T4 ASE Brakes
Study online at https://quizlet.com/_9pbg1s
1. Psi loss rate for 2 psi/minute
Straight Truck
2. Psi loss rate for less than 3 psi/minute
combination ve-
hicle
3. Service Brake Apply service brake to 90 psi. Loss rate should be less than 3 psi/minute for straight
Pressure Drop vehicles and less than 4 psi/minute for combination vehicles.
Test
4. Improperly ad- Cause
justed brake
shoes 1) brake imbalance
2) increased stopping distance
3) excessive heat and wear
5. Instability and a 4 psi difference in the air delivery between axles is enough to cause instability
premature wear and premature wear.
6. Troubleshooting 1) inspect air compressor
poor brake 2) verify pressure build up
performance 3) look for clogged air compressor filter
due to air 4) possible slipping belt
5) possible air leaks
6) possible defective governor
7. Pressure Gover- 1) regulates air going to system
nors 2) adjustable pressure
3) defective governor or out of adjustment can cause compressor to function
improperly.
4) designed to regulate the compressors output.
5) may be attached to compressor or externally mounted.
, T4 ASE Brakes
Study online at https://quizlet.com/_9pbg1s
8. Air Compressors 1) Power is transferred to the air compressor by either an internal gear or by an
external belt. Belt is most common.
2)air can be drawn directly from the atmosphere through a filter.
3) Pistons push the air through a discharge valve to the supply reservoir.
9. Supply Reservoir 1) tank closest to the compressor.
"Wet Tank" 2) "pop off valve" located on this tank to keep from over pressuring the system.
10. Pop-off valve Also known as the pressure relief valve, exhaust valve, adjustable pressure limiting
(APL) valve, or overflow valve; this valve is the point of exit of excessive pressure
buildup before damaging air components.
11. Manual and Au- 1) installed in each reservoir/tank to help purge the system from moisture.
tomatic Drain
Valves 2)Used in high humid or wet climates.
3) manual drain valves should be drained on a daily basis
12. Air Dryer 1) used to keep condensation out of the system using a desiccant material to
remove moisture.
2
13. Air Compressor 1) can develop air leaks and pass oil into the brake system which will cause poor
troubleshooting braking and or grabbing or dragging.
2) clogged air intake filter will cause slow pressure build up.
14. Compressor oil 1) engine oil should be checked for compressors that get lubrication from engine.
checks
2) Oil sump compressors have their own oil reservoirs and should be checked daily.
15.
Study online at https://quizlet.com/_9pbg1s
1. Psi loss rate for 2 psi/minute
Straight Truck
2. Psi loss rate for less than 3 psi/minute
combination ve-
hicle
3. Service Brake Apply service brake to 90 psi. Loss rate should be less than 3 psi/minute for straight
Pressure Drop vehicles and less than 4 psi/minute for combination vehicles.
Test
4. Improperly ad- Cause
justed brake
shoes 1) brake imbalance
2) increased stopping distance
3) excessive heat and wear
5. Instability and a 4 psi difference in the air delivery between axles is enough to cause instability
premature wear and premature wear.
6. Troubleshooting 1) inspect air compressor
poor brake 2) verify pressure build up
performance 3) look for clogged air compressor filter
due to air 4) possible slipping belt
5) possible air leaks
6) possible defective governor
7. Pressure Gover- 1) regulates air going to system
nors 2) adjustable pressure
3) defective governor or out of adjustment can cause compressor to function
improperly.
4) designed to regulate the compressors output.
5) may be attached to compressor or externally mounted.
, T4 ASE Brakes
Study online at https://quizlet.com/_9pbg1s
8. Air Compressors 1) Power is transferred to the air compressor by either an internal gear or by an
external belt. Belt is most common.
2)air can be drawn directly from the atmosphere through a filter.
3) Pistons push the air through a discharge valve to the supply reservoir.
9. Supply Reservoir 1) tank closest to the compressor.
"Wet Tank" 2) "pop off valve" located on this tank to keep from over pressuring the system.
10. Pop-off valve Also known as the pressure relief valve, exhaust valve, adjustable pressure limiting
(APL) valve, or overflow valve; this valve is the point of exit of excessive pressure
buildup before damaging air components.
11. Manual and Au- 1) installed in each reservoir/tank to help purge the system from moisture.
tomatic Drain
Valves 2)Used in high humid or wet climates.
3) manual drain valves should be drained on a daily basis
12. Air Dryer 1) used to keep condensation out of the system using a desiccant material to
remove moisture.
2
13. Air Compressor 1) can develop air leaks and pass oil into the brake system which will cause poor
troubleshooting braking and or grabbing or dragging.
2) clogged air intake filter will cause slow pressure build up.
14. Compressor oil 1) engine oil should be checked for compressors that get lubrication from engine.
checks
2) Oil sump compressors have their own oil reservoirs and should be checked daily.
15.
