Reduced braking after car wash

[DJ_S75D]

I just wanted to contribute by saying that I've definitely experienced the reduced braking after washing my car.

There is a hill at the entrance / exit to my local DIY carwash place and I've nearly rolled right into the street below on a few occasions while stopping. Perhaps it's residual soap on the brake pads? Or maybe it's just the presence of water? My brakes usually perform the same in rainy conditions as they do on a sunny day, so I'm leaning to the presence of soap and other chemicals really changing the stopping power after washing the car. I don't think it's a flaw, and it would probably show up on any car with similar pads and rotors.

-DJ

 

[mongo]

I just wanted to contribute by saying that I've definitely experienced the reduced braking after washing my car.

There is a hill at the entrance / exit to my local DIY carwash place and I've nearly rolled right into the street below on a few occasions while stopping. Perhaps it's residual soap on the brake pads? Or maybe it's just the presence of water? My brakes usually perform the same in rainy conditions as they do on a sunny day, so I'm leaning to the presence of soap and other chemicals really changing the stopping power after washing the car. I don't think it's a flaw, and it would probably show up on any car with similar pads and rotors.

-DJ

There is also the drying effect due to wheel spin that you get when driving in rain v.s. creeping out of a car wash.

Edit: Along with the direction water impacts the brakes. Normally, the tire shields most of the spray, but a car wash shoots the water sideways onto the pads/ rotors.

 

[Naonak]

I see the OP and others are still trying to pump the brakes. You shouldn't pump ABS brakes. You should push the brake pedal as firmly as possible and let the ABS do its job. The pulsing you feel when applying the brakes means the ABS is doing its job. ABS is able to cycle the brakes much faster than you can with your foot, with some systems able to cycle the brakes 16 times per second.

The ABS doesn't work when the pads are wet. It sees the wheels still turning, so ABS never kicks in... but since the pads can't get a bite in to the rotors due to surface tension of the water, you have reduced (or no) braking. ABS is not a factor and the only way to fix it is to either stay hard on the brakes and hope the water evaporates, or pump the brakes to give the water time to clear.

 

[Graffi]

What I have Learned about Winter/Snow Tires from this Forum:

Firstly, I grew up in South Georgia, so rarely got below freezing, although we did have Freezing Rain but snow only once every 5 to 10 years, but gone by noon. I did not experience needing to have two sets of tires. Now living in San Diego same thing, unless we travel to the cold country.

What I have learned is that for those living in places that stay cold most of the winter, maybe middle of USA on up, or those living in high altitude, there is the need for two sets of tires, not just for snow, but for the colder temps. Not sure what temp, but I am sure someone here knows. Lets say below 50*f. It is about the softness of the rubber on the tire, not snow or ice.

If I were living in the colder climates I think I would use Thanksgiving and Easter as the targets. Sometime before Thanksgiving when the day time temps are in the 50's I would change to Winter tires. Sometime around Easter when the day time temps stay above 60's I would change back to Summer Tires.

For those in the know, what would you change in the above? Inquiring minds want to know.

 

[DFibRL8R]

This is a good point. When the S has traction problems, if feels a lot more like my Ram 2500 than my old BMW 330. But when driving in good road conditions it certainly feels much more nimble due to the power delivery of the electric motors.

+1 to this. The Model S is a very heavy car but in normal conditions it's weight is not that apparent due to power of drive motor(s) and power of regen braking. As a good example, it is always surprising to me when the S battery is truly cold and there is no regen at all how much harder it is to brake with only the friction brakes. I often find myself miscalculating and coasting a bit farther than I intend in this condition. When any of the terrific systems are limited due to road conditions or other factors (like no regen in cold) it can introduce an unwelcome element of change to an experienced Model S driver. This is why I hedge my bets and switch to winter tires every November-March even though I am in VA.

Also, I have too experienced the phenomenon of water-logged brakes when driving in rain due to build up of water on the pads. It's also a bit unnerving if you have to make a sudden stop.

 

[MorrisonHiker]

What I have learned is that for those living in places that stay cold most of the winter, maybe middle of USA on up, or those living in high altitude, there is the need for two sets of tires, not just for snow, but for the colder temps. Not sure what temp, but I am sure someone here knows. Lets say below 50*f. It is about the softness of the rubber on the tire, not snow or ice.

If I were living in the colder climates I think I would use Thanksgiving and Easter as the targets. Sometime before Thanksgiving when the day time temps are in the 50's I would change to Winter tires. Sometime around Easter when the day time temps stay above 60's I would change back to Summer Tires.

For those in the know, what would you change in the above? Inquiring minds want to know.

When I lived in Montreal, there were distinct seasons and it would be easy to follow your guidelines because once it started snowing, the snow would be on the ground for 6+ months. Living in Colorado, we can experience all seasons in a couple days or even in the same day. Last week, it was in the 60s every day. This past Sunday, it was in the 70s. On Monday, we got about 8" of snow and then it got down to below 0 F and I believe it's been below freezing ever since. I can remember one time when I was out hiking in shorts and sandals. I went out to dinner with a friend and a cold front came in. We had about 3 inches of snow in an hour...and I was still in shorts and sandals.

Anyhow, I don't know of (m)any people who regularly switch their tires out in Colorado. I'm sure some people do it but not the vast majority.

