Author Topic: STi brake problem... (Read 4832 times)

bobbyC · « **on:** March 28, 2011, 09:24:42 am »

I know its a common issue with the Brembo brakes to freeze on STi's when your "playing" in the snow and have basically no brakes... But from a stand still when your car is parked for less than 24hrs and a 1cm of snow fallen in that time frame is a little redonkulars thus causing me to run through a stop sign and almost get t-boned

/rant

How often does this happen to you? I sure hope this get solved for the next gen Subaru's...

LilDrunkenSmurf · « **Reply #1 on:** March 28, 2011, 09:33:05 am »

Never had that problem before *shrug*

GrantC · « **Reply #2 on:** March 28, 2011, 10:25:13 am »

Stock pads? Much snow/ice buildup in the wheels?

bobbyC · « **Reply #3 on:** March 28, 2011, 10:45:50 am »

Quote from: GrantC on March 28, 2011, 10:25:13 am

Stock pads? Much snow/ice buildup in the wheels?

yes they are stock pads with approx 10,000kms on them and no build up of ice or snow in the wheels.

Tenacious_B · « **Reply #4 on:** March 28, 2011, 11:19:02 am »

Quote from: bobbyC on March 28, 2011, 09:24:42 am

I know its a common issue with the Brembo brakes to freeze on STi's when your "playing" in the snow and have basically no brakes... But from a stand still when your car is parked for less than 24hrs and a 1cm of snow fallen in that time frame is a little redonkulars thus causing me to run through a stop sign and almost get t-boned /rant

How often does this happen to you? I sure hope this get solved for the next gen Subaru's...

The only time I have no brakes is immediately after a car wash when the rotors are still wet.

funk32 · « **Reply #5 on:** March 28, 2011, 11:41:39 am »

I have had this issue, like stated above, car washes on cold days or after a good run in the snow. I was told that sloted rotors and better pads will fix this problem.

energie · « **Reply #6 on:** March 28, 2011, 11:53:33 am »

Quote from: Tenacious_B on March 28, 2011, 11:19:02 am

The only time I have no brakes is immediately after a car wash when the rotors are still wet.

+1

snackers · « **Reply #7 on:** March 28, 2011, 12:15:51 pm »

Quote from: bobbyC on March 28, 2011, 09:24:42 am

I know its a common issue with the Brembo brakes to freeze on STi's when your "playing" in the snow and have basically no brakes...

So what is the difference between brembos and regular WRX brakes that causes this on the STI?
Yes, I know the differences between the calipers/rotors/pads themselves, but what is the "consensus" that you say is causing this specifically on the STI?

I have never had this problem on an impreza, forester, or wrx after car wash, winter autox, or parking lot shennanigans.

funk32 · « **Reply #8 on:** March 28, 2011, 12:17:31 pm »

I was told it was due to the size of the rotor.

Zaider · « **Reply #9 on:** March 28, 2011, 12:49:11 pm »

I haven't had that with snow... but after a car wash, my brakes are a little soft the first time i use them... i've just gotten used to driving for about 20m and then braking to get the water off the pads/rotors.

Ambystom01 · « **Reply #10 on:** March 28, 2011, 12:54:36 pm »

I don't see how the rotor size would cause this. The rotor is about an inch bigger but unless you're moving really fast, I really doubt the increased surface area could cause such a dramatic temperature difference as to render the stock pads useless. Hell, the OP suggests the car was parked for some time yet I've never experienced no brakes even after leaving my car outside for days. Like Zaider, I've had softer brakes after a car wash or even after cruising for a long time but I still had brakes. This is with Carbotech AX6s that should be fairly similar to the stock pads on an STI. Maybe something else is wrong, when was the last time the fluid was changed?

Elias · « **Reply #11 on:** March 28, 2011, 01:09:47 pm »

I had this problem with the OEM pads, especially after car washes. I switched to Endless SSY's from Vex and they are flawless! You may want to consider a pad upgrade

Tenacious_B · « **Reply #12 on:** March 28, 2011, 01:16:49 pm »

I would think it's the pad compound personally. I find that as the pad gets older its getting worse on mine. Its worse now than a year ago.

bobbyC · « **Reply #13 on:** March 28, 2011, 04:03:50 pm »

I'm just not too impressed since i only have 10000kms on the car which i just picked up in Sept of 2010... The only thing i could think of that may have caused this is humidity/precipitation in the air from the 1cm of snow that dusted my car. Other than that, i have not washed my car for a good week or so. Thanks for the brian storming though!

