Wet Braking problems '06 STI

scrawshaw · 06-20-2008, 08:48 AM

Like many others, I have noticed issues with the brakes on my 2006 STI in the wet.

The first Winter, I noticed a several second delay between brake application and any stopping power in cold rain, if you did not touch the brakes for 10 min. or so.

Last Winter, that issue changed to include a strong pull to the left when the brakes finally did come on and a similar feeling, sometimes right after you started driving, if it was wet, even if you parked inside. I also noticed in the dry, the braking power seems reduced, or at least the initial bite of the brakes is reduced and I may be detecting a little bit of fade. Once last Winter, the brakes stuck so hard after being parked inside wet, I had to rev it a bit and dump the clutch in the reverse to get it moving. I also noticed that warm rain now causes the problem too.

When I took the snows off, I noticed that the left rear pads were worn more than the right rear (still plenty of pad on all 4 corners though, at 22k) and the clip on top of the caliper that holds the pads was crooked and not secure properly with the 2 clips that you slide to one side. At that point, I showed it to the dealer. They found nothing, but the clip is now straight. (although several weeks later, when I first looked at it, I noticed that one of the sliding clips that hold the clip on is not in the right position) The issue still remains. With one or two exceptions, nobody has said anything about a pull.

Any ideas about what I should do next?

fweasel · 06-21-2008, 07:35 AM

A Legacy owner at legacygt.com described the exact same problems as you with his new Brembo set-up. I PM'd him a link to this thread, not sure if he has any new insight or if it happened again.

kartracerboy · 06-21-2008, 08:39 AM

I've had two problems with my STi Brembos (front & rear) that I installed new on my LGT. This past winter I had the same problem as you when I started the car. It was below freezing outside but well above in my garage. I released the hand brake and went to back out of my garage but the rear brakes stuck. I popped the clutch (but not too aggressively) to break the rear free but no good. I eventually jacked up the car on, took off the wheels and took a rubber mallet to the rotors thinking it was the handbrake. I broke it free but then I noted a rust pattern on the rotors that was the shape of the brake pads. Hmmmmmm. It happened numerous times after this but to nowhere that extent and popping the clutch broke it free. Usually it was just a noise of the pads (I think) breaking loose of the rotors as I backed up as they barely stuck. This only happened when it was cold.

This May I drove to Florida from Indiana and it rained very heavily the entire drive. If I hadn't used the brakes for several minutes and I then hit the brake pedal, the car pulled hard to one side as if there was water between the pads and rotors. My installer foolishly removed my dust shields so I thought it might be the reason but I've since reinstalled them. I havent' driven insuch a downpour since so I can't say if the lack of shields were the problem. I also have a very open wheel design (Rota Boosts) so that may be a factor on the pulling problem as well.

In city driving, rain hasn't been an issue. fweasel has tracked his LGT and he has f/r STi Brembos, too, and he has not noted this problem even on soaking wet track days.

jermdeez · 06-21-2008, 10:36 AM

One time I almost wrecked due to this, but it turned out I had a low tire......going to fast in rain trying to speed up and then slow back down for a left turn, the brakes just grab my car and took it sideways while braking straight.........turned out my tire had like 14 psi on 1 side.

sounds like something got fooked up, I dunno if the snow tires could contribute? Id say if you are really worried get new pads all around and allign..................

also I'd have the fluid changed etc..........I hear the sti MC is very tough to work with......maybe its not functioning correctly?

MGizzle · 06-21-2008, 11:35 AM

Well, there is nothing wrong with your brakes. If you are really worried about this, get slotted rotors.

When I used to go to a touchfree carwash with the stock brakes I could not break coming out of it on a slight down hill slope due to all the crap on the rotors. When I switched to the sloted ones I have NO problems with this.

However, don't be worried. Wet braking is not effected by disc face as long as you put HIGH pressures on the brake pedal. As far as what you are describing above it is normal and they way to solve it is to apply the brakes here and there sometimes (drag them a bit). When I drive in the winter I drag my brakes from my drive way all the way up to the main street. Not under significant pressure, just draging. Then I do a couple of MEDIUM brake stops to get stuff cleaned up and put some heat into the system.

They way the OEM's are solving this is (I am sure you heard about the Mercedes system on the new S class) they apply brakes electronically by commanding the ABS/ESP unit. You have sensors in the car that know if it is raining or not and when they notice water they slightly drag the pads every couple minutes or so to make sure they are operational for a panic brake event. Pretty cool if you ask me.

Anyhow, nothing wrong with your brakes. Just be aware of it and get your brakes ready for panic stops.

***wdb*** · 06-23-2008, 07:58 PM

Quote:

Originally Posted by MGizzle

When I used to go to a touchfree carwash with the stock brakes I could not break coming out of it on a slight down hill slope due to all the crap on the rotors. When I switched to the sloted ones I have NO problems with this.

Same here, 40k miles on slotted rotors without a single "OMG NO BRAKES" moment. But I only put slotted rotors on the front. This poster seems to think there is something going on with the rear brakes.