 

[ChrML]

I drove home in the same weather today as you (took me over an hour for a 20 minute commute because of all the accidents). You slid on snow and ice. My wife said a vehicle nearly slid into her when she was driving today. There was freezing rain and snow that hit frozen streets. It may have felt like you had no brakes but your tires were not moving and your brakes were working fine. You were sliding.

Well, I have experienced the same. Inside a parking house down a steep floor climbing hill (probably 10%), on dry asphalt. Happened on first drive after parked after driving in similar conditions as OP. The brakes started working just before I hit the wall.

It's not the tyres slipping. Some situations cause 0 friction between brake pads for several seconds with max force. It's due to roadsalt layer. Now I always brake my brakes warm before parking.

 

[bigbill]

Ice in the brake lines can freeze, causing the pedal to be hard with no braking. Get your brakes flushed regularly.

 

[Dakkor]

I have my car since 2 years and a half and this happened to me for the first time this year. Multiple time. Even in a parking garage I stopped at about 1 cm from the concrete wall. It always happened on the first brake I did of my driving when it happened.

 

[NCAviator]

Dear OP;
What is the status of the vehicle now? I assume you are not driving it after your accident and no breaks. Has the vehicle been inspected? Was the problem brakes or conditions? You are also free to notify the NHTSA. See here: File a Vehicle Safety Complaint | Safercar.gov | NHTSA

 

[Canuck]

You are also free to notify the NHTSA.

I guess if he wants to waste time and taxpayers' dollars he can do that but it would be Transport Canada in his case. They will investigate and find the brakes are working just fine. If we could legally bet here, I would even give 100:1 odds to all the naysayers.

 

[Evil Twin]

I grew up in Canada....you had brakes....gravity and inertia were your enemies that day.

 

[Evil Twin]

....and their good buddy, friction coefficient

 

[Asymmetry]

I've read in the forum of cars having little to no brakes after washing/really wet. .

Was this a post on a Honda forum?

you live in Canada, arent you aware of black ice?

 

[ElectricTundra]

I've experienced no brakes a few times in winter when leaving a car wash. A few days ago it happened and I was on dry pavement so definitely not sliding on ice. A bit unnerving to say the least. Usually clears up quickly though. I've also experienced it a couple of times backing out of my garage (dry sloped driveway).

Softer winter tyres are great but if you put them on @ 50°f they won't last very long. We generally don't switch until average highs are below zero (MN) so usually late Nov till early Mar. All weather's have gotten quite good though so about half the folks I know will no longer switch to winter tyres.

 

[Canuck]

Softer winter tyres are great but if you put them on @ 50°f they won't last very long.

Yes -- I know that well. But the alternative is don't use them and when a cold spell comes along you might not last very long (or worse, someone you hit) -- instead of your tires. So it's not a good alternative to avoid them to save costs, at least in my view.

 

[mattack4000]

If it is that easy for water to prevent the brakes from working, I guess we should never drive in the rain. This is an ev car, it doesn’t have track pads...

 

[daktari]

Lots ut "failed brakes" reports in Norway also, early cars are retrofitted. Had it myself one day, felt as if the brake amplifier did not work.

This case seems more like traction. See the picture of my neighbours S after it slid sideways while parking this was on winter tires. Sometimes snow is really slippery!

 

[David.85D]

You had brakes but the road was ice so when you pressed on the brake it felt like nothing happened. If you really had nothing, your foot would have hit the floor. That would have meant the brake lines were dry. They were not. You had brakes.

I've been here for 4 years and there's no reports of no brakes after washing vehicles. In fact, the opposite is true. The brakes stick due to rust but that's a different issue.

Trust me -- you slid on ice. You probably don't even have snow tires on the vehicle -- right?

I think you are taking aim at the choice of words and not hearing the message. I certainly have had the “wet brake effect” where the pedal is still firm, but produces no noticeable stopping power. It happens to me at startup after a car wash or rain even in warmer weather. It doesn’t require ice. Doesn’t matter if I have summer or snow tires on. I think it is the particular brake pad Tesla uses is very ineffective when both cold and wet.

I’ve gotten use to pumping the brakes leaving my driveway to dry and warm them a little.

Problem is probably made worse in very cold weather since regen braking will not be available.

 

[David.85D]

What I have Learned about Winter/Snow Tires from this Forum:

Firstly, I grew up in South Georgia, so rarely got below freezing, although we did have Freezing Rain but snow only once every 5 to 10 years, but gone by noon. I did not experience needing to have two sets of tires. Now living in San Diego same thing, unless we travel to the cold country.

What I have learned is that for those living in places that stay cold most of the winter, maybe middle of USA on up, or those living in high altitude, there is the need for two sets of tires, not just for snow, but for the colder temps. Not sure what temp, but I am sure someone here knows. Lets say below 50*f. It is about the softness of the rubber on the tire, not snow or ice.

If I were living in the colder climates I think I would use Thanksgiving and Easter as the targets. Sometime before Thanksgiving when the day time temps are in the 50's I would change to Winter tires. Sometime around Easter when the day time temps stay above 60's I would change back to Summer Tires.

For those in the know, what would you change in the above? Inquiring minds want to know.

This is pretty much my plan, too. I run snows from roughly Dec 1 to the end of March. Will put them on early if we are expecting early freeze or snow. They are softer in cold weather, and wear very quickly if you leave them on when it gets hot. If you follow a schedule like this, 4 winters from a set of tires is not hard to achieve. $250 a year is well worth it to me.