RyanE Posted January 20, 2009 Share Posted January 20, 2009 Hi folks, One of the big things that has bugged me about my Legacy GT was the mushy brake pedal. I've bled the heck out of the thing, replaced the stock pads with Hawk HPS pads, and checked pedal free play. Some poking around this site and NASIOC got me to check the bottom of my master cylinder with a dental mirror, and lo and behold, we have a 15/16" bore diameter master cylinder. This is the smallest one on any Subaru! What does this mean? This means we have to push the pedal farther than someone with a WRX or STi to get the same amount of pressure to the brakes. It does make the pedal easier to push, but pushing farther makes it feel "mushy" and makes heel and toe driving harder. Soooo, the fix seems to be a larger WRX 1" or STi 1 1/16" master cylinder. Searching RockAuto.com and other sites for 1 1/16" Subaru master cylinders was confusing and contradictory. My question to you folks is what year and model 1 1/16" master cylinders will bolt up to our LGTs? I've learned that early WRXes had the same 1 1/16" master cylinder as the STis, but I don't know what years, and if it is the same part as the STi part. Also, does the STi part offer any advantage over the WRX part? Thanks in advance, Ryan Link to comment Share on other sites More sharing options...
PeterJMC Posted January 20, 2009 Share Posted January 20, 2009 This is interesting. Would like to know more about this topic. I hate my mushy brake pedal feel. Upgraded lines and Brembos and the brakes still mush. Link to comment Share on other sites More sharing options...
RyanE Posted January 20, 2009 Author Share Posted January 20, 2009 I've done some more poking since the OP, and it looks like at least the 2004 WRX and STi both have the 1 1/16" MC. Post #66 here: http://www.subaruforester.org/vbulletin/f68/brembos-sti-master-cylinder-replacement-rotors-brembo-owners-please-chime-21330/index5.html states that the poster was very happy with the results of replacing his 1" MC with a 1 1/16" MC on a Forester. Do we get extra win by going up 1/8"? -Ryan Link to comment Share on other sites More sharing options...
ronemus Posted January 20, 2009 Share Posted January 20, 2009 Using HPS pads with the attached anti-squeal plate (no Subaru OEM silencer shims) took the mush out of my brakes. I think most of the mush is due to the multi-layer shims Subaru uses - lots of slop to compress before the pads will bite. Link to comment Share on other sites More sharing options...
RyanE Posted January 20, 2009 Author Share Posted January 20, 2009 Yea, I ditched the OEM shims when I installed the HPS pads. I started a thread over on NASIOC on the same topic, and unclemat had some good input: http://forums.nasioc.com/forums/showthread.php?t=1681388 -Ryan Link to comment Share on other sites More sharing options...
Guest Posted January 20, 2009 Share Posted January 20, 2009 As I posted on nasioc the mushiness is: pads, lines and calipers. Addressing these 3 issues cured the mushiness. As I found out, 05+ Legacy and Outback w/VDC have different master cylinder - same as 2008-2009 STI. Link to comment Share on other sites More sharing options...
mwiener2 Posted January 20, 2009 Share Posted January 20, 2009 no mush for me My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
RyanE Posted January 20, 2009 Author Share Posted January 20, 2009 Guess I have to save my pennies for lines and see how that treats me. Thanks! Ryan Link to comment Share on other sites More sharing options...
praedet Posted January 20, 2009 Share Posted January 20, 2009 The stock calipers also flex a lot... I will say that pads, fluid and lines took 30-40% of the mush away. Different rotors took away another 30-40% actually. But, it was not till I switched to different calipers that there was no "mush"... Link to comment Share on other sites More sharing options...
rubberman Posted January 21, 2009 Share Posted January 21, 2009 As I posted on nasioc the mushiness is: pads, lines and calipers. Addressing these 3 issues cured the mushiness. As I found out, 05+ Legacy and Outback w/VDC have different master cylinder - same as 2008-2009 STI. I just wanted to clarify this to be sure that I understand... What about Legacy's w/o VDC, do they have a different MC? For example, I have an 05 LGT 5EAT w/o VDC - does it have the same MC part number as above? Link to comment Share on other sites More sharing options...
Guest Posted January 21, 2009 Share Posted January 21, 2009 No, Legacy w/VDC have a unique part # - for the small master brake cylinder. Given how well Brembos work with our master cylinder I'd not attempt to change it. Just get Brembos Link to comment Share on other sites More sharing options...
peteyjr Posted January 22, 2009 Share Posted January 22, 2009 Excellent, this is confirming what I have though all along. Could not understand why my WRX has so much better pedal feel. Even after going to Hawk HPS, DBS rotors and fluid/ss lines on my LGT Link to comment Share on other sites More sharing options...
praedet Posted January 22, 2009 Share Posted January 22, 2009 Smaller calipers flex less... Link to comment Share on other sites More sharing options...
Guest Posted January 22, 2009 Share Posted January 22, 2009 Smaller calipers flex less... 08 wrx has lgt calipers I believe.... Link to comment Share on other sites More sharing options...
praedet Posted January 22, 2009 Share Posted January 22, 2009 I don't know about that as it has smaller, thinner rotors, but the person above me is comparing an LGT to an 05 WRX Link to comment Share on other sites More sharing options...
