Auto parking brake

[jonmacan]

Hmmm.  I think 'short term' in unfamiliar environments I'd always apply the handbrake - if only to stop the 'roll-back' when releasing the footbrake - it's only a few inches but ...

my findings also..

[Wing Commander]

- if only to stop the 'roll-back' when releasing the footbrake -

Yea, that's the very American thing. You always see it on US TV shows and film :)

[Andy352]

Just been out for a wee test.  Firstly I confirm the parking brake releases automatically when starting to move in either forward or reverse.  So we do not ever have to manually release the brake.  Wow so that saves us a lot of effort in pressing the little button.
I am now confused about how or when the brake automatically engages when turning off the engine.  A few days ago the brake came on automatically although I do not know what position the selector was in when I turned off the engine.  Today I could not get the brake to engage automatically no matter which position it was in (although I did not try doing it in the R position).





So there must be some other factor coming into play.  But what?

Handbrake only releases automatically when driving off if seat belt is fastened and driver's door is closed.
Handbrake will automatically engage if gearbox is in D or R, ignition is on and driver's door is opened.
Andy3522016-03-10 13:01:27

[BrianR]

Handbrake only releases automatically when driving off if seat belt is fastened and driver's door is closed.
Handbrake will automatically engage if gearbox is in park, ignition is on and driver's door is opened.

'Good to know' says

The electric parking brake engages automatically if PDK selector-lever position D, R or M is selected when the vehicle is stationary and the driver's door is opened. The indicator light on button and the brake warning light in the instrument panel come on.

I would not expect it to be needed in P, altnough it is unclear exactly what that does (in a conventional automatic if locks the transmission).

Of course, GtK is only currently of MY2016 cars, and AFAICS those sold in the USA at that. It is possible that the behaviour differs by model (according to GtK, auto stop-start does).

[goron59]

Most double clutch gearboxes (and auto boxes in general) employ a pawl mechanism to lock the transmission output to the transmission structure or casing, preventing the wheels from rolling.

The pawl can break however under stresses and be very expensive to fix. Certainly not cheaper than changing your pads!

In ye olde days, the parking brake pressure was applied by the hand brake lever connected via a cable and held by a ratchet in the handle. The ratchet could fail. Cable to stretch or break. So the use of the pawl was considered best practice and even a legal requirement in some states in the US. Parking on a hill also mandated turning the wheels into the curb.

These days, of course, the parking brake is electro-hydraulically applied so chance of failure is near zero.

But old habits die hard!

goron592016-03-10 09:44:32

[Chilgrove]

Thanks for all replies. I now think for me to have the brake applying automatically I must have had the selector in D, R or M when I opened the door. Great, question answered!
I also agree about thinking about what kind of repairs would I rather do; gearbox or brake pads. It does make more sense to use the brake.

[Wing Commander]

Am I going mad? Isn't it D, R, P & N (not necessarily in that order) as the positions for the gear selector being Drive, Reverse, Park & Neutral. What's this M all about...?

[Tall Phil]

Manual?

[Wing Commander]

Just gone online & found a PDK video from Porsche. Definitelty says 'N' and not 'M'

[Caster]

Talking of old habits - does this mean you can't open the drivers door to get a better view when reversing?