Brake failed and almost crashed

[tstolze]

Why was it suggested to file a complaint with the NHTSA?
Brake failures occur daily on the roads from pinholes in rubber brake lines, rusted or rubbed through metal brake lines, caliper failures, etc.
Get it fixed and move on with life, if something is exposed that seems like it would be a widespread issue, then yes, you might consider the NHTSA report.

Not denying it's a scary situation, just don't think it's worthy of suggesting a report until the cause is uncovered.

 

[junos12]

They just gave me uber credits for 4 days, hopefully it’s not too hard to find the ride getting out from my work at downtown Las Vegas at 11 pm, which is peak hour. Still no report or anything, just waiting.

Here’s the picture of my driveway, I always park with the back side to the garage so I can charge over the night. I have never seen the leak before this incident.

I was rolling and braking few times to test the brake maybe thats why leak is at more than one spot.

 

[junos12]

Why was it suggested to file a complaint with the NHTSA?
Brake failures occur daily on the roads from pinholes in rubber brake lines, rusted or rubbed through metal brake lines, caliper failures, etc.
Get it fixed and move on with life, if something is exposed that seems like it would be a widespread issue, then yes, you might consider the NHTSA report.

Not denying it's a scary situation, just don't think it's worthy of suggesting a report until the cause is uncovered.

I agree, I am waiting to see what diagnosis report says. Thank you

 

[holeydonut]

Why was it suggested to file a complaint with the NHTSA?
Brake failures occur daily on the roads from pinholes in rubber brake lines, rusted or rubbed through metal brake lines, caliper failures, etc.
Get it fixed and move on with life, if something is exposed that seems like it would be a widespread issue, then yes, you might consider the NHTSA report.

Not denying it's a scary situation, just don't think it's worthy of suggesting a report until the cause is uncovered.

Because brake failures of any kind should be filed regardless what the operator believes is the culprit or root cause. Let NHTSA get evidence and investigate if they deem it necessary. Worst possible thing anyone can do is just assume it's no big deal because if everyone assumes it's normal, then there is no body of evidence to analyze. Even moreso for a vehicle as recently manufactured as the OP's.

Even if it is a "pinhole" on a brake line, it doesn't explain why the pinhole causes a failure to the other branch of brake lines not impacted by your pinhole theory.

 

[freeAgent]

They just gave me uber credits for 4 days, hopefully it’s not too hard to find the ride getting out from my work at downtown Las Vegas at 11 pm, which is peak hour. Still no report or anything, just waiting.

Here’s the picture of my driveway, I always park with the back side to the garage so I can charge over the night. I have never seen the leak before this incident.

I was rolling and braking few times to test the brake maybe thats why leak is at more than one spot.

View attachment 685955

Yup, it looks like your car was leaking brake fluid for some reason. Definitely see what the service center has to say about what they could determine about the exact cause of the leak. I assume the Model 3 is using rubber brake lines, but you can also upgrade to stainless steel brake lines if that was the cause and it makes you paranoid.

 

[CorneliusRox]

Does the Model 3 even have the master cylinder and booster along the firewall? Does a Model 3 even have a cross car beam and firewall? lol.

Yeah, it's just under the big plastic cover you see when you open the hood in the typical location you'd expect to see one. The firewall is surprisingly thin and you can see it flex when applying the brakes. I was surprised the first time I witnessed it!

 

[CorneliusRox]

Even if it is a "pinhole" on a brake line, it doesn't explain why the pinhole causes a failure to the other branch of brake lines not impacted by your pinhole theory.

I'd bet the opposite side of the system wasn't compromised. That's just how it feels when you have a failure. I am curious what the root cause is and I hope they share it with OP. I'm guessing they'll just replace parts and not discuss anything though.

A lot of systems are like this where the pressurization of the first chamber pushes on the second, but when that first chamber is compromised (pin-hole leak), there is a physical rod that will push the second cylinder, you just have to push far enough. It's an odd feeling if you don't know what you're looking for.

 

[Alset2]

My bet is blow-by in the master cyl (one of the piston seals fails and the pressure blows by) resulting in diminished brake pedal. It can happen in all cars .
I spent 1st half of my working career as an AISE certified tech .

While this is scary in any car, it does happen to all makes and models. Its a function of hydraulics.

I certainly am not trying to say I know anything about this case, just sharing my years of experience to help put into perceptive. I have had 100s of owners give the description of "pedal went to floor" over the years (becasue that is what it feels like relatively speaking) when in reality I can not think of a case where that was actually the case , except for cases where we know about the failure already

Other have mentioned the dual piston system (x & H references here) and that is correct.
I would bet ,that in fact, the pedal is only going about 1/2 to 2/3s to the floor (the 2nd piston system catches up to the pedal travel) but when its not expected or known about, it feels like to the floor...especially in a panic situation.
I would think that a catastrophic failure where you lose all fluid with one pedal push to be something extreeeeem...like in the movies extreme (see life ins policy comment above...lol).

Anyway, I hope you keep us posted .

PS, I wrote allof this and then saw the pics of the fluid in the drive way, honestly I dont want to waste all my typing because it still applies ,and its a challenge for me to type all of that.
However, this does make me wonder why the car did not give a low brake fluid level warning WAY before a no pedal situation ???

 

[Alset2]

ConrneliusRox...pictures paint a thousand words...perfect!

