Braking systems: bus & PCV theory test questions

1. To make the vehicle always stop in a shorter distance
2. To hold the vehicle still on a hill
3. To stop the wheels locking so you can keep steering while braking hard ✓
4. To slow the vehicle on long downhill stretches

Answer: To stop the wheels locking so you can keep steering while braking hard. ABS stops the wheels from locking under heavy braking, so you keep steering control. It doesn't always shorten your stopping distance.

The Highway Code: rule 120

1. Apply the footbrake firmly and keep the pressure on ✓
2. Pump the brake pedal on and off
3. Use only the parking brake
4. Brake lightly so the ABS doesn't operate

Answer: Apply the footbrake firmly and keep the pressure on. With ABS you should brake firmly and not release the pressure until you've slowed enough. The system stops the wheels locking.

The Highway Code: rule 120

1. Stop and have the fault checked before continuing ✓
2. Ignore it, as the normal brakes will still work
3. Drive faster to reset the system
4. Switch the engine off and on while moving

Answer: Stop and have the fault checked before continuing. A warning light that stays on means the ABS may not be working. Don't ignore warning lights; get the fault checked before you carry on.

The Highway Code: Annex 6

1. Stopping the vehicle in an emergency
2. Holding the vehicle when it's parked
3. Preventing wheel spin when moving off
4. Controlling speed on long downhill gradients without overusing the footbrake ✓

Answer: Controlling speed on long downhill gradients without overusing the footbrake. An endurance brake helps control your speed over long periods, such as on a long descent. This reduces wear and heat in the service brakes.

Vehicle handbook and operator guidance

1. It stops working completely in the wet
2. It will switch off the ABS
3. It could cause the drive wheels to lose grip and skid ✓
4. It makes the vehicle accelerate

Answer: It could cause the drive wheels to lose grip and skid. A retarder acts on the drive wheels, so on ice or a slippery surface it can make them lose grip. Check the handbook; you may need to switch it off.

The Highway Code: rule 231

1. Driving too slowly in a low gear
2. The brakes overheating from continuous use ✓
3. Using the endurance brake on a downhill slope
4. Tyres that are over-inflated

Answer: The brakes overheating from continuous use. Brake fade happens when the brakes get too hot from long or repeated use, such as on a long hill. They become much less effective.

The Highway Code: rule 122

1. Select a lower gear ✓
2. Select neutral to save fuel
3. Switch off the endurance brake
4. Speed up so you get down more quickly

Answer: Select a lower gear. Choosing a lower gear before a long downhill slope helps control your speed and reduces the work your brakes have to do.

The Highway Code: rule 160

1. Keep driving to your destination and report it there
2. Pump the brake pedal to raise the pressure
3. Switch off the engine at once while moving
4. Stop as soon as it's safe and don't continue until the fault is fixed ✓

Answer: Stop as soon as it's safe and don't continue until the fault is fixed. A low-pressure warning means your brakes could fail. Stop safely as soon as you can and get help before going further.

The Highway Code: Annex 6

1. Drive off slowly, as the pressure will build as you go
2. Release the parking brake to help the pressure build
3. Wait until the pressure builds up and the warning goes out ✓
4. Pump the footbrake until the warning goes out

Answer: Wait until the pressure builds up and the warning goes out. You must not move off until there's enough air pressure for the brakes to work. Wait for the gauges to show enough pressure and for the warning to stop.

The Highway Code: Annex 6

1. To reduce the vehicle's weight
2. To remove water that collects in the system ✓
3. To release pressure before a long journey
4. To cool the brakes after use

Answer: To remove water that collects in the system. Moisture can collect in air tanks. It can corrode parts or freeze in cold weather and affect the brakes, so it needs to be removed.

Vehicle handbook and operator guidance

1. An exhaust brake ✓
2. An electromagnetic retarder ✓
3. An anti-lock braking system
4. A spring parking brake

Answer: An exhaust brake; An electromagnetic retarder. Exhaust brakes and electromagnetic retarders are endurance brakes that help control speed without using the service brakes. ABS and the parking brake do different jobs.

Vehicle handbook and operator guidance

1. Low windscreen washer fluid
2. A faulty speed limiter
3. Too little fuel in the tank
4. A brake fault or incorrectly inflated tyres ✓

Answer: A brake fault or incorrectly inflated tyres. Pulling to one side when braking usually means a brake fault or wrong tyre pressures. Have it checked straight away.

The Highway Code: Annex 6

1. So the tachograph records the stop
2. So you can keep the engine at high revs
3. So standing passengers aren't thrown off balance ✓
4. So the doors open automatically

Answer: So standing passengers aren't thrown off balance. Harsh or late braking can throw passengers around and cause injuries, especially to those standing. Planning ahead lets you brake gently.

The Highway Code: rule 117

1. Braking as hard as possible as late as possible
2. Braking lightly at first, then more firmly, then easing off just before you stop ✓
3. Using only the endurance brake to stop
4. Pumping the brake pedal several times

Answer: Braking lightly at first, then more firmly, then easing off just before you stop. Progressive braking means braking early and lightly, increasing the pressure, then easing off just before stopping. It gives a smooth stop for passengers.

The Highway Code: rule 117

1. Apply the parking brake ✓
2. Keep your foot lightly on the accelerator
3. Leave the bus in gear with the clutch pressed
4. Switch on the endurance brake only

Answer: Apply the parking brake. Applying the parking brake makes sure the bus can't move while people are getting on or off. A small movement could cause someone to fall.

The Highway Code: rule 239

1. Passengers make the brakes colder
2. The ABS switches off when the coach is full
3. Full coaches have lower speed limits
4. The extra weight needs more braking force to stop ✓

Answer: The extra weight needs more braking force to stop. A heavier vehicle carries more momentum, so it needs more braking force and distance to stop. Leave a bigger gap when you're fully loaded.

The Highway Code: rule 126