MGizzle · 06-24-2008, 08:18 AM

Well, your pull might be just due to your tire alignment. Under braking it is mostly dicated by the front two tires because of weight transfer. As far as the spring not being aligned properly with the two pins, that is a easy fix and could possibly change the preload on the pads slightly, however not in the direction of wear.

I guess I don't think you have a brake problem. You might just be jerking your knee like I do a lot about any little change in the car. All the environment scenarios you have posted above could lead to what you are reporting.

Things I would check.

1: Make sure you torque your lugs right. Overtorquing will push the rotor closer to the inside and influence your pad wear. I torqued mine to 100 ftlbs when I just got it and noticed significantly more wear on the inside pad. I don't see it anymore with correct wheel lug torque.

2: Pull your pads out and look at them from the side (as if you are loking from behind the caliper while it is on the car. Look if they are wearing unevenly. I had this problem too when using the stock shims on certain aftermarket pads, especially when they were new. This will reduce brake output on that wheel significantly I think because your piston is not flat against the backing plate.

3: When you notice this problem, drag your brakes for 20-30 seconds and see if it is still there. Maybe too much build up of road debris/rust is influencing your first brake apply. The drag should clean/burn this off and the brakes should be bitting better.

4: If the above doesn't do anything go to a lot or something with some nice puddles. Do 1-2 brake in runs (40-60mph 80% stops to 5mph) and run through a couple of puddles afterwards. Make sure right after that to do another break in run (shortly after). See how that run felt and if the brakes are back. If they are, water has no effect on them and it is road debris/rust build up on your rotor face that is causing it. Of course hotter rotors will help too now but they shouldn't be too hot from just 1-2 stops and then runing through puddles.

scrawshaw · 06-24-2008, 09:29 AM

Thanks for the reply!

The tire wear looks good and the car doesn't pull when off the brakes or braking in the dry, so I doubt the alignment is off.

The wheel torque has always been spot on. (I'm really carefull about that) The brake pad wear is even between inside and outside pads too.

Haven't removed the pads yet. Not sure if the dealer did when I complained. Something to do for sure.

06-20-2008, 08:48 AM	#1
scrawshaw Lurker Posts: 2 Join Date: Mar 2007 Trader Rating: (0)	Wet Braking problems '06 STI Like many others, I have noticed issues with the brakes on my 2006 STI in the wet. The first Winter, I noticed a several second delay between brake application and any stopping power in cold rain, if you did not touch the brakes for 10 min. or so. Last Winter, that issue changed to include a strong pull to the left when the brakes finally did come on and a similar feeling, sometimes right after you started driving, if it was wet, even if you parked inside. I also noticed in the dry, the braking power seems reduced, or at least the initial bite of the brakes is reduced and I may be detecting a little bit of fade. Once last Winter, the brakes stuck so hard after being parked inside wet, I had to rev it a bit and dump the clutch in the reverse to get it moving. I also noticed that warm rain now causes the problem too. When I took the snows off, I noticed that the left rear pads were worn more than the right rear (still plenty of pad on all 4 corners though, at 22k) and the clip on top of the caliper that holds the pads was crooked and not secure properly with the 2 clips that you slide to one side. At that point, I showed it to the dealer. They found nothing, but the clip is now straight. (although several weeks later, when I first looked at it, I noticed that one of the sliding clips that hold the clip on is not in the right position) The issue still remains. With one or two exceptions, nobody has said anything about a pull. Any ideas about what I should do next? This ad is not endorsed by this member. Please register or login to hide this ad.

06-21-2008, 07:35 AM	#2
fweasel Amateur STI Driver Posts: 18 Join Date: Mar 2006 Trader Rating: (0)	Re: Wet Braking problems '06 STI A Legacy owner at legacygt.com described the exact same problems as you with his new Brembo set-up. I PM'd him a link to this thread, not sure if he has any new insight or if it happened again.

06-21-2008, 08:39 AM	#3
kartracerboy Lurker Car: GRP 05 LGT Fav Mod: Coming Soon Posts: 1 Join Date: Jun 2008 Trader Rating: (0)	Re: Wet Braking problems '06 STI I've had two problems with my STi Brembos (front & rear) that I installed new on my LGT. This past winter I had the same problem as you when I started the car. It was below freezing outside but well above in my garage. I released the hand brake and went to back out of my garage but the rear brakes stuck. I popped the clutch (but not too aggressively) to break the rear free but no good. I eventually jacked up the car on, took off the wheels and took a rubber mallet to the rotors thinking it was the handbrake. I broke it free but then I noted a rust pattern on the rotors that was the shape of the brake pads. Hmmmmmm. It happened numerous times after this but to nowhere that extent and popping the clutch broke it free. Usually it was just a noise of the pads (I think) breaking loose of the rotors as I backed up as they barely stuck. This only happened when it was cold. This May I drove to Florida from Indiana and it rained very heavily the entire drive. If I hadn't used the brakes for several minutes and I then hit the brake pedal, the car pulled hard to one side as if there was water between the pads and rotors. My installer foolishly removed my dust shields so I thought it might be the reason but I've since reinstalled them. I havent' driven insuch a downpour since so I can't say if the lack of shields were the problem. I also have a very open wheel design (Rota Boosts) so that may be a factor on the pulling problem as well. In city driving, rain hasn't been an issue. fweasel has tracked his LGT and he has f/r STi Brembos, too, and he has not noted this problem even on soaking wet track days.

