Hill-holder

Any device that prevents a car from rolling backward on a hill when the brake pedal is released can be called a hill holder. The earliest hill holders were used in horse-drawn carriages and early horseless carriages. They were often home-made or made by a local blacksmith. These early hill holders were little more than a heavy iron weight with a spike or other sharp end that could be quickly dropped behind a wheel when the need arose, preventing the vehicle from rolling backward.

Hill-Holder is a name for the mechanism invented by Wagner Electric and manufactured by Bendix Brake Company in South Bend, Indiana. Studebaker[1] and many other carmakers offered the device as either optional or standard equipment for many years. It is a device that holds the brake until the clutch is at the friction point, making it easier to start up hills from a stop in manual transmission automobiles. It was first introduced in 1936 as an option for the Studebaker President. By 1937 the device, called "NoRoL" by Bendix, was available on Hudson, Nash and many other cars. Another name for the mechanism is a hill hold control (HHC).

Availability

As a trade name, it was introduced by Studebaker in the 1936 President. It was also promoted by Studebaker as an option in the 1939 model year. Later, it was available on older Subarus, and is currently available on the Subaru Forester,[2] Subaru Impreza and Subaru Legacy The 2009 Dodge Challenger SRT8[3] also comes equipped with hill-holder. Hill-holder works by holding the brake in position while the driver sets-up and activates the first gear to move the car forward from a complete stop, without fear of roll-back.

Similar systems are or were in use by Alfa Romeo, Citroën, Fiat (including the new Fiat 500), BMW, Skoda Superb 2009, Lancia, Mercedes-Benz, Volkswagen, Lamborghini Aventador, Saab, smart ("Hill Start Assist"), Subaru, Cadillac ("NoRol") and Stutz ("Noback").

The mechanism was available in American car parts stores so that car owners could add to their vehicle to improve it from the late 1930s through the 1950s. But it required that the car have hydraulic brakes, so it could not be added to Ford Motor Company products before 1939. In 1949 it became available on factory-built Fords. GM would not follow suit until the 2012 Chevrolet Sonic.

Cars with Hill-holder feature:

Make Model Year Comment Reference
Subaru Outback 2003-Current?? above
Subaru Impreza 2003 above
Subaru Legacy 1989-Current? above
Dodge Challenger SRT8 2009 [4]
Fiat 500 Sport 2011 [5]
Chevrolet Sonic 2012 [6][7]
Honda CR-Z 2012 Called "Hill Start Assist" [8]
Honda Fit and Fit Hybrid 2015 (NOT 2013) [9]
Chevrolet Spark 2013 Called "Hill Start Assist" [10]
Mercedes-Benz Smart ForTwo 2011 Called "Hill Start Assist" [11]
Mercedes-Benz GL320 2008 [12]
Mercedes-Benz M-Class 2012 [13]
Volkswagen Passat 2012 [14]
Audi A3 2012 [15]
Kia Soul 2012 [16]
BMW 5-Series 2012 [17]
Mahindra E2O 2013 electric car [18]

Operation

In layman’s terms, the modern hill-holder function works by using two sensors, in concert with the brake system on the vehicle. The first sensor measures the forward-facing incline (nose higher than tail) of the vehicle, while the second is a disengaging mechanism. The 1930s-1950s NoRoL used a ball bearing as a check valve in the hydraulic brake line; when the car was on an uphill incline, the ball rolled back and blocked the brake line - when the car was level or facing downhill, the ball rolled away, leaving the line free. The clutch linkage slightly dislodged the ball when the clutch was released, enabling the car to move away from a stop.

Manual transmission vehicles

When the driver stops the vehicle on an incline where the nose of the car is sufficiently higher than the rear of the car, the system is engaged when the driver's foot is depressing the brake pedal, and then the clutch pedal is fully depressed. Once set, the driver must keep the clutch pedal fully depressed but may remove the foot from the brake pedal. To disengage the system and move the car forward, the driver selects first gear, gently depresses the fuel pedal, and slowly releases the clutch pedal which at a point in its travel releases the braking system, allowing the car to proceed.

Usage

Hill-holder works best for those who are inexperienced with manual shift techniques, or in situations with heavy traffic in steep hilly conditions (as in San Francisco, or Duluth for example).

However the same technique can be accomplished by a driver through the use of the manual parking brake lever, coordinated with the brake, clutch, gear shift and accelerator. This is a standard technique in most countries where manual transmissions remain popular, for example the UK. Cars equipped with a parking brake pedal are not suited for this maneuver unless it is released by hand, for example in the Citroen XM.

References

  1. ↑ the Auto Editors of Consumer Guide. "HowStuffWorks "1939 Studebaker Champion Success"". Auto.howstuffworks.com. Retrieved 2011-01-22.
  2. ↑ "Subaru Drive Magazine: Summer 2002". Drive.subaru.com. Retrieved 2011-01-22.
  3. ↑ "2009 Dodge Challenger SRT8". Driving Sports. 2009-07-15. Retrieved 2011-01-22.
  4. ↑ "2009 Dodge Challenger SRT8". Driving Sports. 2009-07-15. Retrieved 2011-01-22.
  5. ↑ http://www.edmunds.com/fiat/500/2012/long-term-road-test/2012-fiat-500-sport-the-miracle-of-hill-start-assist.html. Retrieved 22 November 2013. Missing or empty |title= (help)
  6. ↑ http://www.thetorquereport.com/2011/12/review_2012_honda_fit.html. Retrieved 22 November 2013. Missing or empty |title= (help)
  7. ↑ http://www.thecarconnection.com/news/1065989_2012-family-cars-with-hill-hold-assist. Retrieved 30 November 2013. Missing or empty |title= (help)
  8. ↑ http://owners.honda.com/vehicles/information/2013/CR-Z/features/Hill-Start-Assist. Retrieved 22 November 2013. Missing or empty |title= (help)
  9. ↑ http://world.honda.com/news/2013/4130905New-Fit-and-Fit-Hybrid/. Retrieved 22 November 2013. Missing or empty |title= (help)
  10. ↑ http://www.roadandtrack.com/car-reviews/first-drives/2013-chevrolet-spark. Retrieved 22 November 2013. Missing or empty |title= (help)
  11. ↑ November 2013 https://www2.smart.com/no/no/index/smart-fortwo/passion.html November 2013 Check |url= value (help). Missing or empty |title= (help)
  12. ↑ http://www.autotrader.com/dealers/dda/index.jsp?dealership_view_name=vincewhibbs&dealer_id=94097&car_id=352340625&address=. Retrieved 22 November 2013. Missing or empty |title= (help)
  13. ↑ http://www.thecarconnection.com/news/1065989_2012-family-cars-with-hill-hold-assist. Retrieved 30 November 2013. Missing or empty |title= (help)
  14. ↑ http://www.thecarconnection.com/news/1065989_2012-family-cars-with-hill-hold-assist. Retrieved 30 November 2013. Missing or empty |title= (help)
  15. ↑ http://www.thecarconnection.com/news/1065989_2012-family-cars-with-hill-hold-assist. Retrieved 30 November 2013. Missing or empty |title= (help)
  16. ↑ http://www.thecarconnection.com/news/1065989_2012-family-cars-with-hill-hold-assist. Retrieved 30 November 2013. Missing or empty |title= (help)
  17. ↑ http://www.thecarconnection.com/news/1065989_2012-family-cars-with-hill-hold-assist. Retrieved 30 November 2013. Missing or empty |title= (help)
  18. ↑ http://mahindrareva.com/pdf/e2oFutureofMobilityBrochure.pdf
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