Is there an "Extra" Parking Brake Step or Not? Weird.....

[SpudLime]

So. After reading this. Clicking the button just puts it in Park without any brake. Similar to an ICE car. If you want the emergency brake, you need to hold in the button.

Interesting. Every ice car I always use the emergency brake. I was taught to not just put it in park as the rocking of the car on the transmission wasn’t good long term and to always use the emergency brake.

On my model S, I assumed the brake was engaged when putting it into park.

 

[gregincal]

So. After reading this. Clicking the button just puts it in Park without any brake. Similar to an ICE car. If you want the emergency brake, you need to hold in the button.

Interesting. Every ice car I always use the emergency brake. I was taught to not just put it in park as the rocking of the car on the transmission wasn’t good long term and to always use the emergency brake.

On my model S, I assumed the brake was engaged when putting it into park.

No, no, no. Park in an ICE holds it in place with the transmission. There is no transmission in a Tesla. Putting it in park engages the parking brake, or it would roll away.

 

[GregRF]

So I just went out to my car to experiment with this. In a very quite garage with the Radio and AC off I switched from drive to park, and then held the P button until the parking brake indicator came on.
The sound of the parking brake engaging is very different sound from when you initially put the car in park. The parking brake sound is a distinct short clunk vs. more of a whirring noise when you put it in park.
So the question is what's the difference between being in park (P) vs. having the parking brake engaged?
I would think like most automatics you still wouldn't normally need to engage the parking


I'm not sure the above is true.
I did a test in my very quiet garage, and there is definitely a separate distinct sound that occurs at the same time that the parking brake indicator is displayed after the second press. It is a distinctive quick clunk. The sound when putting the car in Park (P) is much different. I'm not quite sure how to describe this sound. It is more of a whirring sound of longer duration.
To me it seems analogous to putting an automatic car in Park vs. setting the separate emergency/parking brake.
Having said that I don't know what the Tesla actually does when you first put it in Park with the first tap of the P button.

Interesting. Does it sound any different when disengaging Park between the two scenarios? When first putting the car into drive, I can here the whir of the parking brake disengage. Does it sound differently when the parking brake is manually set?

 

[TT97]

Somebody had an incident caught on a security cam of their steep driveway where one set of wheels (I forget if front or rear) were on ice and the car started sliding because they didn’t engage the full “press and hold” Park function.

So I think there is some value in knowing which wheels get locked, albeit this was a very odd edge case.

Parking Brakes are only on the rear wheels.

One of the main benefits of electronic parking brakes (other than weight savings) is that the car has the ability to automatically engage the brake - it makes no sense that the brake doesn't engage automatically (especially considering the manual states the brake engages automatically and has zero reference to pushing park button again to engage).

My MB had electronic parking brakes and sometimes would not disengage right away when putting in the drive/reverse. The car would hold firm so I would instinctively push the accelerator a little more only for the brake to disengage causing my car to lunge (and of course, this would usually be in my driveway). I kept waiting for an OTA from MB to fix it, but it never came.

 

[Eddyrelik]

So I just went out to my car to experiment with this. In a very quite garage with the Radio and AC off I switched from drive to park, and then held the P button until the parking brake indicator came on.
The sound of the parking brake engaging is very different sound from when you initially put the car in park. The parking brake sound is a distinct short clunk vs. more of a whirring noise when you put it in park.
So the question is what's the difference between being in park (P) vs. having the parking brake engaged?
I would think like most automatics you still wouldn't normally need to engage the parking


I'm not sure the above is true.
I did a test in my very quiet garage, and there is definitely a separate distinct sound that occurs at the same time that the parking brake indicator is displayed after the second press. It is a distinctive quick clunk. The sound when putting the car in Park (P) is much different. I'm not quite sure how to describe this sound. It is more of a whirring sound of longer duration.
To me it seems analogous to putting an automatic car in Park vs. setting the separate emergency/parking brake.
Having said that I don't know what the Tesla actually does when you first put it in Park with the first tap of the P button.

Yes! I’m not crazy! HahahA. The mystery continues though...

 

[gregincal]

So I just went out to my car to experiment with this. In a very quite garage with the Radio and AC off I switched from drive to park, and then held the P button until the parking brake indicator came on.
The sound of the parking brake engaging is very different sound from when you initially put the car in park. The parking brake sound is a distinct short clunk vs. more of a whirring noise when you put it in park.
So the question is what's the difference between being in park (P) vs. having the parking brake engaged?
I would think like most automatics you still wouldn't normally need to engage the parking

I tried the same experiment and couldn't hear any additional noise when the indicator came on, but the whirring noise is definitely the sound of the parking brake engaging. Unlike an automatic ICE car you most definitely need to engage the parking brake.

As far as I know the only reason for holding the park button is that pressing the park button won't engage the brake if you are moving, whereas holding it will. Perhaps there is some additional difference, but putting it in Park most definitely engages the parking brake.

 

[Lasairfion]

I'm going to guess that putting a Tesla into 'park' is simply telling the drivetrain to stop moving. I would hazard a guess that this would only affect the wheels to which a motor is attached. So maybe if that set of wheels were on ice, then the car might move since the other wheels would have free movement.

