Turning the car off before letting foot off the brake pedal question...

[92saturnsl2]

Originally Posted by Number_35
Chrysler was late to put in an interlock to prevent the transmission being shifted out of P without pressure being applied to the brake pedal. I think most other manufacturers were already on board.)


This has been a requirement of the FMVSS for many years prior to 2004. This is not a Chrysler problem.

https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/tp-114-04.pdf

 

[Garak]

Originally Posted by Number_35
A lot of Fords, I'd say around 40 years ago, had a nasty habit of dropping out of P into R spontaneously. It was always good practice to use the parking brake with them.

Not even going that far back, one should exhibit some caution. My 1984 F-150, you have to be a bit cautious with. It won't drop spontaneously, so much, but is easy to bump. Now, the LTD I had that was only a year older, you really had to be giving it a clear, distinct pull towards you, then the push down to get it out of park. Doing so accidentally would have been a bit of a stretch.

 

[DriveHard]

Couple thoughts from someone in the rust/freezing belt...

Don't put the parking brake on below freezing...ESPECIALLY if previously driving on slushy roads
Don't forget to actuate the parking brake on at least a monthly basis, or it will freeze up and not work/release if used

With that said...
The parking brake is pretty much a waste of an item in Auto trans cars. The parking pawl is designed to "skip" if engaged at too high of a speed, and strong enough to lock the wheels and skid at a designed speed...so simply rolling into it from a stop, or concern it won't hold a car on a hill are pretty much a waste of time. My previous employer was a major supplier of parking pawls, and the design and testing that goes into them is quite impressive for such a simple little device. If I was driving a rental car that I knew was using one of our pawls, I wouldn't hesitate to throw the car in park on the highway and give it a test myself. Also led to a fun few drives/bets with friends in rentals....hehehe, scared a few...

 

[PimTac]

" If I was driving a rental car that I knew was using one of our pawls, I wouldn't hesitate to throw the car in park on the highway and give it a test myself. Also led to a fun few drives/bets with friends in rentals....hehehe, scared a few..."




A good reason not to buy a used rental car.

 

[DriveHard]

Originally Posted by PimTac
" If I was driving a rental car that I knew was using one of our pawls, I wouldn't hesitate to throw the car in park on the highway and give it a test myself. Also led to a fun few drives/bets with friends in rentals....hehehe, scared a few..."




A good reason not to buy a used rental car.


If that is how you feel...I knew they were designed for that with no damage. I would have done it in my own car, but didn't have a trans. in my stable at the time with one of our pawls.

 

[CR94]

Originally Posted by 92saturnsl2
Originally Posted by Number_35
Chrysler was late to put in an interlock to prevent the transmission being shifted out of P without pressure being applied to the brake pedal. I think most other manufacturers were already on board.)
This has been a requirement of the FMVSS for many years prior to 2004.
That requirement arose as a result of the Audi unintended acceleration saga a few years earlier. It's still annoying to have to step on the brake in order to move forward.

 

[69GTX]

Originally Posted by Wolf359
Never thought of it much. Always throw it in park and then shut the car off, sometimes with or without foot on the brake. Don't bother setting the parking brake. Never had an issue with a broken parking pawl. Even on cars with 200k+. A solution in search of a problem.


Ditto. For the past 46 years. Never broke a pawl. But I have had parking brakes seize up on me in colder weather. And just stopped using them in automatics back around 1979.

Once the engine is off.....I feather the manual brake and let the car slowly load on to the pawl parking. I do try to avoid steep hills when parking. In those situations I'll turn the wheels as well. The parking brake in my manual transmission does get used most of the time.

 

[aquariuscsm]

I remember seeing carb'd cars from the late 70s-early 80s that would keep on "running" if you didn't turn off the engine while it was still in drive. What makes that happen?

 

[Hall]

I've heard that called "dieseling". No idea why it happens....

 

[spasm3]

Originally Posted by aquariuscsm
I remember seeing carb'd cars from the late 70s-early 80s that would keep on "running" if you didn't turn off the engine while it was still in drive. What makes that happen?


Dieseling. Fuel keeps igniting from hot carbon in the combustion chambers.

 

[DBMaster]

I had a 72 Pontiac that used to diesel. You could even press the gas pedal and the dieseling would increase. Ah, the bad old days.

 

[PimTac]

Originally Posted by DBMaster
I had a 72 Pontiac that used to diesel. You could even press the gas pedal and the dieseling would increase. Ah, the bad old days.




Those were bad days indeed. Crappy cars everywhere.

 

[exranger06]

Originally Posted by KeithKman
Quick question - my father has developed a habit of turning the car off before he lets his foot off the brake pedal and when he releases his foot off the brake pedal the car will either roll forward or backwards before it stops. Sometimes he will release his foot off the brake pedal quickly and the car will jerk forward or backwards depending on the incline or decline. Is this a bad habit? I've never met anyone else that has done this. I was just curious how bad this is for the transmission or various other parts on the car, if at all.

When I come to a stop and put the car in park I usually will slowly let my foot off the brake until the car comes to a stop and then turn the car off. I thought everyone did it this way, guess not.

The rolling forward or backward has nothing to do with turning the car off before taking your foot off the brake pedal. It has everything to do with not using your parking brake. The car will roll a few inches regardless if the engine is running or not. But not if you use the parking brake. Is letting it roll bad for the car? I've never heard of anyone having problems because of it, but I don't like it. I always use the parking brake if I'm parked on any incline. I don't like having the parking pawl as the only thing preventing the car from rolling down a hill, and it's not meant for it.
Originally Posted by eljefino
I never liked automatic cars that surged forward 3 inches after being put in park and having the service brake released. What if I "precision parked" and need those inches?

...Maybe use the parking brake in those instances?

Originally Posted by 92saturnsl2
Originally Posted by Number_35
Chrysler was late to put in an interlock to prevent the transmission being shifted out of P without pressure being applied to the brake pedal. I think most other manufacturers were already on board.)


This has been a requirement of the FMVSS for many years prior to 2004. This is not a Chrysler problem.

https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/tp-114-04.pdf

The requirement was only to prevent shifting out of park if the engine is off and the key is out of the ignition. There was no requirement for an interlock that would prevent shifting out of park while the engine was running until 2010. I had a 1994 Ford Explorer that could shift out of park when the engine was running without touching the brake pedal.

 

[PeterPolyol]

MILLIONS of automatic vehicles are routinely 'hung' on the parking pawl with absolutely zero fore- or afterthought. Whether you 'hang' it with the engine running or not makes a lick of difference. Also as it relates to shift interlocking, it's coincidentally more difficult to shift out of P with with a high standing torque against the pawl tooth. This is one those "Tightening fuel cap: 2 clicks or 3?" kind of issues

 

[supton]

Originally Posted by exranger06

Originally Posted by eljefino
I never liked automatic cars that surged forward 3 inches after being put in park and having the service brake released. What if I "precision parked" and need those inches?

...Maybe use the parking brake in those instances?



I've had one or two vehicles with perfectly working parking brakes that weren't worth the metal they were made of. *cough* all three of my Toyotas *cough* For some reason most (all?) of my vehicles that used drums for parking brake seemed to be inadequate at holding the vehicle on a hill.