T4 Brakes ASE (B) fully
solved & updated
2025-2026(latest
version verified for
accuracy)
a driver complains that the compressor on his truck cuts in after every
brake application. Tech A says the compressor drive may be worn, creating
a lag time. Tech B says the air reservoirs may be loaded up with moisture.
Who's right? - answer Tech B
The secondary tank pressure gauge falls to zero when the primary tank is
drained on a straight truck equipped with an air brake. Tech A says the
double check valve may be faulty. Tech B says the single check valve may
be faulty. Who's right? - answer Tech A
There's a clunk noise when the brakes are applied on a truck equipped
with four wheel disc brakes. Tech A says the cause could be work caliper
slides. Tech B says the cause could be a loose caliper. Who's right? -
answer Both
An automatic slack adjuster won't keep the brake in adjustment. Tech A
says the problem may be an incorrectly installed slack adjuster. Tech B
says the problem may be that mismatched brake chambers are installed
on the axle. Who's right? - answer Tech A
An air governor test is being performed. Tech A says cut out should occur
at 20-25 psi below governor cut in. Tech B says to set governor cut in
before checking cut out. Who's right? - answer Neither
,Tech A says caliper slide pins should be prelubed with wheel bearing
grease. Tech B says caliper slide pins should be installed with an impact
wrench. Who's right? - answer Neither
The low air pressure warning in the cab is activated, but the air brake
system is operating normally. Which of the following is the LEAST LIKELY
cause?
A) the low air pressure sensor is shorted
B) the wire to the low air pressure sensor is grounded
C) the wrong air pressure switch was installed
D) the air compressor is faulty - answer D
The parking brakes on a truck equipped with air brakes are slow to apply.
Which of the following is the MOST LIKELY cause?
A) ruptured hold off diaphragm
B) plugged exhaust port
C) leaky brake chamber
D) failed mounting bracket - answer C
On a truck with single piston sliding caliper disc brakes, which of the
following is the LEAST LIKELY to require disc brake replacement?
A) a seized disc brake caliper
B) a seized disc brake caliper piston
C) glazed brake pads
D) oil contaminated brake pads - answer B
The measurement from the brake chamber to the middle of the clevis pin
is adjusted by:
A) Turning the clevis
B) Turning the brake adjustment screw
C) Loosening and rotating the brake chamber
, D) Turning the slack adjuster screw - answer A
A truck with air disc brakes has dragging brakes. Tech A says the relay
valve may be sticking. Tech B says the air drier heater may be stuck on.
Who's right? - answer A
A truck is equipped with an electronic stability control system. The brake
pressure sensor will be located in the:
A) primary tank
B) secondary tank
C) primary supply circuit of the treadle valve
D) the delivery port of the parking brake control valve - answer D
Two techs are discussing the automatic traction control system. Tech A
says that the ATC only functions on the drive axles. Tech B says if wheel
spin is detected, the ECU may limit the engine. Who's right? - answer C
When installing a new wheel seal, Tech A says that some seal
manufacturers recommend applying a thin coat of sealant to the hub seal
before installing the seal. Tech B says that if a seal wear ring is used a thin
coat of sealant should be applied to the shoulder of the wheel spindle
before installing the wear ring. Who's right? - answer Both
Any of these can cause longer than normal air pressure build up time
EXCEPT:
A) leaking primary air tank
B) a restricted secondary air tank
C) a restricted air inlet
D) a leaking line between the compressor and the air drier - answer B
A truck equipped with a hydraulic brake booster has a low pedal. What's
the MOST LIKELY cause?
A) low power steering fluid
B) leaky wheel cylinder
solved & updated
2025-2026(latest
version verified for
accuracy)
a driver complains that the compressor on his truck cuts in after every
brake application. Tech A says the compressor drive may be worn, creating
a lag time. Tech B says the air reservoirs may be loaded up with moisture.
Who's right? - answer Tech B
The secondary tank pressure gauge falls to zero when the primary tank is
drained on a straight truck equipped with an air brake. Tech A says the
double check valve may be faulty. Tech B says the single check valve may
be faulty. Who's right? - answer Tech A
There's a clunk noise when the brakes are applied on a truck equipped
with four wheel disc brakes. Tech A says the cause could be work caliper
slides. Tech B says the cause could be a loose caliper. Who's right? -
answer Both
An automatic slack adjuster won't keep the brake in adjustment. Tech A
says the problem may be an incorrectly installed slack adjuster. Tech B
says the problem may be that mismatched brake chambers are installed
on the axle. Who's right? - answer Tech A
An air governor test is being performed. Tech A says cut out should occur
at 20-25 psi below governor cut in. Tech B says to set governor cut in
before checking cut out. Who's right? - answer Neither
,Tech A says caliper slide pins should be prelubed with wheel bearing
grease. Tech B says caliper slide pins should be installed with an impact
wrench. Who's right? - answer Neither
The low air pressure warning in the cab is activated, but the air brake
system is operating normally. Which of the following is the LEAST LIKELY
cause?
A) the low air pressure sensor is shorted
B) the wire to the low air pressure sensor is grounded
C) the wrong air pressure switch was installed
D) the air compressor is faulty - answer D
The parking brakes on a truck equipped with air brakes are slow to apply.
Which of the following is the MOST LIKELY cause?
A) ruptured hold off diaphragm
B) plugged exhaust port
C) leaky brake chamber
D) failed mounting bracket - answer C
On a truck with single piston sliding caliper disc brakes, which of the
following is the LEAST LIKELY to require disc brake replacement?
A) a seized disc brake caliper
B) a seized disc brake caliper piston
C) glazed brake pads
D) oil contaminated brake pads - answer B
The measurement from the brake chamber to the middle of the clevis pin
is adjusted by:
A) Turning the clevis
B) Turning the brake adjustment screw
C) Loosening and rotating the brake chamber
, D) Turning the slack adjuster screw - answer A
A truck with air disc brakes has dragging brakes. Tech A says the relay
valve may be sticking. Tech B says the air drier heater may be stuck on.
Who's right? - answer A
A truck is equipped with an electronic stability control system. The brake
pressure sensor will be located in the:
A) primary tank
B) secondary tank
C) primary supply circuit of the treadle valve
D) the delivery port of the parking brake control valve - answer D
Two techs are discussing the automatic traction control system. Tech A
says that the ATC only functions on the drive axles. Tech B says if wheel
spin is detected, the ECU may limit the engine. Who's right? - answer C
When installing a new wheel seal, Tech A says that some seal
manufacturers recommend applying a thin coat of sealant to the hub seal
before installing the seal. Tech B says that if a seal wear ring is used a thin
coat of sealant should be applied to the shoulder of the wheel spindle
before installing the wear ring. Who's right? - answer Both
Any of these can cause longer than normal air pressure build up time
EXCEPT:
A) leaking primary air tank
B) a restricted secondary air tank
C) a restricted air inlet
D) a leaking line between the compressor and the air drier - answer B
A truck equipped with a hydraulic brake booster has a low pedal. What's
the MOST LIKELY cause?
A) low power steering fluid
B) leaky wheel cylinder