Munky · « **Reply #14 on:** March 28, 2011, 04:06:44 pm »

In my wrx, There were 2 occasions this winter when it was really cold, nights below -20, and there was a bit of moisture in the air that my brakes felt like I had just got them wet. After a few firm stops they were good again.

khris08 · « **Reply #15 on:** March 28, 2011, 04:23:04 pm »

Never happen to me before

... maybe brake lines were clogged up.

goalieboy1 · « **Reply #16 on:** March 28, 2011, 06:34:09 pm »

can you just clarify something that is pretty important....when you said you had no brakes, what did the pedal do? drop to the floor or was it rock hard at the top?

~Touge/Wangan- · « **Reply #17 on:** March 28, 2011, 06:35:40 pm »

happened to me almost a week ago when we had "ice fog" or whatever weathernetwork forcasted, i pulled out of my complex and went to stop. low and behold, i had no brakes and rolled into the street freaking myself out.

i dont even have brembo's

Ambystom01 · « **Reply #18 on:** March 28, 2011, 07:02:55 pm »

Jesus, what pads and fluid are you guys running?

bobbyC · « **Reply #19 on:** March 28, 2011, 07:27:30 pm »

Quote from: goalieboy1 on March 28, 2011, 06:34:09 pm

can you just clarify something that is pretty important....when you said you had no brakes, what did the pedal do? drop to the floor or was it rock hard at the top?

Your right, that is important. I could feel that there was pressure in the pedal but there was no stopping... T

Ambystom1: they are the stock brembos that come with the car.

~Touge/Wangan- · « **Reply #20 on:** March 28, 2011, 09:36:24 pm »

i have stock rotors with 2006 calipers and HPS+ pads

goalieboy1 · « **Reply #21 on:** March 28, 2011, 09:42:06 pm »

Ok i have came across this in my car as well-touge id imagine this relates moreso to you but it could be the same issue with the brembo pads, cant say for sure.

I had driven my car for one winter on factory pads. never had any issues. the summer following I changed to Hawk HPS+ pads as well and that winter, until the pads heated up they were useless. Its scary to say the least. I cant tell you the exact science of it but heat in the pads will make them more effective than if they just sat outside in the freezing cold. what I started to do (as ghetto as it seems) was for the first little while I was driving, just hold your foot on the brake with a little bit of pressure, just to warm them up a bit. Or I guess you could use a hair dryer

Ambystom01 · « **Reply #22 on:** March 28, 2011, 09:44:53 pm »

Quote from: ~Touge/Wangan- on March 28, 2011, 09:36:24 pm

i have stock rotors with 2006 calipers and HPS+ pads

Quote from: goalieboy1 on March 28, 2011, 09:42:06 pm

Ok i have came across this in my car as well-touge id imagine this relates moreso to you but it could be the same issue with the brembo pads, cant say for sure.

I had driven my car for one winter on factory pads. never had any issues. the summer following I changed to Hawk HPS+ pads as well and that winter, until the pads heated up they were useless. Its scary to say the least. I cant tell you the exact science of it but heat in the pads will make them more effective than if they just sat outside in the freezing cold. what I started to do (as ghetto as it seems) was for the first little while I was driving, just hold your foot on the brake with a little bit of pressure, just to warm them up a bit. Or I guess you could use a hair dryer

I presume you mean HP+ right? There is no Hawk pad called the HPS+. It really sounds like there may be some other issue at hand or there's a big variation in terms of what people think "no brakes" means. I've had a variety of pads, including the Hawks, and never observed this issue. The HP+ (or HPS if that's what you have) are not hardcore race pads that require a itshay ton of heat in them to work, they should be fine from more or less ambient to fairly high temps. The reason for the phenomenon you're describing (heat makes them work better) is the material used to make the pad. The coefficient of friction of the material is heat dependent, much like ski wax.

You could try changing the fluid to see if that remedies the problem. The only reason I say that is if the fluid is old, maybe there's water or air in it and when the car sits or it's especially cold out, somehow that's causing an inability to form pressure in the system. I'm sure the stock pads aren't fantastic at cold temperatures but to have no brakes at all seems kind of crazy to me. You would also think that if it was the pad material, it would be far more common and predictable.

goalieboy1 · « **Reply #23 on:** March 28, 2011, 09:50:32 pm »

I stand corrected, I actually have the HPS, no plus in there. And by no brakes I mean reduced stopping power.

You are also correct in saying there could be water in the system "freezing" seeing as brake fluid is hygroscopic but air would be a soft pedal. In my instance though, I did a brake fluid flush at the same time as the pad change which is why I had put it on the pads

Ambystom01 · « **Reply #24 on:** March 28, 2011, 09:54:37 pm »

Did you bed the brakes in? If you didn't bed them in properly, this could explain why they suck. The HPS are one of Hawk's tamest pads and are designed as a stock replacement. Water should also produce a soft pedal as if it boils, it becomes air. However, that's dependent on it boiling.