DocFreud

hi there,

i've experienced some problems, when its raining and i am driving over 60mph the brakes are really delayed. it is most noticable when i press the brake pedal lightly, then for nearly a second nothing happens until the brakes get a grip and the car pushes to the right..

anyone knows what could cause this? the alignment was done a short time ago, and the brake fluid was renewed.
i have the bigger is 350 brakes on my 250. stoptech rotors and pads.

other mods are kw v3 coilovers, 2 degree camber on front and rear, sway bar in the front.

Aspect

Have you checked the condition of your tires and pads? The slow response in braking with light pressure applied could be due to worn down pads. If your car is pulling to the right during braking, I suspect it might be a grip issue with one tire being worn more than the other or that your braking force is possibly being biased on one side.

Gville350

iTrader: (10)

If you're getting a push/pull under braking, then I'd check out your braking components for uneven wear patterns.

DocFreud

thanks for your advice. the tires are 4 month old and have no significant wear patterns. the brake discs and pads are also okay. just checked them today.
i've noticed that in the middle of the pads is a groove, that was filled with brake dust. cleaned it now.. maybe that helps.

scott1256c

What is the behavior when it isn't raining? Brakes are responsive? Car pull to the left or right when you start braking and it is dry? How does the car track if you aren't braking? Pull right or left? Straight?
Brake fluid was replaced a short time ago? Doesn't sound like an air bubble, but can't hurt to bleed them a little and see.

If it is only a "rain" thing, then you'd think something was sticking, but nothing is coming to mind that would cause the car to not brake under light pressure when raining, but be responsive when dry.
Can you tell if it is affecting both front and rear? I'd suspect it might have something to do with the seal on the rear caliper pin. Can you remove the rear wheels and see if the rear calipers are sticking or move side to side easily?

DocFreud

when it is not raining, the brakes are fine, really responsive. no pull to the left or right. there is also no pull while driving.
i've googled the problem, found a lot reports from audi drivers with the same problem.

maybe you are right, i should check the rear brakes. allthough they are quite new, i've renewes discs and pads last year, everything was moving.

if i brake hard while it is raining, there is also a delayed response, but not that much and after the brakes respond the car pulls to the right..

scott1256c

I wish I could offer more assistance. Sorry, I don't know what else to suggest.

strikeraj

have you tried bedding the brakes again?
just a thing you can try easily

SeanO

iTrader: (1)

This ^ -- sounds like there could still be air in the system..

I recently had my brakes serviced and the quality tech at Lexus said they had to bleed them 3 times

As mentioned the pulling will be caused by uneven wear of possibly seized caliper

DocFreud

if there is air in the system, would it not affect the behavior while it is not raining also?

i will try bedding the brakes.

videopho

I do have the similar issue as the original poster.
Brakes work fine in dry weather but when raining hard there seems to be a ms or two delay in braking which I think is somewhat dangerous.
Practically new pads and brand new tires in all four.

Rezno

iTrader: (1)

I've had this issue for a little bit but it tended to disappear as I drove the car a bit more. If it was raining, they would screech and not work as well. After I drove it for a few minutes, they seemed to work as they normally should.