Parking Brake verses tranny's Park?

Your mechanic is full of it. And I'm not referring to wisdom.

The parking brake generates no additional heat when you're parked. I don't know where he got his information but I'd start looking for a new mechanic.

That's one of the more ridiculous things I've heard lately. (yes, surprisingly, there has been more ridiculous things said in the past two weeks).

If you don't use the parking brake the linkage can become rusted and the brake won't work. Then your mechanic will ask "Shall I free up the parking brake?" and charge you for it. :)

PS. You should grease the parking brake linkage. I think it's called a "clevis" pin. It's on the outside of the brake drum. Had to replace mine.

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Also, isn't the "Park" on an automatic transmission about the same as "neutral" on a manual transmission? If so it's not going to stop the car from wandering off on it's own with nobody in it, like the parking brake will.

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Nope, there is a manual stop in Park. A parking pawl latches into a cog. It is a much more secure lock that parking brakes usually are. But as another poster mentioned, some braking systems ONLY adjust and stay operable if the parking brake is used judiciously.

I can see the mechanics reasoning in some limited situations. If you had been using your brakes a lot, such as on a long steep descent then if the brakes pads were very hot you would get a localised heating applied when applying the parking brakes.

However, the park position in auto transmissions is not intended to support the weight of the vehicle and may fail. Therefore use your parking brake. It is a cheaper repair than a failed transmission and body work.

: Mechanic told me to never use the parking brake unless I like warped and : grabbing brakes. Said just to use the Park on the trans. selector. : : He said, aside from improperly torqued wheels, that the parking brake : applies to much localized heat to the drum or disk and creates a hard spot : where the brakes will grab and slip and/or warp and you'll lose that new car : stopping smoothness in short order. None of which would ever fall under a : warranty. He said only to use the parking brake after a good two hour cool : down (like I'll wait that long). : : Any truth to this, or is this guy a victim of mad cow?

Your mechanic is right. Setting a hot brake pad against a non-moving drum will create a hardened spot which may need to be turned down to keep the feel nice. Warpage is a real concern too as would be squealing brake pad surfaces that are compressed for a length of time and become glazed. Let them cool.

See

Mack

This is a case when theory and practice collide...

Theoretically, your mechanic is right - you could create a set of circumstances where putting on the parking/emergency brake when the system is very hot could create problems. When racing, we try very hard to not put on the brakes just as we stop the car after a session, we let it roll to a stop so that the pads get knocked back just that little bit so that the rotors are less likely to warp from a hot spot. But practically, you will not have your brakes anywhere near that hot and there is next to no chance that anything bad will occur if you just drive up normally, stop, put transmission in park and pull on your emergency brake. It's excellent practice to do exactly that every time you park.

Brian

"Never" is the wrong word, a little common sense is needed. If you are parking after a prolonged round of high speed braking where the rotors are really hot, it would be wise to not set the parking brake 'til they cool, but after normal driving go ahead and use the parking brake.

Some rear disc brakes depend on the parking brake to adjust the caliper piston, prolonged non-use of the parking brake can result in a low brake pedal due to excessive travel of the piston.

Wrong.

If you have heated up the brakes by using them hard just prior to parking (as might be the case, for instance, if you live at the bottom of a long mountain road), then you'd want to wait a few minutes for the brakes to cool before you apply the parking brake. But in normal everyday driving, the correct procedure is to set the parking brake -- it will not warp the brake rotors or drums, it will not cause "hot spots" or "hard spots", it will not have any negative effects. But, it *will* keep the parking brake adjusted and prevent the cables from seizing.

Absurd.

MOOOOOOOOOOOOOOO!

------------ Alex

I doubt anyone gets their brakes hot enough for this to happen. However, race drivers can warp the rotors on their race cars by holding the foot brake on during pit stops. The VW bug could warp the rear drums if the parking brake was applied to hard while the drums were hot. They straigtened out after a few applications of the foot brake.

applications

Well, driving through the mountains in Colorado, pulling a pop-up camper, I have had the discs glow red... Is that hot enough?

When I stopped, the brakes were so hot that the fluid in the calipers boiled.

Believe it or not, I got back in the car after letting it cool thoroughly, and continued the trip (this time using my transmission more than I did my brakes.) Never a problem.

The rear brakes (the subject brakes here) were red? Did you apply the parking brake? I had the front brakes on our transporter catch fire coming down the East side of Yosemite Park. What is the name of that Pass? A nervous customer did the same thing on his Bentley on the way to my shop-on flat ground. My first comment was to let it burn, the car's insured.

This was a four wheel disc system. All four discs were glowing red. I probably did not apply the parking brake when I got to the valley town, just locked the parking pawl.

Honestly, at that time I was new to driving in mountains and didn't use the low speeds of the transmission to slow our descent. Brakes never faded, so I didnt realize what I was doing for a while. I learned quickly.