When descending hills, you should always be in low range and have selected the gear required before descending. You should always avoid braking on downhill sections as you run the risk of locking up your wheels, causing a slide. Engine braking slows the vehicle without causing wheel lockup. However it is better to use the brakes than allow the vehicle to 'run away' and pick up speed. Always apply the brakes gently, rather than applying them abruptly and risking a wheel lockup.
Often hills get steeper the further you go down, so its best to be in 1st low from the beginning rather than having to try and change gear halfway down. When changing down a gear while descending, it is best to be feathering the brakes as you depress the clutch, as otherwise the vehicle freewheels while the clutch is depressed and picks up speed. It is far better to be in too low a gear and travel down slowly rather than be in too high a gear and have a potentially dangerous situation arise.
Hill Stall Recovery
A very common occurrence on hill climbs is the stalling of the vehicle when the hill becomes too steep. When this occurs, you will be left in gear with the engine switched on but stalled. To recover from this situation you should perform a Hill Stall Recovery, rather than just fire up the engine. This is accomplished by:
· Switch the (stalled) engine off and place your foot firmly on the brake.
· Depress the clutch and select reverse gear in low range.
· Take your foot off the clutch then slowly take your foot off the brake. The vehicle is now in reverse gear with the stalled engine stopping it from rolling down the hill.
· After checking the track behind is clear, start the engine and keep your feet off all pedals.
· The starter motor will start to drive the vehicle backwards as the engine begins to fire.
· This will result in a smooth downhill progression while starting the engine and ensuring you have been in gear at all times. If you simply start the engine and then select reverse gear, it will result in a fast jerky takeoff and being out of gear during some stage of the takeoff.
The Hill Stall Recovery does not apply to automatic vehicles as they should never stall, just lose forward drive when the hill becomes too steep for the gear its in. When this occurs, simply place your foot on the brake while restarting the engine, select the appropriate gear and gently take your foot off the brake.
A lesser used method after an uphill stall can be done in situations where the terrain is not extremely steep and you wish to continue forward up the hill but you do not wish to attempt to let the clutch out while trying due to tire spin. This method only applies to manual transmissions and drive trains that have very low forward gears. By leaving the vehicle in gear and starting the engine without pressing the clutch in the vehicle will begin to move forward while the engine fires. Once the engine fires you can begin forward movement. This method is hard on the starter and electrical system and should not be attempted on very steep terrain due to the possible overload on the electrical system and starter. Some vehicles will not allow the starter to be engaged if the vehicle's clutch is not depressed. In some cases this feature can be overridden by use of a clutch safety cancel switch.
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