 

[holeydonut]

I'd bet the opposite side of the system wasn't compromised. That's just how it feels when you have a failure. I am curious what the root cause is and I hope they share it with OP. I'm guessing they'll just replace parts and not discuss anything though.

A lot of systems are like this where the pressurization of the first chamber pushes on the second, but when that first chamber is compromised (pin-hole leak), there is a physical rod that will push the second cylinder, you just have to push far enough. It's an odd feeling if you don't know what you're looking for.
View attachment 685966

Yeah I agree with you and alset2 that most of the time an operator cannot tell the difference between a total and partial brake failure since they don't have much experience to lean on. Plus Teslas have that regenerating braking which helps stop a car even with hydraulic pressure loss. So one would hope junos simply experienced a less efficient braking and not an actual loss of hydraulic wheel braking power at all 4 wheels.

I don't want Junos to share his Teslacam footage... But only he will know if his car basically coasted to a regenerative braking stop... or if he had a hard stop (with that forward/back jolt at the end when brakes-stop-a-car).

 

[KenC]

They just gave me uber credits for 4 days, hopefully it’s not too hard to find the ride getting out from my work at downtown Las Vegas at 11 pm, which is peak hour. Still no report or anything, just waiting.

Here’s the picture of my driveway, I always park with the back side to the garage so I can charge over the night. I have never seen the leak before this incident.

I was rolling and braking few times to test the brake maybe thats why leak is at more than one spot.

View attachment 685955

Not really a whole lot of drops of fluid. Presumably, you lost pressure and fluid while out on the road, and made it back home. These drips are just the remainder as you pumped the pedal.

 

[junos12]

On the following morning while testing, I could push the brake pedal all the way in without much resistance. I don’t know much about cars but it was something I have never felt before in my almost 20 years of driving. When I press the pedal all the way in and let go it made a hissing sound while coming back out. Few times it didn’t even come out right away, took a split second.

 

[pl8dlikafiddle]

Yeah I just forgot this is a Tesla so all the components are hidden behind panels and stuff.

Does the Model 3 even have the master cylinder and booster along the firewall? Does a Model 3 even have a cross car beam and firewall? lol.

Yes. Most convenient place due to brake pedal placement.

 

[CyberGus]

I wanna see the in-cabin camera footage of the OP when he had his "oh sh!t" moment

 

[lolder]

Most if not all cars for decades have had a warning light when one of the two systems fail. It used to be a little free piston open at each end to one of the systems. If one had less pressure the piston moved and a groove around the center aligned with a switch pin and the pin dropped into the groove and gave a warning light that could not be retired until system was repaired. The switch had to be unscrewed and the piston recentered and switch screwed in again. It is extremely unlikely that all braking was lost but due to the farther down pedal travel required it seems that way. When you hold the park button in for emergency braking it is a panic stop with no ABS. Only do it from a few MPH. It's severe.

 

[Dolemite]

Hopefully we get the truth. Wouldn’t be surprised if someone effed something up at the factory.

 

[stopcrazypp]

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...

Here's a video of how to actuate the e-brake while driving for those wondering:

You can see from just a random picture on Ebay of a Model 3 rear caliper there is a black part that is the servo motor that that parking brake actuates. This motor is electrically driven so it'll still work even if you lost all your brake fluid. Obviously due to it being only on the rear brakes and due to how the motor works, it's very slow, so the braking force is very little compared to normal brakes, but it's still better than nothing.

 

[junos12]

I asked if there’s any update on the diagnosis at 3:30 pm but never heard back from them. I will update tomorrow of there’s anything.

 

[booruce]

Crazy experience. Following to see diagnosis and outcome. I have a feeling it’s going to be something dumb like a rodent chewed through something.
Doesn’t explain the failsafes failing though.

 

[Gasaraki]

My bet is blow-by in the master cyl (one of the piston seals fails and the pressure blows by) resulting in diminished brake pedal. It can happen in all cars .
I spent 1st half of my working career as an AISE certified tech .

While this is scary in any car, it does happen to all makes and models. Its a function of hydraulics.

I certainly am not trying to say I know anything about this case, just sharing my years of experience to help put into perceptive. I have had 100s of owners give the description of "pedal went to floor" over the years (becasue that is what it feels like relatively speaking) when in reality I can not think of a case where that was actually the case , except for cases where we know about the failure already

Other have mentioned the dual piston system (x & H references here) and that is correct.
I would bet ,that in fact, the pedal is only going about 1/2 to 2/3s to the floor (the 2nd piston system catches up to the pedal travel) but when its not expected or known about, it feels like to the floor...especially in a panic situation.
I would think that a catastrophic failure where you lose all fluid with one pedal push to be something extreeeeem...like in the movies extreme (see life ins policy comment above...lol).

Anyway, I hope you keep us posted .

PS, I wrote allof this and then saw the pics of the fluid in the drive way, honestly I dont want to waste all my typing because it still applies ,and its a challenge for me to type all of that.
However, this does make me wonder why the car did not give a low brake fluid level warning WAY before a no pedal situation ???

He said the brakes were working then suddenly failed in the middle of a brake application. So the system didn't have a low pressure to detect. Obviously it would then tell you that after it lost the pressure.

Very ballzy for the OP to drive the car with "failed brakes" and only using regen braking. Brakes probably still worked somewhat like you said, maybe the rears still worked.