The front brakes are almost always doing the majority of the work. On some cars the rear brakes are considerably smaller, or are actually drum brakes. Also the (non-ABS) systems are normally balanced with a considerable front bias.
when you say the brakes get lock is like on the old cars without abs that they lock the wheels until you release the pedal right? could it be posible that the brakes get lock and even if you stop pressing the pedal they are not able to get unlock is that what you mention as lock?
This has to be one of those trick questions,right?
When I say “locking the brakes” it means the tires are no longer spinning and releasing the brakes will allow them to spin again, precisely what ABS prevents.
Elementary physics. If I slam on the brakes WITHOUT LOCKING THE WHEELS I get thrown forward into the seat harness, and the car nosedives, trans ferring weight to the front wheels. In addition, my wife curses me for trying to stop so fast.
WOW…you get bored in just a 60 mile drive…very very short attention span. What will you do when you have to do some REAL driving???
“my dad got into a serious accident on a downhill”
Jorge, you need a course in defensive driving and emergency manoeuvres. In an emergency with the unlikely case of total brake loss, you can stop the car by throwing it into reverse, thereby wrecking the gearbox, but saving your neck. Your father probably had a car without the dual braking system, which virtually eliminate complete brake failure, unless you are totally out of fluid.
On older cars, you turned the key off and first tried low gear, which would slow you down fast. I did just that in an older Chevy when a rear leaf spring snapped and cut through the brakeline, making me lose the brakes. It was on a steep downhill slope with a T intersection at the bottom. The handbrake on this old car was not working very well.
I learned to drive in the army and there was a lot of emergency training.
So, if you are about to have a serious accident due to brake loss, throwing the car in reverse will likely stop you quicker than pulling the handbrake. But I would do both.
Commuting 120 miles a day isn’t “real” driving? This guy is spending at least 3 hours a day behind the wheel both before and after working 8 hours. That has to be hard.
I did 71 miles each way every day for 5 years…My commute is better now…I only drive 47 miles each way.
But what I meant was not so much as commuting…but when you take a LONG trip say 5-10 hours!!
I don’t see HOW the rear brakes can be doing MOST of the work…Nor do I see how that is even desirable. When you brake the weight shifts to the front of the vehicle. That’s why the front is doing MOST of the work. And since the weight is now mainly in the front…having the rear brakes doing extra-duty is NOT good for the car or controlling the car. An old trick some of us use to pull as teenagers…was to apply the parking brake at 30mph and turn the wheel…it would cause the rear-end to spin around…Looked real cool…you see it on TV all the time. I think Jim Rockford copied our moves. But you sure didn’t have GOOD CONTROL of the car during that maneuver.
The car doesnt engage first gear at any speed above 23 MPH even with the cluth fully press and reverse is the same the stick will just not go in at any speed beyond 5-6 MPH
The determinants in this are the coefficient of friction of the rear brakes vs the Cf of the front brakes, the Cf of the rear tires vs. the Cf of the front tires, and the weight on the tires in a given braking situation.
If one is in a pickup driving a dead African elephant to the dump, and one’s front tires are bald, and the dump road is soft sand, then it’s entirely possible for the rear brakes to be doing most of the work. The fronts would simply lock up and slide along for the ride.
But normally a braking system is designed to make the best use of the tires over which the weight transfer goes, and since the entire mass is above the frictional point that’s stopping the vehicle (the tire patch on the road) the frictional point acts like a fulcrum and everything rocks forward. Inertia is trying to keep the mass above the tire patch moving while the tire patch is trying to slow it down.
Jorge, I assumed you had automatic. With a manual, as others pointed out, gear down and you will absorb a lot of the car’s energy. Then pull the handbrake.
Your putting stress and strain on the ‘brakes of last resort’, which is never a good idea. They could fail due to wear when you absolutely need them. Also, the e-brake DOES NOT ACTIVATE THE BRAKE LIGHTS!!! How is the guy behind you going to know your slowing down before you take up residence in his radiator?
Bad idea, just a bad idea. Stop that practice now.
If you have rear disc brakes with a parking brake drum incorporated in the disc, you are damaging the parking brake and really wearing it out. You never said what car you are driving. If your vehicle has anti-lock brakes, you may have disc brakes in the back and you are halfway to no parking brake if you do have the expensive combination of rear disc-drum.
The best thing about this is that the brake lights don’t come on and the guy tailgating you while dialing his cellphone and eating a burger will be unaware that he is about to hit you and won’t have to hear his wife make that gasping sound that so bothers him until after the impact. Brake lights are way over rated anyway.
"and balance the pressure so the wheels doesnt lock up "
If you can lock up the wheels with a hand operated parking break, you are certainly a lot stronger than I am. Try it some time when it would be safe. No one should count on the parking brake to stop you in an emergency.
Agree; as long as the center of gravity of the vehicle is ABOVE the centerline of the front wheels, the car will nosedive. If you had 60" tires, you could have the center of gravity below the centreline, and the car would squat rather than nosedive. In the 50s GM started building an anti-dive feature in it’s front suspension by tilting the line throught the upper and lower ball joints backwards. This reduced the dive somewhat, but, of course, could not eliminate it.
my dad got a serius accident on a downhill like 15 years ago the car brakes overheat and the car was not able to stop at all
I can tell you exactly what happened. He rode the brakes on a long downhill, rather than shifting down to let the engine to the braking. This overheated the brakes, which boiled the brake fluid, which led to total loss of braking.
I learned the hard way a few years ago that the parking brake ain’t worth squat for stopping a moving car. I had just broken my left leg and couldn’t use the clutch, so I tried getting to a phone and medical help by using my right foot for gas and clutch, and the parking brake for stopping. I tried to stop at the end of a side road and ended up halfway across the main road before stopping (and forced a truck to swerve around me!). A parking brake has very, very little stopping power, and is useful only for… parking. And yes, after that I rented a car with an automatic for the duration.
I see you’re a Books On Tape fan, uh?
Here’s another suggestion. Go to the Music section, and get a few CDs from Black Sabbath, Iron Maiden, AC/DC, or Led Zeppelin. Maybe throw in some vintage Megadeth and Metallica while you’re at it. No more boredom.