icy rain driving - The Unofficial BMW M5 Messageboard (m5board.com)

tfung · 19th November 2002, 01:24

Don't think anyone has mentioned it before, but I guess it could also be common knowledge.. since I'm from Hong Kong and very seldom drive in conditions like I did today, I thought I would share in case other people didn't know...

was driving back from Toronto to Boston today, and the conditions were pretty bad today... icy rain mixed with snow, etc... While driving on the highway, I noticed that after driving about an hour or so without using the brakes at all, when I needed the brakes all of a sudden and stepped on the brake pedal, the brakes don't bite at all! It takes roughly 2 seconds before it grips... I don't know what happens, but I presume that the water sort of freezes on the brake pads and it takes longer than usual for it to grip because of the ice? so after a few times like that today, I learned to use the brakes once in a while so that in case of a real emergency, the brakes won't hesitate to grab... :p

19th November 2002, 01:32

Tfung, I've heard about the Ice/snow storms hitting some parts of the East Coast....Good Job you came back in one piece!

Doesn't Mercedes's Electronic Brakes Feather the Discs when it's raining, automatically?

BoringFamilySedan · 19th November 2002, 01:32

yeah.......the weather is terrible here so we couldn't even meet up!!!

we have the same brake problem as u mentioned after auto car wash @ gas station coz the blow dryer doesn't make the water on our brake disks goes away. so mostly we have to keep braking till we actually feel the brake is working properly.

chunpng · 19th November 2002, 02:11

I've also read somewhere that driving in low temp. conditions, one should brake gently, intermittently to keep the brakes warm.

No practice here in the Bay Area though. 72 degrees out with featherly clouds. We have such rough weather here.

Keep safe.

CP

Rezf · 19th November 2002, 04:59

Terence,
What you expereinced is not a "cold" weather/icy rain phenomenon, but rather due to rain (water) building up around the brake pads, like a film. In wet conditions, you should periodically hit your brakes, in order to keep them "dry" so they have the intended efficiency. I have expereinced what you described in the middle of July during a rain storm

TCM · 19th November 2002, 04:59

Glad to see you made it back in one piece Terence. I would have thought the roads would have been half way decent but I guess not. As far as the braking in the rain, you are supposed to apply your brakes every so often in wet conditions, I beleive it states that in the manual. The water build up on the rotors decreases brake performance so by applying the brakes every so often you clear the rortor surface so you can have consistent brake performance when needed as the pad makes direct contact with the rotor. You will also see pro racers always tap the brakes on long straights when it rains to make sure they have good braking capabilities for the end of the straight.

chazzy · 19th November 2002, 09:45

On the new E-Class (and the SL, I think), the Sensotronic Brake Control touches the brake pads to the rotor periodically when the wipers are going to keep the pads and rotor dry. Neat feature that will show up in other cars, for sure.

ycchan · 19th November 2002, 10:46

tfung,

were you driving with snow tires?

Kurt555gs · 19th November 2002, 11:08

When I bought the M5 I figured that I would just drive it on summer evenings and weekends .... well the problem is ... well I just love driving the thing and I keep making excuses to just go some where. I got it brand new in April this year and it is approaching 20K miles.

So last weekend , the fam wanted to go to the weekend house in Fennville Mi (about 2.5 hours from Joliet) ...... but I suggested it would be fun to take a "ride around the pond" ... so ... the fam aka wife and teenage creature daughhter thought .. oh well he is crazy but sometimes fun ... so .... lets go.

Ok so instead of heading to Michigan we went north , through Duluth Mn ... then up to Thunder Bay On.

Well ... I wanted to stay in Thunder Bay .. but wifey and Teenage creature daughter said ... it's only 4:00 PM .. lets keep going .... I explained that I had done this trip many times before and there isnt much heading east .... they insisted however so ... off tword Nippigon we went.

Then it started to sleet , and the fog rolled in at the same time ...

Since the M5 doesnt have de-icing boots on it's leading edges .. lol i noticed that ice was building on the mirror shrouds , and everywhere else ... like the road.

Any one who has ever taken 11/17 around the north shore of Superior can appreciate this, but it is had to put to words the excitement that driving on twisty, mountainous roads on glare ice at night in the fog can bring.

well .. the outcome ..... DSC works, although it was lit up like what you would normally see of worning lights on mid 70's ghetto cruisers, I didnt slide off into the canadian wildness.

We got to Nippigon, and found a motel ... I can sleep in a hallway, but my wifey & teenage creature daughter found the accomidations lacking .. lol

Only place that had rooms was .. well ... one of those places no one ever admits to being in .. but one would imagine ending up there with a lady that has .. well .... lets say a very low TOOTH / TATOO ratio ....

Anyway ..... rest of the trip was fun except that Canadians seem to like to obey speed limits (90 kp/h) when there doesnt apear to be the need to ........... and US Customs was a pain comming back through at Ste Sault Marie MI .....

Oh well .. the M5 is no worse for the experince except for the now custom grips in the steering wheel and the vertical crease in the seat cushin

cheers

SUPRA · 19th November 2002, 12:02

Certainly fun, but I don't think this is the perfect conditions for the M5...