Gabriel's Air Brake Test

Setting up the bus (the before)

I need to/make sure the…

• chock/block vehicle

• seatbelt

• engine is running

• spring brake is applied

• transmission is in neutral

• air pressure is at _______ psi which is above 90 psi.

LOW AIR WARNING DEVICE

FAN the brakes until Low air warning LIGHT and BUZZER turn ON.

Q: The Low Air Warning Device activated at _____ psi. This test is a Pass/Fail because it activated at _____ psi.

A: At or above 55 psi.

AIR PRESSURE BUILD-UP

Turn on LOW IDLE at 600-900 RPMS.

FAN the brakes to bring air pressure below 80 psi. Wait until pressure reaches 85 psi and start timing to see how long it takes to reach 100 psi.

Q: My air pressure is now at 85 psi, and I will start timing until it reaches 100 psi. Air pressure is at 100 psi and it took _____ seconds/minutes.

A: 2 minutes or less. This test is a pass because it took 2 minutes or less; it would have failed if it took longer.

GOVERNOR CUT-OUT

I’m watching the air pressure needles until they stop at the maximum point.

Q: Air pressure CUT OUT is at _____ psi.

A: Between 100 and 145 psi. The test is a pass because the governor cut out between 100 and 145 psi; it would have failed if it was below 100 psi or above 145 psi.

GOVERNOR CUT-IN

I’m going to lower the air pressure by 20-25 psi below the cut out point to ____ psi (solid #)

WATCH if the needle starts moving up. If not, keep lowering the air pressure in increments of 5 psi until the needles start moving.

Q: Air pressure CUT-IN at ______ psi.

A: At or above 80 psi. The test is a pass because the governor cut in at or above 80 psi; it would have failed if it was below 80 psi.

The NOR for this vehicle is between ____ & _____ psi. (I think it’s between 80 and 100 psi, or 20-25 below the cut-out pressure).

AIR LOSS RATE

My air pressure is currently at _____ psi which is within the NOR.

• Foot on service brake

• Release spring brake

• Turn engine off

• Wait for needles to stabilize

Air pressure is currently at _____ psi and I am going to start timing now for 1 minute.

• Time for 1 minute and check for air loss. At the end of the minute, apply the spring brake while keeping your foot on the service brake.

Q: 1 minute is up (apply spring brake) and the air pressure is at ____ psi for a loss of _____ psi.

A: less than 3 psi. The test is a pass because the bus lost 3 psi or less; it would have failed if it lost more than 3 psi.

SPRING BRAKE

• Remove chocks/blocks from vehicle

• Seatbelt

The air pressure is currently ______ psi which is within the NOR.

• Foot on service brake

• Place transmission in DRIVE

• Scan mirrors, blind spots, and honk the horn

• Attempt to move bus forward with1/3 throttle

• Secure the bus

A: Bus did not move. The test is a pass because the bus did not move; it would have failed if the bus moved.

SERVICE BRAKE

My air pressure is currently _____ psi which is within the NOR.

• Foot on service brake

• Release spring brake

• Place transmission in DRIVE

• Scan mirrors, blind spots, and honk the horn

• Move the bus a few feet, apply service brakes

• Secure bus.

A: Bus stopped smoothly without any pull to the left or right. The test is a pass because the bus stopped smoothly and did not pull to the left or right; it would have failed if it pulled or didn’t stop smoothly.

INTERLOCK (REAR DOOR)

My air pressure is currently _____ psi which is within the NOR.

• Foot on service brake

• Release the spring brake

• Place transmission in DRIVE

• Open rear door (Exit Doors)

• Scan mirrors, blind spots, and honk the horn

• Attempt to move the bus forward

• Secure the bus

A: bus did not move, engine did not rev. The test is a pass because the bus did not move and the engine did not rev; it would have failed if the bus moved or the engine revved.

Closing Statement

This bus passed all seven air brake tests and is safe to operate in service.

If it has failed any one of the brake tests the vehicle would be OUT OF SERVICE and I would report the defects.

M.A.P.S TEST (Measuring Applied Pushrod Stroke) 🌞

• Hi my name is Gabriel ❤

• Check/block vehicle

• Confirm engine is ON

• Spring brake is applied

• Transmission is in NEUTRAL

• PSI is over 90 psi and is currently at _____ psi

• Release spring brake and turn engine off

• Ensure psi is between 90 and 100 and is currently at _____ psi

• Exit vehicle and identify brake chamber type as CLAMP STYLE BRAKE CHAMBER

• Mark the pushrod (ALL) where it meets the brake chamber

• Confirm PSI is still between ___ and ___psi and is currently at ___ psi

• Ask an assistant to make and hold a full service brake application

• Measure from the brake chamber to the extended mark on the pushrod

• Ask assistant to SECURE THE BUS

• Record your mark in the provided chart

A: equal or less than ADJUSTMENT LIMIT. This test will pass if the measurement is equal to or less than the ADJUSTMENT LIMIT. It will fail if it is greater than the adjustment limit, and the vehicle would be placed in NOT IN SERVICE and the defects would be REPORTED.

SUPPLEMENTALS DRAINING AIR TANKS TEST 🌙

• Chock/block vehicle

• confirm engine is ON

• spring brake is applied

• transmission is in Neutral

• PSI is in NOR ___ and currently at ___ psi.

• Turn engine OFF

• Confirm psi is still in NOR ___ and currently at ___ psi.

A: make sure the tanks are:

• securely mounted

• drain valve is working

• the discharge is clear when fully drained.

CIRCLE CHECK - EXTERIOR

• enter bus

• move door control handle to FULL FORWARD

• turn master controller to NIGHT RUN

• start bus

• turn ON high beams and hazard lights

• exit bus - check the high beams

• turn OFF high beams

• exit bus

refer to images for full inspection

Front of Bus Inspection

Left Side of Bus

Rear of Bus

Right Side of Bus