Pressing the park button and holding it to show the additional park indicator is likely using actual callipers to grip the wheels. This video shows a car being dragged to a halt by putting them on at speed. Rather like yanking your handbrake (emergency brake) on in a regular car, only smoother because electronics.

So I reckon putting it into park is like leaving a regular manual car in gear or a regular automatic car in park. Whereas holding down park is like putting on the handbrake (emergency brake).

 

[North75]

Interesting. Does it sound any different when disengaging Park between the two scenarios? When first putting the car into drive, I can here the whir of the parking brake disengage. Does it sound differently when the parking brake is manually set?

I couldn't tell any difference in the disengaging when putting the car into drive. Its possible that the whirring noise is drowning out the other noise. The second noise I heard when the "parking brake" indicator comes on sounded like a solenoid valve energizing to me. (or at least it had a similar sound to a solenoid valve) A lot of times solenoid valves don't really make any noise disengaging... only when they are engaged.

 

[gregincal]

I'm going to guess that putting a Tesla into 'park' is simply telling the drivetrain to stop moving. I would hazard a guess that this would only affect the wheels to which a motor is attached. So maybe if that set of wheels were on ice, then the car might move since the other wheels would have free movement.

Pressing the park button and holding it to show the additional park indicator is likely using actual callipers to grip the wheels.

Your guess would be wrong. Putting a Tesla into 'park' uses actual calipers to grip the wheels. I'm pretty sure there are parking brakes only on the rear wheels.

 

[animorph]

So the guys that are listening to what's happening, what happens if you long-hold the button to set the parking brake first and then short-press the button to put the car in park? I wouldn't be surprised to hear some motor whine while the car tries to apply the parking brake a second time. Also, if you only short-press the park button, can you then get out and push the car easily?

 

[North75]

So the guys that are listening to what's happening, what happens if you long-hold the button to set the parking brake first and then short-press the button to put the car in park? I wouldn't be surprised to hear some motor whine while the car tries to apply the parking brake a second time. Also, if you only short-press the park button, can you then get out and push the car easily?

I'll have to try this. I did try to push the car after short press only and its definitely not moving. The brakes (at least rears) seem to be engaged. I saw another video that showed the parking brake for model S. It looked like there was a small motor that spun some gears to engage the caliper (not quite sure how it all works) My guess is that the "whirring" noise is this motor spinning. I'm wondering if there is some kind of additional locking pin or something that can engage to hold the first motor in place so there is absolute no chance of the brake loosening over time. That's my guess anyway.

 

[animorph]

Just a thought, but it seems possible that when used as a parking brake it uses less force than when used as an emergency brake. Hence it is tightening up a little more when long-pressing the button.

 

[SpudLime]

Just a thought, but it seems possible that when used as a parking brake it uses less force than when used as an emergency brake. Hence it is tightening up a little more when long-pressing the button.

That is the only thing logical thus far after participating in this thread. Lol

 

[North75]

So the guys that are listening to what's happening, what happens if you long-hold the button to set the parking brake first and then short-press the button to put the car in park? I wouldn't be surprised to hear some motor whine while the car tries to apply the parking brake a second time. Also, if you only short-press the park button, can you then get out and push the car easily?

The first press, be it short or long only puts the car in Park. You have to press again to get the Parking Brake indicator to come on.

 

[Lasairfion]

Determined to find the answer.. Google threw up this gem from forums.tesla.com referring to the Model S:


Roamer@AZ USA | August 16, 2015
I think one is mechanical in operation and the other hydraulic. Hydraulic systems can not reliably hold pressure for long periods.

 

[SpudLime]

The first press, be it short or long only puts the car in Park. You have to press again to get the Parking Brake indicator to come on.

So this indicates that pressing the button to put it in Park is just that. Drive unit is out in a parked state similar to ICE. But if you want the extra protection, hold the park button to turn on the parking brake.

 

[gregincal]

So this indicates that pressing the button to put it in Park is just that. Drive unit is out in a parked state similar to ICE. But if you want the extra protection, hold the park button to turn on the parking brake.

Sigh. Look back at the first post in the thread. The manual is really clear. Putting the car in park engages the parking brake. There is no state similar to a parked state in an ICE. A unpowered electric motor spins freely and would not stop the car from rolling at all.

 

[SpudLime]

Sigh. Look back at the first post in the thread. The manual is really clear. Putting the car in park engages the parking brake. There is no state similar to a parked state in an ICE. A unpowered electric motor spins freely and would not stop the car from rolling at all.

It keeps being said. But what is the difference than holding the parking button and parking brake light illuminates?

 

[TT97]

It keeps being said. But what is the difference than holding the parking button and parking brake light illuminates?

I think someone with a Twitter presence needs to ask Elon. Everyone is just speculating now.

 

[wwu123]

Determined to find the answer.. Google threw up this gem from forums.tesla.com referring to the Model S:


Roamer@AZ USA | August 16, 2015
I think one is mechanical in operation and the other hydraulic. Hydraulic systems can not reliably hold pressure for long periods.

No, don't bring the S into it, it'll just further confuse things. Esp because until early 2017, Model S had TWO rear calipers on each rotor, with one definitely being a separate parking brake. The Mechanical in that quote is likely referring to the separate parking brake, which isn't even in current Model S that use the mainbrake as the parking brake....