IMHO. Putting on the parking brake is a good habit to get into.
I just traded in a manual trans car for an automatic. I ALWAYS put the parking brake on in the manual. The new car will not let you take the key out of the ignition if it’s not in ‘Park’. A good thing.
My new car has a foot parking brake that you have to press again to release.
I think, that the prawl is disengaged when you are moving, allowing you to sort of use it as a regular brake. It should be.
Don’t try this at home.
I live on a gravel road. I’ll give it a try in the morning.
While I admire your pursuit of knowledge, I must say the following: DO NOT DO THIS!
Putting a car into park while moving can be a very expensive mistake.
Look, Park is not a brake. I know that it keeps the car from rolling, but it is not a brake. Brakes can be applied a little or a lot. Park is digital nothing or everything.
Picture a gear with teeth all around the outside spinning with a fair amount of force. Picture what would happen if you jammed a piece of steel (the pawl) into that spinning gear. :eek:
So what will happen if you toss your car into Park when it is moving?
There are three possible outcomes here. All are bad to a greater or lesser degree. When you shift the car into park while moving you will hear a loud nasty grinding noise from the area of the transmission. The fun (bad) part comes next.
When the Park Pawl engages it, it does so with so much force it snaps the pawl off. It is now major transmission repair or replace the transmission time.
The pawl engages the output shaft and stops the shaft from turning. Your drive wheels instantly stop rotating. The best outcome you can hope for is flat spotted tires. If you are cornering at the time, there is a possibility of a loss of control. Shortest straightest line to the biggest fattest tree.
Parking pawl jumps along the output shaft for several seconds and engages when the speed is low enough. No problem right? Wrong. All that grinding put metal shavings into the transmission. Automatic transmissions hate metal shavings, and oft times don’t react well to them. This event could cause a valve failure at a later date. Again it is time to visit the transmission shop.
Getting back to the OP’s last question. Less that 1 out of 1,000? Way less, probably less than Gary T’s 1 in 10,000. But there are a couple of things to keep in mind. First off if you need the parking brake because Park did not engage you will need it bad. I heard of a case where a driver parked on a very steep hill (10%+ grade) person started to get out of passenger side. Driver puts car into Park, pawl does not grab due to gravity accelerating the car too fast, passenger gets run over. BTW steep hills are the one time I always use my parking brake. Secondly what happens if you leave the parking brake on and drive away (Yes this is possible on many cars) The rear tires will skid along the pavement flat spotting them, and eventually a flat will occur. (Front wheel drive) True story, customer has car towed into dealership. Two complaints 1. Car has no power. 2. Both rear tires are flat. Yup they drove off with the parking brake on. They did not notice the word BRAKE in the instrument cluster. Or even worse than that, you almost get the brake fully released. It is only on a click or two. Now the rear brakes are dragging, and you will burn more gas, and wear your brakes out in record time. :smack:
I’m an advocate of always using the parking brake, except in one particular circumstance.
I slushy/wet during the day, freezing at night weather. At least on fords, water/slush will find it’s way between the parking brake cable and it’s sheath. It will then freeze at night, and if you set the brake, it won’t release.
Setting the brake is such an engrained habit, that I’ve had to get out the heat gun a few times to release the brake.
The driveway where I tend to park at night is steep enough that the brake is desireable, so on those slushy days I use a chock.
I would think an emergency brake would actually be desilgned to work for a major problem-----like the tranny slipping into reverse with the car running when you are out of the car.
(Actually does happen you know with older cars)
All cars I have ever owned failed this test miserably. Do a little better in drive. But no big huzzahs there either.
So why won’t the average emergency brake hold a car from moving when in gear?
Uh, Rick, he’s not talking about putting it into park. He’s talking about the parking brake. The pawl he refers to is on the parking brake mechanism, and he thinks it may be automatically disengaged when the car is shifted into gear (a feature that goes back to the 60’s) or starts rolling. That’s what he’s going to test.
All your comments are correct and good advice, they just don’t apply to enipla’s plan.
The manufacturers don’t call it an emergency brake. They call it a parking brake. It’s not designed to do stop a moving car, it’s designed to keep a stationary car from moving.
Even so, a parking brake in good condition and properly applied can keep a car from moving in gear under normal accelerator application, past the point where any driver who isn’t brain-dead would realize something is definitely not right. Now, there may be some cars where the parking brake isn’t quite that effective, but I’ve seen plenty where it is.