Your helpful guide to the Tesla Model 3 parking brake

[SigNC]

if you are having to stop a car moving at 30mph+ that has lost hydraulic brakes AND regen braking you are certainly in a world of hurt

 

[neptunesfinest]

if you are having to stop a car moving at 30mph+ that has lost hydraulic brakes AND regen braking you are certainly in a world of hurt

If it’s cold enough, regen doesn’t even exist so it’s really not a backup to the hydraulic system. I see your point though.

 

[rotus8]

Does hold mode use the parking brake or does it have some other magical way to use the hydraulics?

 

[mongo]

Does hold mode use the parking brake or does it have some other magical way to use the hydraulics?

The electro-hydraulic brake master cylinder, and possibly the drive motors (easier to implement with 3 style)

 

[Seth2020]

Yes
View attachment 526096

If it is absolutely necessary

The electro-hydraulic brake master cylinder, and possibly the drive motors (easier to implement with 3 style)

I heard (and this is not substantiated by any documentation) that HOLD mode is ONLY the electric motors holding the wheels in place - no brakes.

 

[mongo]

If it is absolutely necessary

Yeah, it's not a very controlled application at that point.

I heard (and this is not substantiated by any documentation) that HOLD mode is ONLY the electric motors holding the wheels in place - no brakes.

So, the question is slightly ambiguous since there are two different HOLD modes now: the classic hill HOLD on brake application and the stopping mode (CREEP, ROLL, and HOLD). However they are really same thing and use the brakes.

Stopping mode:

HOLD: Maximizes range and reduces brake wear by continuing to provide regenerative braking at speeds lower than with the Creep and Roll settings. When Model 3 stops, the brakes are automatically applied without you having to put your foot on the brake pedal. Whether stopped on a flat surface or a hill, Vehicle Hold keeps the brake applied, provided your foot remains off the accelerator and brake pedals. See Vehicle Hold on page 72

Vehicle Hold:

When Model 3 is stopped, Vehicle Hold can continue to apply the brakes even after you remove your foot from the brake pedal. When driving on a hill or on a flat surface, brake as you normally would. After coming to a complete stop, simply press the brake pedal again (until the touchscreen displays the Vehicle Hold indicator light) to enable Vehicle Hold. You can then release the brake pedal and remain stopped, even on a hill.
...
Note: When Stopping Mode is set to Hold (see Stopping Mode on page 66), Vehicle Hold engages automatically whenever Model 3stops while in a driving gear. There is no need to press the brake to engage it.

Any car with a 3 style motor could easily do a motor based hold, but that wastes a little bit of energy versus keeping the hydraulics on.

 

[Davidjess]

I will admit, I do find it confusing that the ((P)) icon ONLY appears when you manually apply the parking brake. IMO it should always appear when the parking brake is set.

There are other improvement opportunities that follow the same pattern. For example, navigate on autopilot should be lit up blue only when functioning, outlined in blue when set as default and grey when off and available and white or something when not available.

 

[boildkitty]

This is good stuff. Appreciate all the input. Especially what to do if the brakes have an issue while driving.

 

[conv90]

Yes it's in Italian language, go directly to around 2:30 to see how the car brakes pushing the button. There are many others attempts during the video

 

[ILikeLenexa]

How do we activate the air horn sound at 2:41?

 

[AdamMacDon]

I'm pretty certain the parking brake "feature" is more of a legal requirement and technicality than useful feature. I still use it reflexively on very steep hills when parked, but I know for a fact it uses the same screw style electronic parking brakes on the rear wheels regardless of if you hold it or not. Maybe it holds a bit tighter if you hold the button, but that doesn't make any logical sense. Tesla would obviously want to prevent your car rolling away regardless of method used, so I'm pretty sure the level of force applied is the same. Holding it just reapplies it.

 

[dcdttu]

#1 reason I apply the parking brake? I am trying to push the wiper button and press the wrong one. Talk about panic on the highway, I thought my car was just going to slam itself into Park!

 

[Andy7]

Yes it's in Italian language, go directly to around 2:30 to see how the car brakes pushing the button. There are many others attempts during the video

It seemed like a very quick and uneventful stop-I timed it at about 3-4 seconds from 54 Km/h (probably Km rather than miles). I was impressed considering it is screw action rear braking. I tried translating the captions and it was strange.

I've read the manual and didn't realize about this emergency braking. It is good to know and I will tell my wife, and hope neither of us ever needs it. I might try it to see how it works.

 

[Watts_Up]

Just to add to the fray: Tesla slides down driveway with my kid still inside.

- Would having an additional parking brakes on the front wheels would have been of any help?

Note: I can jump to 0:53 to see the car sliding back and avoiding an other car.

 

[mongo]

- Would having an additional parking brakes on the front wheels would have been of any help?

Sure, but no car has that. Even 4wd or park on a normal car wouldn't really lock an axle since one tire can slip and let the other spin. (Unless it was a Detroit Locker style rear diff.)

 

[AdamMacDon]

Just to add to the fray: Tesla slides down driveway with my kid still inside.

- Would having an additional parking brakes on the front wheels would have been of any help?

Note: I can jump to 0:53 to see the car sliding back and avoiding an other car.

Bad tires and/or parking on a slippery incline surface could cause this problem with almost any car. I can't think of any vehicles that lock the front wheels with the parking brake, it's often a rear drum brake style setup for manual parking brakes, and a rear electronic screw types for electronic ones. Note in this case the cars rear wheels were almost certainly not spinning, hence the problem isn't the brake.

 

[Watts_Up]

Bad tires and/or parking on a slippery incline surface could cause this problem with almost any car.
I can't think of any vehicles that lock the front wheels with the parking brake,
it's often a rear drum brake style setup for manual parking brakes, and a rear electronic screw types for electronic ones.
Note in this case the cars rear wheels were almost certainly not spinning, hence the problem isn't the brake.

This is common sense, so if your driveway is inclined you should turn the front wheels or put a wheel stopper.

Well, in San Francisco you get a ticket if you don't turn your wheels towards the curb on a grade steeper than 3%.
Still many people turn their wheels in the wrong direction..., and also your wheel has to touch the curb.
And some streets are so inclined that you have to park perpendicularly to the road.

 

[mongo]

Still many people turn their wheels in the wrong direction..., and also your wheel has to touch the curb.

I'm curious, do they always turn their wheels the same way, forgetting that uphill should be the opposite of downhill?

 

[Black306]

If there is a curb, you’ll want to turn the wheels in such a way that if the car rolls the wheels will hit the curb and (hopefully) stop the car. If there is no curb, wheels are turned the same way so the car doesn’t roll towards the center of the street.

 

[AdamMacDon]

This is common sense, so if your driveway is inclined you should turn the front wheels or put a wheel stopper.

Well, in San Francisco you get a ticket if you don't turn your wheels towards the curb on a grade steeper than 3%.
Still many people turn their wheels in the wrong direction..., and also your wheel has to touch the curb.
And some streets are so inclined that you have to park perpendicularly to the road.

It should be common sense, but I'd disagree that it is in fact common. Many people seem to have the impression that a parking brake can defeat the laws of gravity and will forever prevent a car from sliding. This is one reason why plowing/salting or sanding your driveway is so important in the winter.