I have an old Toyota in which the handbrake wire is broken. I have been using the car for few months now and I don't really want to spend more money on it. I now put the car in park and that is it and I had an argument with a friend on this matter. My questions are:
do I really have to replace this wire knowing that I use the car to commute and short trips?
could this affect the brakes of the car and cause it to fail faster than it is supposed to?
is there a better practice?
Assuming it is an automatic transmission using park is safe, there is a park pawl in the transmission that mechanically locks the output shaft, actually better than a parking brake.
The slight roll forward (or backward depending on incline direction) is normal for an automatic park pawl, the movement of the car rotates the output shaft slightly to engage the pawl.
Only downside is if you are on a steep grade it might require some effort to take it out of park due to the load on the pawl, but does not hurt anything to do so.
generic image of park pawl
According to Wikipedia, this is not advisable:
Most vehicle manufacturers and auto mechanics do not recommend using the transmission's parking pawl as the sole means of securing a parked vehicle, instead recommending it should only be engaged after first applying the vehicle's parking brake. Constant use of only the parking pawl, especially when parking on a steep incline, means that driveline components, and transmission internals, are kept constantly under stress, and can cause wear and eventual failure of the parking pawl or transmission linkage. The pawl might also fail or break if the vehicle is pushed with sufficient force, if the parking brake is not firmly engaged. Replacement can be an expensive operation since it not only requires removing the transmission from the vehicle, it's usually the first component to be installed in the gearbox case during a complete overhaul rebuild.
So while it may be safe, you risk more expensive damage to your vehicle by relying on the parking pawl alone.
If you live in the UK, this will fail your annual MoT test. (For the benefit of non-Brits, the Ministry of Transport requires a standard annual roadworthiness test for all vehicles.) Other countries may have similar legislation - YMMV depending on where you are.
Whilst leaving a car in Park (auto) or in gear (manual) will prevent the car from rolling away, in the event that the primary braking system fails, you will have no means of stopping the car. This is of course the other purpose of the handbrake.
A factor no one mentioned might be safety with children. We have a 2005 Rexton which our 2 year old managed to put into reverse with the car off! The car rolled backwards and thank gd was stopped by a boulder before falling off a 2 meter drop.
Although I'm not sure an automatic should be able to be put into gear without at least the key in the ignition, an engaged parking brake would have prevented this situation.
(We now park the car only on flat ground, engage the parking brake, and lock the car.)
Funny, the handbrake was designed as the assistance brake to deal with confusing lack of 3rd leg when starting on a slope.
Using it for parking is not recommended, I've read a lot of warnings, during winter it can easily be broken that way. Everyone recommends parking on a gear.
Go find some steeper slope and test when there's null traffic, if you can stop&start there without problems. Some people have no issues, some will find it hardly possible to start even on a moderate slope without a handbrake.
I'm going to pretend for this answer that putting it in part does not imply an automatic transmission [because automatic transmission is well covered].
With a manual transmission this is safe for reasonably level ground. Engine compression alone will hold indefinitely for a considerable amount of force. A hill of more than about two degrees is too much however. If you worry about it, block a wheel.
In the event of a brake master cylinder failure, the parking brake (or EMERGENCY brake) will still cause the brakes to grip, while the brake pedal might go right to the floor. This means that if you don't have a working e-brake, you risk potentially losing braking ability if something goes wrong. Most modern cars have two brake cylinders so that if one fails, the other will allow you to stop (one for each side of the car usually). However, older cars typically have only one brake cylinder, and if this goes or if you have an issue with your brake lines, the e-brake is there to save your ass!
