Topic: Grimmspeed - Master Cylinder Bracket 08 STI

[nitram]

So my car had the following problem:

http://forums.nasioc.com/forums/showthread.php?t=2184210
http://www.3gwrx.com/forum/index.php?topic=9261.135

- cracked firewall
- squeaking brake pedal
- excessive movement in the assembly (brake moves as clutch is depressed)

Subaru was good enough that they covered for the repair even though i was outside of the warranty. However i was worried it will happen again especially since even after the repair, the brake pedal movement is still quite significant.  After some research and my own diagnosis, i figured the Grimmspeed MCB should help prevent it or at least reduce the chance of it happening again.

Here are the before and after video (however don't have video of the squeak and movement before subaru repaired the welds).  You can be the judge for yourself to see if it's worthwhile to install as a preventive measure.  From my research, seems to be a common problem for 08+ impreza (not just STi)

before:
after:

[rith]

Doesn't look too much different to be honest (maybe a mm or 2) , the brace is supposed to stop the firewall flex up near the top when the cylinder is under pressure, doesn't seem to do much when your whole firewall is flexing even when you push the clutch...   :/  It might stop a little bit of the flex but that's crazy..  I'd email SoC and tell them the fix is still unacceptable. I've never heard of that firewall issue before on the 08/09's.. crazy stuff.

[nitram]

Yea i was slightly disappointed it didn't totally stop it from moving, but i would say it does help.  Even a new STi in the dealership showroom has this brake pedal movement (but very slightly - less than my 'after' video).  I'm assuming that the firewall is already weakened from the damage hence only the slight improvement, but an improvement none the less.

As for not hearing about this, there is a bulletin on this and subaru is aware it is a problem. But there is no recall (probably due to the cost of the repair). 

[rith]

Where is it breaking exactly? On some seams/welds near the pedal mounts? Makes me want to check my car now hah.

[nitram]

http://www.3gwrx.com/forum/index.php?topic=9261.390

there's some pics closer to the bottom of this page.  This is one way people have found out how to see if the welds are broken, will need to remove front driver side wiper motor assembly.  However to properly see and repair the problem, the whole dash has to be removed.

[rith]

Ah, thats funny..  the unibody sheets are pulling apart at the spot welds..

[TalsniC]

Brake pad selection, brake fluid flush (remove air if present) could also help.

I drove a buddy's STI with stock pads, and immediately the brakes felt much more spongy compared to my STI with Ferodo DS2500's.  Pad compressibility makes a differance.  The DS2500's do like to make noise once and a while though.   

[rith]

Brake pad selection, brake fluid flush (remove air if present) could also help.

I drove a buddy's STI with stock pads, and immediately the brakes felt much more spongy compared to my STI with Ferodo DS2500's.  Pad compressibility makes a differance.  The DS2500's do like to make noise once and a while though.   

lol, you obviously didn't watch the video that closely, he was pressing his clutch in and the entire pedal assembly was moving