Brake failed and almost crashed

[junos12]

So I owned my model 3 for about a year, never really had any problems until yesterday, and then I had a very serious problem.

I was driving at about 40 mph and this car in front of me stopped at green light for whatever reason, forcing me to hard brake, in the middle of braking, all of a sudden I felt no resistance with the brake pad and my car just failed braking. I had to swerve my car around in order to avoid crash, almost hitting the traffic divider. I somehow managed to avoid the crash and nobody got hurt although me and my wife both were so surprised that we are having cramps all over the body. It was after business hour for the Tesla dealership so I had to call the service and they towed my car.

After this incident, when I press on the brake pad it just goes in all the way braking just a little bit and when I let go, it gets released with hissing sound. Few hours later my screen says "Brake fluid Low Pull over safely."

That was such a scary experience, glad it didn't happen on the freeway at higher speed. My wife is scared to ride this car anymore... has this brake failure ever happened to anybody?
Gonna have to wait until tomorrow to hear back from the Tesla dealership as they don't open on Sundays in Las Vegas.

 

[Rice&Curry]

I am glad everyone is safe...please reach out to Tesla immediately ... this is a safety issue and please do not drive the car until you talk with Tesla on the next steps.

 

[holeydonut]

Hmm I don’t think this is a failure of the brake booster master cylinder or the backup hydraulic compensator… usually when those go bad your brake pedal gets really stiff… your problem is the pedal goes all the way through without resistance.

I wonder if somehow you blew through your brake bleeder screws? But usually brake systems are on a X pattern (not sure about a Model 3) … so losing one pair of brakes should leave you with pressure on the other pair. 4 wheel brake failures are super uncommon in vehicles with all this redundancy.

 

[junos12]

I am glad everyone is safe...please reach out to Tesla immediately ... this is a safety issue and please do not drive the car until you talk with Tesla on the next steps.

Thank you they towed my car, I am not driving that car until everything is thoroughly checked.

 

[junos12]

Hmm I don’t think this is a failure of the brake booster master cylinder or the backup hydraulic compensator… usually when those go bad your brake pedal gets really stiff… your problem is the pedal goes all the way through without resistance.

I wonder if somehow you blew through your brake bleeder screws? But usually brake systems are on a X pattern (not sure about a Model 3) … so losing one pair of brakes should leave you with pressure on the other pair. 4 wheel brake failures are super uncommon in vehicles with all this redundancy.

I rarely used the brake as I prefer regenerative braking. I don’t know how it can get messed up after one year of minimal use..

 

[techzelle]

Emergency brake = press and hold park button.

Low on brake fluid? I wonder how that happened... let us know when you find out.

 

[LoudMusic]

Emergency brake = press and hold park button.

Low on brake fluid? I wonder how that happened... let us know when you find out.

What happens if you shift to park or e-park while rolling?

 

[junos12]

Emergency brake = press and hold park button.

Low on brake fluid? I wonder how that happened... let us know when you find out.

Will do

 

[junos12]

What happens if you shift to park or e-park while rolling?

It does stop completely.

 

[P3dStealth]

What happens if you shift to park or e-park while rolling?

The parking brake is electro mechanical. It's also the emergency brake if you hold park it will engage while driving. If you just tap park while driving it does nothing.

They should really label the emergency brake or something. I discovered it by mistake myself. I accidentally held down park instead of the washer fluid button.

 

[Rmchrger]

So glad everyone is ok. Scary moment for sure. Ya please let us know what the outcome is. I'm now tempted to experiment with the ebrake and park so I'm aware of what I can do in a similar situation happens. Sorry I haven't searched yet, but has anyone else done the ebrake and park attempt and knows what happens? Good spot to insert a link or video as reference.

Haha, thanks P3Dstealth and junos12 you beat me...

 

[sodakar]

Glad you’re safe. I’m assuming the regen brakes helped you slow down and eventually stop?

Sounds like you somehow lost most of your brake fluid. Fictional TV shows usually attribute this to road debris damaging your brake line, but not sure how realistic that scenarios is.

Curious as to what really happened. Thanks for the heads-up on the Park/emergency brake.

 

[P3dStealth]

So glad everyone is ok. Scary moment for sure. Ya please let us know what the outcome is. I'm now tempted to experiment with the ebrake and park so I'm aware of what I can do in a similar situation happens. Sorry I haven't searched yet, but has anyone else done the ebrake and park attempt and knows what happens? Good spot to insert a link or video as reference.

Haha, thanks P3Dstealth and junos12 you beat me...

If you hold park it just beeps and says emergency brake applied on the screen. I let go so not really sure how hard it would apply.

 

[Sam1]

I'm now tempted to experiment with the ebrake and park so I'm aware of what I can do in a similar situation happens. Sorry I haven't searched yet, but has anyone else done the ebrake and park attempt and knows what happens? Good spot to insert a link or video as reference.

Haha, thanks P3Dstealth and junos12 you beat me...

You should have done that when you got the car. This isn't directed specifically at you, but it is mind-boggling how many people do not even know how to use the safety features of their cars, much less, tests them.

