all the brakes wear too quick on a truck. what is the cause?
s!cking foot valve - causes brake drag
Tech A says brake fluid should be changed every 12 months or 12000 miles. Tech B says brake
fluid should be purchased in small containers. Whos correct?
Tech B. Brake fluid should be bought in small containers and used to prevent moisture built up
What can cause oil build up in the air tanks?
A restricted discharge line - will cause increased compressor heat and can result in compressor
oil passing
Front brakes on a truck pull when stopping. What can be the cause?
Mismatched brake linings