Guest Posted January 22, 2009 Share Posted January 22, 2009 That's why said "I believe" (<-- read I might be wrong)... didn't notice 05 wrx above. Anyway, BBK overcomes any shortcomings of LGT's brake master cylinder, that' the important part Link to comment Share on other sites More sharing options...
praedet Posted January 22, 2009 Share Posted January 22, 2009 02-o5 WRX: 11.4" Vented Disc 2 piston floating Caliper Front, 10.6" Solid Disc 1 piston floating Caliper Rear 06-07 WRX: 11.5" Vented Disc 4 piston fixed Caliper Front, 11.3" vented Disc 2 piston fixed Caliper Rear 08-09 WRX: 11.6" Vented Disc 2 piston floating Caliper Front, 11.3" vented Disc 1 piston floating Caliper Rear 05-09 LGT: 12.3" Vented Disc 2 piston floating Caliper Front, 11.3" vented Disc 1 piston floating Caliper Rear I can't find the thickness on the disc, (which would hint at the Caliper info) but the front pads are different from 08+ WRX to LGT... Link to comment Share on other sites More sharing options...
D_J Posted January 23, 2009 Share Posted January 23, 2009 The stock calipers also flex a lot... I will say that pads, fluid and lines took 30-40% of the mush away. Different rotors took away another 30-40% actually. But, it was not till I switched to different calipers that there was no "mush"... Did you upgrade in that order? I just read the sticky that the rotors don't do much?! Seems that the slotted rotors would make a difference I thought. Don't want to drop some big money on calipers. Thinking about just SS lines, pads, new fluid...possibly DBA rotors. Not so sure about the rotors now after reading the sticky. Link to comment Share on other sites More sharing options...
praedet Posted January 23, 2009 Share Posted January 23, 2009 I did do it in that order... I was VERY suprised by the difference the Rotors made (2-piece iON Racing Rotors) as I have never had rotors effect "feel" at all, let alone as much as they did with the LGT... Link to comment Share on other sites More sharing options...
KartRacerBoy Posted January 23, 2009 Share Posted January 23, 2009 Makes one suspect your subjective evaluation praedet. Link to comment Share on other sites More sharing options...
D_J Posted January 23, 2009 Share Posted January 23, 2009 I did do it in that order... I was VERY suprised by the difference the Rotors made (2-piece iON Racing Rotors) as I have never had rotors effect "feel" at all, let alone as much as they did with the LGT... Clint was thumbs down on both slotted and drilled rotors. Seems that a lot of rotors are just for the "bling" factor. Mountain driving is no joke and make your brakes start to fade in no time. The SS lines are a must for mountain driving I hear. We don't have the type of moutains CO has but still very steep roads so good brakes are essential IMO. more from what Clint wrote: Rotors – Buy good rotors. Not unknown cheapy ebay ones that you have no idea who made them. Slotted – not really necessary unless you are heavily racing in the rain Drilled – NO NO NO a thousand times NO! Two piece, semi-floating or fully floating – there’s a time, a place and a budget for these. 99% of the cars on this board will never need this time place or budget. Quite honestly they are not necessary unless you're REALLY into autoX or the track, and chances are if you are into those things I'm not going to tell you anything you don't already know about them." Link to comment Share on other sites More sharing options...
RyanE Posted January 24, 2009 Author Share Posted January 24, 2009 Yea, both slotted and drilled rotors are unnecessary on street driven cars. Brake pads don't outgas like they used to, and the slots or holes eat up pads and reduce total thermal mass (and strength) of the rotors. I'm on a BMW mailing list from my dirty e30 days, and there were pictures circulating of an M3 that had a drilled rotor break, throwing the car off the track quite forcefully. Yikes. After thinking about this thread and what everyone has contributed to it, I think a better description of what I'm annoyed with is the length of the pedal travel before something starts to happen. That's why I think that a different sized MC would help me. -Ryan Link to comment Share on other sites More sharing options...
praedet Posted January 24, 2009 Share Posted January 24, 2009 Makes one suspect your subjective evaluation praedet. YOu can if you want, but some folks local drove my car and had everything but the rotors, and they noticed the difference also... I have changed the rotors in 3 cars and NEVER noticed anything. I didn't believe it either truly, until my wife said something about it... Link to comment Share on other sites More sharing options...
KartRacerBoy Posted January 24, 2009 Share Posted January 24, 2009 It's magic! I just enjoy giving you crap though. Any rational explanation? Link to comment Share on other sites More sharing options...
sic GT Posted January 24, 2009 Share Posted January 24, 2009 You should consider installing a master cylinder bracket. Cusco makes one. Many people say it is for the right hand drive cars only but my Subaru dealer was able to install mine w/ no problem. It will definitely help with the mushy feel especially under moderate to severe braking at which point the master cylinder itself will begin to bend away from the brake booster due to the booster slightly deflecting from the brake pedal pressure your foot will exert. Link to comment Share on other sites More sharing options...
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