 

[CorneliusRox]

It sounds like a brake line failure to me. Typically when they break, it's a 'pin-hole' break and you'll hear that hissing. The pressure you generate with the brake booster and the brake master cylinder leaks out of the hole instead of actuating the brake caliper pistons.

I've had this happen on old rusty vehicles before (at least three times, I was very broke in college! ha ha). It's scary, but easily fixed.
This is why brake master cylinders are separated into a front and rear partition. If you lose the front, you'll still have the rear and vice versa. It's possibly you lost the front that's ~70% of your stopping power and the rears weren't doing much of anything.

Either way, I recommend giving your brakes a really good stomp every once in a while to check for this. I'd rather my brakes go out when I'm close to home and on a road nobody else is on, than when I actually need them!

Glad you're safe OP. Please report back with your findings!

 

[Tom_rob]

Has your wife recently increased your life insurance policy? Just curious….
Glad you’re safe!

 

[holeydonut]

It sounds like a brake line failure to me. Typically when they break, it's a 'pin-hole' break and you'll hear that hissing. The pressure you generate with the brake booster and the brake master cylinder leaks out of the hole instead of actuating the brake caliper pistons.

I've had this happen on old rusty vehicles before (at least three times, I was very broke in college! ha ha). It's scary, but easily fixed.
This is why brake master cylinders are separated into a front and rear partition. If you lose the front, you'll still have the rear and vice versa. It's possibly you lost the front that's ~70% of your stopping power and the rears weren't doing much of anything.

Either way, I recommend giving your brakes a really good stomp every once in a while to check for this. I'd rather my brakes go out when I'm close to home and on a road nobody else is on, than when I actually need them!

Glad you're safe OP. Please report back with your findings!

Yeah, but that's why master brake cylinders are typically in a X or H configuration... so a pin-hole type of issue only takes out the brakes on two wheels.

For a complete brake failure where all pressure was lost, the master cylinder would have to have a slow leak somewhere that depressurized the whole system. But there are usually a couple sensors on the fluid/pressure level to alert the driver if the system is compromised before the driver pushes the pedal to find nothing is there.

Most of the time the severe brake problem that folks experience is where the system loses power-assist, and the pedal becomes very firm. The operator basically has to stand on the pedal to get braking action. That is why in-motion vehicle stalling events are so dangerous... since the driver would only have 1 or 2 stomps on the pedal before the hydraulic system loses power. I believe Tesla Model 3s even have a backup hydraulic compensator to put some pressure into the brake lines when the main system fails.

I'm very interested in learning how Junos12's car somehow had the worst possible outcome in spite of the many fail-safes in place. What he experienced is worse than a stall since at least with a stall you still have some brake assist. It's great that he's ok, and a serious collision was avoided. He definitely needs to make sure a NHTSA complaint is documented against this issue.

 

[jjrandorin]

(personal comments only, NOT moderation comments, representing TMC, or anyone but myself, jjrandorin the regular poster)

Due to my time here on TMC, and various discussions around topics like "unintended acceleration" and also braking like this, I am always skeptical of posts like this especially when (like this poster) they joined TMC basically to make this post (OP is a TMC member since "jul 18th" showing right under their name, not through any moderator portals or anything).

I am also not a person who specifically thinks everything is either "FUD", "shortesllers" or "fanbois", but as I said, I get very skeptical around topics like this, where some catastrophic set of circumstances combine to make something happen where there are multiple systems in place to prevent exactly that thing from happening.

Not that OP needs to prove anything to me, or anyone, but for me, I would want to see a copy of the tesla service center paperwork (with appropriate personal information blacked out) showing that the car was actually in service and " customer states complete brake failure" or something, on a tesla service center submittal, to prove that the OP actually took the car to service, AND that was the specific complaint.

Failing that, I remain skeptical. Like I said, everyone is free to choose what to believe, etc, and I am almost sorry that circumstances make it so I cant "automatically trust" what people say online, but, here we are.

==================================
(moderator note)

Since there may be new people coming to the thread and reading along, I am editing my post here a bit to let people know that the OP of this thread posted a screen shot of the beginning of their conversation with the SC, showing the car was indeed in service.

This post can be found in post#34 in this thread which i will link to in this post. Even though I was clear to post my skepticism as a regular poster and not as a moderator, I still feel its the "right thing to do" to edit this post so that people reading know "sooner" that proof was provided.

Brake failed and almost crashed

If the service department confirms that it was an actual brake failure and not a user error, please consider reporting the issue to NHTSA at safercar.gov. I agree a valid complaint should be filed with NHTSA if there was a brake failure. But I disagree that “operator error” events should...

teslamotorsclub.com

 

[mtndrew1]

If the service department confirms that it was an actual brake failure and not a user error, please consider reporting the issue to NHTSA at safercar.gov.

 

[medphys3]

"After this incident, when I press on the brake pad it just goes in all the way braking just a little bit and when I let go, it gets released with hissing sound. Few hours later my screen says "Brake fluid Low Pull over safely."

This is an interesting statement.

Did it take three hours to have your car towed?
Did you drive around after the brake failure?
Did that warning occur earlier and you ignored it?

I know sometimes things get lost in translation, but this just reads oddly.