When tank pressure falls below 120 psi.

When tank pressure falls below 55 psi.

When tank pressure falls below 10 psi.

The brakes may not work.

The brakes may squeak more than usual.

The brakes will brake unevenly.

The air brakes should be used.

The vehicle should be placed in a low gear and the driver should use engine braking.

The driver should continually downshift instead of using the brakes.

One half

One quarter

One third

One tenth

Water and oil

Ammonia

Liquid cleaners

To reduce the risk of ice forming in air brake valves.

To make the compressor run more efficiently.

To lubricate parts of the braking system.

To reduce the risk of rust forming on air brake valves.

Look under the trailer for wheel speed sensors coming from the back of the brakes.

Look under the hood for the ABS sticker.

Look at the tires.

Remove a tire and look for the ABS sensor on the axle.

A check valve

A lock

A trap door

An oxidizer

The brake pedal should be pressed.

The brake pedal should be lifted.

The brake knob should be pulled out.

The brake knob should be pushed in.

Apply the brakes as hard as possible without locking the wheels.

Apply the brakes with about half-force.

Apply the brakes until the wheels lock.

Pump the brakes.

Not use the brake pedal.

Press the accelerator.

Move the steering wheel.

Only required when transporting gases.

Only required when transporting liquids.

Required when transporting both liquids and gases.

Optional when transporting hazardous materials.

Release air faster than it can be replaced.

Add more air to the braking system.

Make the brake pedal more sensitive.

Create a loud noise.

Apply the brakes completely until the wheels lock up, release the brakes until the wheels start rolling, then repeat the process.

Apply the brakes about halfway, but keep the wheels rolling.

Fully apply the brakes, let the wheels lock up, and hold the brake pedal down, keeping the wheels locked until the vehicle stops.

Apply the emergency brake.

The parking brake must be always be used.

The parking brake should never be used.

Windows in the cab should be lowered.

The compressor needs more air.

The air pressure has become too high.

The brakes are fully operational.

Be tested once a month.

Only be tested by a trained mechanic.

Be tested before every trip.

100 feet

250 feet

300 feet

450 feet

The brakes are very hot.

The brakes are very cold.

There is snow on the ground.

There is water on the ground.

2 psi

4 psi

6 psi

Not required on trucks.

Only required on trailers.

Required on tractors.

Only required when transporting hazardous materials.

Two inches

Five inches

One inch

To make the air brakes work more effectively.

To temporarily release the spring brakes.

To charge the brakes on the rear trailer.

The ABS is working properly.

The ABS has just been activated.

The ABS is not working properly.

The ABS needs to be activated.

Other brake systems squeak too loudly.

Air brakes are very effective systems.

Other braking systems are hard to come by.