Wet braking
- Thread starter holabr
- Start date
I drove in the rain for a long time yesterday, and had zero brakes a few times.
Scary a few times as the slowed car up front approaches fast, and you're essentially a torpedo.
To avoid getting killed, I resorted to the age-old technique of braking every few miles to keep the disks "dry" and the brakes working acceptably.
I don't think they're 'broken' at all, but BMW could definitely make some tweaks to make them work better in the rain.
Rotor venting or slotting may help, it certainly can't hurt, it seems.
Scary a few times as the slowed car up front approaches fast, and you're essentially a torpedo.
To avoid getting killed, I resorted to the age-old technique of braking every few miles to keep the disks "dry" and the brakes working acceptably.
I don't think they're 'broken' at all, but BMW could definitely make some tweaks to make them work better in the rain.
Rotor venting or slotting may help, it certainly can't hurt, it seems.
Drilled rotors are not good for much of anything, contrary to popular belief. Slotted rotors will help carry water away, but at the expense of faster pad wear, and slightly reduced dry braking (less surface area). Not much you can do about that part. You could go to longer life pads, but then the rotors will wear faster. All of the choices are a tradeoff of feature/function/cost.
I live in the Seattle area where we get lots of rain, I never have wet brake issues running stock rotors (on the M roadster). I slow down in the rain and brake early. It should only a nano-second for the pads to dry the rotor. I had ATE gas slotted on my 318is and did not notice any improved braking with them either, but did have to replace pads more often. Cross Drilled are for looks with todays brake systems, nothing more.
Not really related but just a comment on the new brakes in new 330i. They have a self drying system. The car senses that it is raining and automaticly apply the brakes very lightly to dry the brakes. I do not notice it when it does this, but I've never had a car that would brake this well in wet weather. Brakes have come a long way. God bless BMW. ![[pray]](/images/smilies/icon_smile_pray.gif "Pray [pray]")
[bmwdance]
[bmwdance]To add, the wet braking problems were noticed during highway driving.
Driving around town, they've always been fine.
But I was driving at 60MPH for 30 minutes in continuous rain, and when I went to hit the brakes for a car slowing (he was nearly stopped) there was nothing for about 4-5 seconds.
That will get your attention in a hurry. Luckily I wasn't following close behind, or I would have smacked into him at 50MPH.
Those 4-5 seconds of dead brakes at 60MPH translates into a few hundred feet. Fortunately, the brakes finally burned off the water, and I was able to slow down with about 20 feet to spare.
While highway driving in the rain, keep lots of room betwen the car in front, and hit the brakes often to keep them working.
Driving around town, they've always been fine.
But I was driving at 60MPH for 30 minutes in continuous rain, and when I went to hit the brakes for a car slowing (he was nearly stopped) there was nothing for about 4-5 seconds.
That will get your attention in a hurry. Luckily I wasn't following close behind, or I would have smacked into him at 50MPH.
Those 4-5 seconds of dead brakes at 60MPH translates into a few hundred feet. Fortunately, the brakes finally burned off the water, and I was able to slow down with about 20 feet to spare.
While highway driving in the rain, keep lots of room betwen the car in front, and hit the brakes often to keep them working.
Ok let me say this...i live in Germany.....the average highway speed is almost 2x of what you quoted up top...and in the rain it is probably around the 75-85mph range....not mention my car is older AND heavier than both of your cars...and i have NEVER and I repeat never experienced this phenomenon.....strange dont you think?
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I concur, 4-5 seconds is way too long, it should take no more than a second, at the most to dry the rotors! You need to have your brake system inspected. I can drive to my daughters home 1 hr and 15 min best time, in a continual down pour and never have experienced any loss of brakes due to rain. Not in the roadster, the 318is or the 750iL.
That "self drying feature" would be a pain here in our rain, you'd feel the brakes applied every few seconds and buy pads every other month!
That "self drying feature" would be a pain here in our rain, you'd feel the brakes applied every few seconds and buy pads every other month!
![[thumb]](/images/smilies/icon_smile_thumb.gif "Thumbs Up [thumb]"){kind=icon}
your brakes are wet.
dude, your brakes were wet. You can't have nothing from a hydraulic pressure system, even if the booster fails you are appling brakes immediately. You should lightly drag your brakes in the rain from time to time. Get your car inspected immediately with a test drive in the rain with a mechanic otherwise.
dude, your brakes were wet. You can't have nothing from a hydraulic pressure system, even if the booster fails you are appling brakes immediately. You should lightly drag your brakes in the rain from time to time. Get your car inspected immediately with a test drive in the rain with a mechanic otherwise.
4-5 seconds? i think your feeling tricks your mind here. 4-5 seconds would result in more than just attention. you would panic by then. not even thinking about the braking you would have to do to catch up for the lost 4-5 seconds. I think you are thinking it was that long, but it wasn´t.
if i am mistaken here and you had the stop watch prove your ground, you better look out for a dealer to check the problem. if not, you might wanna get used to a little delay in response when it rains. that is normal. but it is indeed very little.
the proposal to keep your brakes dry by using them from time to time is quite usefull.
if i am mistaken here and you had the stop watch prove your ground, you better look out for a dealer to check the problem. if not, you might wanna get used to a little delay in response when it rains. that is normal. but it is indeed very little.
the proposal to keep your brakes dry by using them from time to time is quite usefull.