Total braking system failure?

[3silverISgold]

The physical braking system in my Model 3 completely failed this morning.
I didn't realize it until I got on the freeway ramp and almost hit the car in front of me.
Luckily, the regen braking was enough to slow the car down.

The brake pedal felt like it was in a locked position at the top of its range. Could not depress the pedal at all.

This was an absolute critical safety failure.

The car was acting strange from the first moment this morning.
1. erratic window roll down behavior when I opened the front door
2. dark/blank screen upon entry
3. warning message: vehicle hold feature unavailable
4. warning message: 12 v battery must be replace soon

After I rebooted the car, I drove off to working thinking it was nothing.
After realizing the brake failure, I got off the next freeway and exit and drove it back home safely.
With the road side assistance tech on the phone, I tried rebooting the car with no luck.
Then, tried powering the car off via the lcd screen and waiting a couple of minutes seems to solve the issue this time.

The car is now with the Tesla service center.

How could this happen? This was extremely dangerous and I feel very fortunate.
I could have easily found out the hard way at 70+ mph.

Hope this never happens again to me or anybody else, ever.

 

[GoSharks]

I highly doubt it was a "total braking system failure," especially if the pedal was "locked." Sounds like the brake booster failed/was unpowered, but the system is still pressurized and will still work if you really lean into the pedal.

 

[JulienW]

The brakes are a mechanical system with electronic power. Like GoSharks said the power boost goes out you will have to "lean in" to get them to work. Just think a few decades ago most brakes didn't have power so it was a leg "workout" just driving.

 

[3silverISgold]

I definitely leaned in on the pedal, but it wouldn't budge.

 

[kbecks13]

Fun fact - Formula 1 cars don't have power brakes/boosters and it takes about ~300 pounds of force from your leg to properly engage the brakes.

 

[UncertainTimes]

Sounds like a dying->dead 12V battery problem. What year is the car? A lot of 2018s with dying batteries lately. You probably shouldn’t have drove off after the first warning.

 

[GoSharks]

I definitely leaned in on the pedal, but it wouldn't budge.

That's exactly what it would feel like. It is a lot hard than you would expect, nothing like a normal brake feel. IME, you'll need to pull against the steering wheel and/or put your back into it to get the right leverage.

 

[SanteeMike]

I'd go for the brake booster as well. With multiple system failures, I think it's pointing towards the 12V battery.

 

[Phlier]

As others have pointed out, you really have to use all of your leg muscle and a lot of your back strength to manually brake.

My first car was a 1964 Buick Skylark with manual brakes. My right leg was huge by the time I finally parked that car for the last time.

 

[MarsOrBust]

That still should not of happened. If the 12 v battery is going bad they need to find a way to tell us before system failures start occurring. It should give us some lead time. 2 years on the battery does not seem like a long time either.

 

[UncertainTimes]

That still should not of happened. If the 12 v battery is going bad they need to find a way to tell us before system failures start occurring. It should give us some lead time. 2 years on the battery does not seem like a long time either.

12v battery issue, Tesla horrific response

 

[alstoralset]

OP, that's terrifying. One thing I learned after reading your post is that there is a way to trigger the emergency brake.

Hopefully whatever failed in your car does not also take out the ebrake. If so, the lack of redundancy is poor design indeed!

 

[Sophias_dad]

This thread is making me rethink my position on not needing the brake cylinder brace....
MPP Model 3 Brake Master Cylinder Brace | Mountain Pass Performance

 

[AltLogic]

And this is why my insurance rates are too high. One has what they think is total brake system failure and continues to drive home after discovering the problem. Everyone should know the emergency braking procedure before driving a car. Please rename this thread to “Brake pedal seemed to fail” since that is what happened since the operator didn’t attempt to use the emergency braking system.

 

[smatthew]

That still should not of happened. If the 12 v battery is going bad they need to find a way to tell us before system failures start occurring. It should give us some lead time. 2 years on the battery does not seem like a long time either.

This is not related to 12V batteries at all. If the car was awake, the PCS was producing all the 12V the car needs.

 

[Candleflame]

And this is why my insurance rates are too high. One has what they think is total brake system failure and continues to drive home after discovering the problem. Everyone should know the emergency braking procedure before driving a car. Please rename this thread to “Brake pedal seemed to fail” since that is what happened since the operator didn’t attempt to use the emergency braking system.

He didnt even use the normal braking system. The emergency brake system is activated by pressing down on the P button on the stalk which engages the parking brake to slow down.
His brakes were likely completely fine he just needs to press them properly to slow the 2 ton sedan down.

But yeah people like that drive insurance rates up unfortunately.

 

[colinn]

If nothing else, I'm sure a lot of us just learned how to operate the emergency brake

 

[Candleflame]

If nothing else, I'm sure a lot of us just learned how to operate the emergency brake

it is very unlikely, almost impossible that you will ever need to operate the emergency brake.
The foot brake is linked mechanically to the brakes - even if the car is completely incapacitated they should still work, you just have to press harder.

An example would be if someone is not able to move their legs for whatever reason or i.e. if the pedal breaks.

 

[dmurphy]

it is very unlikely, almost impossible that you will ever need to operate the emergency brake.
The foot brake is linked mechanically to the brakes - even if the car is completely incapacitated they should still work, you just have to press harder.

An example would be if someone is not able to move their legs for whatever reason or i.e. if the pedal breaks.

Right. I’ve had “total system failure” before (not in the Tesla) ... power steering and power braking suddenly going away. Alternator seized up and snapped the serpentine belt. It definitely takes some manual effort, that’s for sure. But the systems ARE mechanically connected, so without any power whatsoever, it’s still controllable.

I’ll argue that the Tesla is even better than almost any other system out there, as not only do you have the hydraulic braking, but there’s ALSO regenerative braking available. AND, the electric steering rack has redundant control as well on Model 3.

Sorry this happened @3silverISgold. It’s difficult but manual reversion of the braking system is available. If you’ve never driven without power braking before, it takes a surprisingly large amount of force ... but the hydraulics are all there and working - if they weren’t, your pedal wouldn’t be stiff, it’d be on the floor.

 

[Dangerous Fish]

It wouldn't be a bad idea if every current driver swapped their lovely modern easy-to-drive car with a 1967 stick-shift Mustang for a day. They'd learn a lot about how cars work.