Does using the parking brake cause the vehicle to have FOUR wheels locked instead of justhe frontwo?.
Thank you.
The parking brake (sometimes erroneously referred to as the “emergency brake”) acts only on the rear wheels of modern cars–including those that are front-wheel drive, rear-wheel drive, and 4 wheel drive. There may have been some cars in the distant past whose parking brake worked on the front wheels, but those days are long gone.
However, if you are actually referring to the “park” function of the transmission, that is a different story. On a FWD car, engaging the park position of the transmission causes the front wheels to be locked in place. Similarly, on a RWD car, “park” locks the rear wheels. And, on a vehicle with permanent AWD, “park” position on the transmission locks all 4 wheels.
Essentially, the drive wheels are the ones that are acted upon by the park function of the transmission, and the rear wheels are the ones acted upon by the parking brake. Which of these are you actually referring to?
The parking brake acts on the rear wheels.
If you park a FWD car in gear (or in Park if it’s an automatic), then, yes, you’ve effectly locked both ends of the vehicle.
It’s my opinion that the parking brake should always be used when the vehicle is unattended, regardless of drive train configuration.
Thanks VD and MC.
When parking on a sloped snow or ice slippery road, I claimed (assumed) that we should also engage the parking brake in case the front wheelslide.
Years ago, while sweeping chimneys, I parked my Toyota Corolla Station Wagon on a customer’s sloped snow-covered driveway so that the back bumper would keep my fully extended extension ladder from sliding out.
On the chimney I heard a sound and saw thathe Toyota slid into the street.
Stranded, I had carefully find my down from the 2nd story roof by another means.
Toyota Corolla Station Wagon!
Those were the days.
While most cars have the rear brakes, or park brake shoes if so equipped, operated by the park brake this is not true of all cars.
Many older Subarus and SAABs have their front brake calipers operated by the park brake. There may be others but I didn’t take the time to think back through all of them but those 2 are definites.
Park doesn’t lock the front (or rear on RWD) wheels so much as it prevents both from turning in the same direction. If you lift one wheel, it will spin in the opposite direction as your car rolls off the jack.
As mcparadise stated, the parking brake should always be used–with one possible exception–in addition to placing the transmission in the “park” position.
The exception to the rule is if you have been driving in wet weather and the temperature is predicted to drop below freezing. In that case, the parking brake should not be applied, as it could freeze in the “on” position, thus making it impossible to move the car the next morning.
However, bear in mind that if you are parked on glare ice, nothing is going to prevent the vehicle from sliding. The combination of a slope and ice is an indication that you should park elsewhere!
If your regular brakes should suddenly fail, then you will use what you have. For a short period of time the parking brake will be the emergency brake.
I can guess why the semantic games are played with the description of the “Reserve?” brake. If the regular brakes fail and the “Emergency” brake does a very poor job of stopping the vehicle, as would be expected, someone will smell money and will find a trial lawyer to sue a car maker for an inadequate “Emergency” brake. So there you have it, it’s a “Parking” brake.
The “Parking” brake actuates the rear wheel brakes, whether front or rear drive. I have never seen car with a parking brake that actuated the front brakes. Possibly a few may have had a parking brake as part of the transmission.
On a car with rear drum brakes, FWD, AWD, 4WD all use the rear brakes for “parking brake”. There are some cars, older Saabs for one that the parking brake works the front disk brake.
A Toyota Camry Hybrid could be a whole other animal. There are lots of unique aspects of the braking systems for a hybrid. My guess is it works the rear wheels. Drive yours on a dirt road and at 5 mph pull on the parking brake hard and see which wheels leave skid marks in the gravel.
I’ll have to get under it (in the gutter) and see if brake cables go to the rear wheels.
Because I do so much dynamic braking (gentle braking), the disk brakes have hardly any wear!
Nice for descending mountains with “brakes” constantly applied.
Older Subarus, be they FWD/4WD/AWD, all used the front disc brakes as the park brake mechanism even on rear drum models.
How old are we talking about?
I am familiar with the workings of Subarus going back as far as 1995, and as long ago as 15 years ago they used the rear brakes as a parking brake.
My 96 SAAB two stroke used the rear wheel “parking” brakes to help the fwd over steer on turns when ice racing…great for reversing direction on ice too.
This is ancient history and I don’t remember the year of changeover but it was in the early 90s I think. Up to that point all Subarus used the fronts as a park brake. All of the SAABs used the fronts as a park brake even on rear disc cars.
My memory is fuzzy (very, very) on this but it seems like the older Subaru FF1s also used the front brakes for parking and these were drum brakes that were mounted inboard on the transaxle.
Point being that a blanket statement that all cars and/or models use the rear as a park mechanism is not correct.
There was another vehicle that had another really oddball method of applying a park mechanism but I cannot for the life of me remember what it was. It seems like it was a European car of some sort; Renault, Peugeot, etc.
Maybe in later SAAB years and/or different models (the early 99). After driving many a tractor which have only rear mounts and brake well only in 4wd, I see your point.