06-21-2008, 10:36 AM	#4
jermdeez Spec C Club Posts: 1,699 Join Date: Feb 2005 Trader Rating: (1)	Re: Wet Braking problems '06 STI One time I almost wrecked due to this, but it turned out I had a low tire......going to fast in rain trying to speed up and then slow back down for a left turn, the brakes just grab my car and took it sideways while braking straight.........turned out my tire had like 14 psi on 1 side. sounds like something got fooked up, I dunno if the snow tires could contribute? Id say if you are really worried get new pads all around and allign.................. also I'd have the fluid changed etc..........I hear the sti MC is very tough to work with......maybe its not functioning correctly?

06-21-2008, 11:35 AM	#5
MGizzle Professional STI Racer Car: 05 STi OBP Fav Mod: Data Acq System Location: Warren, Michigan Posts: 773 Join Date: Jul 2006 Trader Rating: (1)	Re: Wet Braking problems '06 STI Well, there is nothing wrong with your brakes. If you are really worried about this, get slotted rotors. When I used to go to a touchfree carwash with the stock brakes I could not break coming out of it on a slight down hill slope due to all the crap on the rotors. When I switched to the sloted ones I have NO problems with this. However, don't be worried. Wet braking is not effected by disc face as long as you put HIGH pressures on the brake pedal. As far as what you are describing above it is normal and they way to solve it is to apply the brakes here and there sometimes (drag them a bit). When I drive in the winter I drag my brakes from my drive way all the way up to the main street. Not under significant pressure, just draging. Then I do a couple of MEDIUM brake stops to get stuff cleaned up and put some heat into the system. They way the OEM's are solving this is (I am sure you heard about the Mercedes system on the new S class) they apply brakes electronically by commanding the ABS/ESP unit. You have sensors in the car that know if it is raining or not and when they notice water they slightly drag the pads every couple minutes or so to make sure they are operational for a panic brake event. Pretty cool if you ask me. Anyhow, nothing wrong with your brakes. Just be aware of it and get your brakes ready for panic stops.

06-24-2008, 08:18 AM	#7
MGizzle Professional STI Racer Car: 05 STi OBP Fav Mod: Data Acq System Location: Warren, Michigan Posts: 773 Join Date: Jul 2006 Trader Rating: (1)	Re: Wet Braking problems '06 STI Well, your pull might be just due to your tire alignment. Under braking it is mostly dicated by the front two tires because of weight transfer. As far as the spring not being aligned properly with the two pins, that is a easy fix and could possibly change the preload on the pads slightly, however not in the direction of wear. I guess I don't think you have a brake problem. You might just be jerking your knee like I do a lot about any little change in the car. All the environment scenarios you have posted above could lead to what you are reporting. Things I would check. 1: Make sure you torque your lugs right. Overtorquing will push the rotor closer to the inside and influence your pad wear. I torqued mine to 100 ftlbs when I just got it and noticed significantly more wear on the inside pad. I don't see it anymore with correct wheel lug torque. 2: Pull your pads out and look at them from the side (as if you are loking from behind the caliper while it is on the car. Look if they are wearing unevenly. I had this problem too when using the stock shims on certain aftermarket pads, especially when they were new. This will reduce brake output on that wheel significantly I think because your piston is not flat against the backing plate. 3: When you notice this problem, drag your brakes for 20-30 seconds and see if it is still there. Maybe too much build up of road debris/rust is influencing your first brake apply. The drag should clean/burn this off and the brakes should be bitting better. 4: If the above doesn't do anything go to a lot or something with some nice puddles. Do 1-2 brake in runs (40-60mph 80% stops to 5mph) and run through a couple of puddles afterwards. Make sure right after that to do another break in run (shortly after). See how that run felt and if the brakes are back. If they are, water has no effect on them and it is road debris/rust build up on your rotor face that is causing it. Of course hotter rotors will help too now but they shouldn't be too hot from just 1-2 stops and then runing through puddles.

06-24-2008, 09:29 AM	#8
scrawshaw Lurker Posts: 2 Join Date: Mar 2007 Trader Rating: (0)	Re: Wet Braking problems '06 STI Thanks for the reply! The tire wear looks good and the car doesn't pull when off the brakes or braking in the dry, so I doubt the alignment is off. The wheel torque has always been spot on. (I'm really carefull about that) The brake pad wear is even between inside and outside pads too. Haven't removed the pads yet. Not sure if the dealer did when I complained. Something to do for sure. This ad is not endorsed by this member. Please register or login to hide this ad.