Braking in rain

[Andyw2100]

I have an S70D and recently after driving for 2 hours in heavy rain my brakes failed to work twice within a period of 4mins after i got off the highway. Thank god the roads were empty. Tesla service checked the brakes and did not find anything abnormal. I am thinking due to regenerative braking i am not using the brakes enough and this somehow has an adverse affect in severly wet conditions. It does however worry me that I have no control when this could happen again.

As I understand it, the reason this happens is that ordinarily,in cars without regenerative braking, the brakes would be hot, and water would evaporate quickly off them. So you are correct that what you experienced is related to regenerative braking, in that your brakes were not hot because you had not used them.

The thing is, you do have control over this situation. When you are driving in wet conditions, just test your brakes from time to time, and certainly, as you are, say, getting off the highway, begin braking before you really need to start braking. In other words, awareness of the issue can really handle 90% of it.

Good luck!

 

[hpartsch]

Well, I guess I can add my unfortunate experience to this thread...

In the past I did note on occasion reduced braking performance (after touchless car wash, driving in heavy snow), but it was always limited to uncommon situations.

On january 1st after an hour-long highway drive in wet conditions, following the flow of traffic using cruise / regen, I got into town on a busier highway and the vehicles ahead of me slowed.

Pressing the brake pedal did very little, and I wound up rear-ending the car in front of me, a very similar outcome to what PeterK had described earlier in this thread. I must have hit at less than 30 km / h, no airbags deployed, and no one was injured.

Since I was braking the hood and upper half of the nosecone took the brunt of the impact. I now have a frunk full of winter clothes (and my UMC) that I cannot open, and am seriously pissed off at the start of my new year... :crying:

I was able by pure luck to reach the manager of the Montreal Tesla store who was there filling paperwork (everything garage-related is closed here until next week), and he lent me a UMC to charge my car at home.

If this is a known issue with early VINs (I am in that group), I am not amused. It is at the very least a serious security concern, the outcome could have been dramatic at highway speeds.

I almost had the exact same thing happen to me during heavy rain. Tesla has ordered the new parts and their eta is not known at this point. I'm a bit suprised that this wasn't proactively updated as it is clearly a safety concern (my car is a 2013). Did this fix the pulling to the side when braking moderate to hard? I've literally had the car pull into a different lane. No sign of abs or stability control activating. Only occurring during rain.

 

[Jeeps17]

I almost had the exact same thing happen to me during heavy rain. Tesla has ordered the new parts and their eta is not known at this point. I'm a bit suprised that this wasn't proactively updated as it is clearly a safety concern (my car is a 2013). Did this fix the pulling to the side when braking moderate to hard? I've literally had the car pull into a different lane. No sign of abs or stability control activating. Only occurring during rain.

I cannot say I've had issues with the car veering when braking.

 

[hpartsch]

Humm interesting and good to know. This has happened each time I have been on the highway and the braking hasn't worked properly. I guess I will wait to see if the new brakes/pad fix this issue first. In reading the posts, I didn't really see the pulling/veering issue being mentioned -- but everything else is exactly what I'm experiencing.

I cannot say I've had issues with the car veering when braking.

 

[hpartsch]

Had my brakes and rotors replaced today by Tesla Mobile Service @ my work parking lot. It was very nice to not have to drive 3+ hours in one day to Bellevue and then again do the same trip the next day (especially in rainy weather with this problem). I asked about an update to the braking firmware and he looked into it. It is being installed right now remotely. Hopefully these fixes, fix the issue!

 

[PaulS]

I have experienced the exact same thing 3 times in rainy/slushy weather this week. 1 of the 3 times I sailed through a stop sign because of it (only going 30 km/h and the car wouldn't stop). And I turned Regen Braking to Low and it happened again. Seriously concerning. This is our first issue that really is shaking our confidence in Tesla.

 

[hpartsch]

I have experienced the exact same thing 3 times in rainy/slushy weather this week. 1 of the 3 times I sailed through a stop sign because of it (only going 30 km/h and the car wouldn't stop). And I turned Regen Braking to Low and it happened again. Seriously concerning. This is our first issue that really is shaking our confidence in Tesla.

I would contact Tesla Service -- they will make it right. I'm assuming you have an early model Model S?