Apply brakes with steady pressure at the beginning of a stop, then ease off as the vehicle slows. Just before the vehicle comes to a complete stop, release brakes to avoid jerk and rebound, then brake again to hold the vehicle while stopped.
Hydraulic brakes or air brakes should not be fanned (alternately applied and released) except on slippery pavement where this type of braking (called threshold braking) may give better control, reduce the danger of skidding and give a shorer stop. However, fanning air brakes may sharply reduce air pressure. Fanning serves no useful purpose on dry pavement and, on a long downhill grade, may reduce air pressure below the minimum pressure needed for stopping the vehicle.
Avoid excessive use of brakes on long downgrades as overheated brakes are dangerously inefficient. Gear down to use engine compression as the principal means of controlling speed on long grades. You should use the same gear going down a long grade as you would to climb it. Choose the lower gear before you begin going downhill.
If the low air pressure warning device operates at any time, stop immediately in the safest available place and have the problem corrected before you proceed.
If your brakes fail on a level road, down-shift (manual or automatic) and use engine compression to slow the vehicle. In an emergency, it may be necessary to use the emergency brake. Do not drive the vehicle again until repairs have been made.
Take care when braking on a wet or slippery surface or on a curve. Late or over-braking in these circumstances could cause skidding. To stop a skid, release the brakes, look and steer in the direction you want to go.
Retarders have become a popular option on motor coaches. They augment braking and help reduce service brake wear and brake fade, and are useful on long downhill grades.
There are three types of brake retarders: exhaust brakes, engine brakes, and driveline (transmission) retarders. Activation of the retarder is usually controlled by the driver by means of an "on-off” or variable set ting switch. In some buses, the retarder activates automatically when the service brakes are applied. Exhaust and engine brake retarders typically increase engine noise and many communities prohibit their use.
Always respect signs advising against the use of engine or exhaust brakes. Drive line retarders don’t increase engine noise. However, prolonged use increases transmission heat to the point that it could shut down the coach to protect the transmission from damage.
Warning: Because the retarder applies brake force only to the drive axle, activating the retarder while driving on a slippery surface can cause a loss of control and a collision. Do not use the retarder on wet, slippery or icy roads. During inclement weather, turn off the retarder using the maters (on-off) switch. Drivers who ignore this warning and experience a retarder-induced wheel lock-up or spin should immediately turn off the retarder to allow the drive wheels to roll freely and regain steering control.
Note: If you plan to operate a vehicle equipped with air brakes, refer to the Official Air Brake Handbook for more information.