Sti Master Brake cylinder swap Qs

Actually my post is in the other thread someone started. Just search my name in the other STI master cylinder thread

If I find it later ill post it up. Doing this from my phone so not so easy

I found your post.

 

 

They also had the numbers 061023 or FO1G061023 Some said Bosch on them

 

I could be wrong but from the research I did before I just purchased mine this is what i found.

 

The WRX booster looks the same but Im not sure it is totally the same.

 

This information came from a reputable STI only parts dealer http://www.y2kimports.com

 

I looked at the pictures on ebay again at the one I bought and I was able to read out the numbers:

 

F01G061025 SL

6209

Bosch Automotive system corp.

 

What does that suggest ?

 

 

I also called the seller and ask if it IS an sti. He said he listed them as both wrx ans sti because the parts looked identical, but the part was pulled out of an wrecked sti. The weird thing is that he re-listed the item, but had mine ship out today.

Im not really sure..... I know from what y2kimports.com told me that it had to be the 061023 number and SJ for it to be an STI booster. At least for the 05-07

 

Oh an by the way those pictures may mean nothing. When I bought mine off ebay I was sent a totally different booster than in the pictures.

 

I filed a complaint and was able to get my money back and keep the booster. That booster ended up being a STI booster but I purchased another one from y2kimports.com

Edited November 25, 2012 by Scooby2.5

Can anyone confirm based on piston size ?

 

I got the mbc today and took it apart for pics.

 

http://i344.photobucket.com/albums/p330/ibr_adam09/photo2-1.jpg

http://i344.photobucket.com/albums/p330/ibr_adam09/photo5.jpg

http://i344.photobucket.com/albums/p330/ibr_adam09/photo4-1.jpg

http://i344.photobucket.com/albums/p330/ibr_adam09/photo3-1.jpg

On the bottom of the master cylinder it will have the piston size stamped in the metal.

 

Im just not sure about it due to the part numbers. It could be an STI but it may be a WRX.

 

I know the SJ with the 23 on the end were indeed STI. You could call y2kimports, they may know

Ok, so I took a look and it stamped "1". I heard the sti is 1- 1/16th ? It's probably a Wrx.

 

Since the LGT is 15/16, would it still be an 'upgrade'. Assuming everything will fit ?

It might be, but I would return it and get your money back or tell them to sen you a STI one.

Left a message to the seller. I do see another sale on ebay that has the correct part numbers, but I'll see what the seller says first.

02-05 WRX MT = 1 1/16" or 26.99mm bore diameter

06-07 WRX MT = 1" or 25.4mm bore diameter

04-07 STi = 1 1/16" or 26.99mm bore diamete

What about the VDC equipped LGT or 3.0R??

do you think that it'll make a difference swapping our MBC??

 

I have a complete brembo setup with SS Lines, DBA 4000 rotors, HAWK HP+ pads and waited for my Grimmspeed MBC Brace to arrive.

What about the VDC equipped LGT or 3.0R??

do you think that it'll make a difference swapping our MBC??

 

I have a complete brembo setup with SS Lines, DBA 4000 rotors, HAWK HP+ pads and waited for my Grimmspeed MBC Brace to arrive.

 

Oh of course it will. Keep in mind this is a "feel" mod doesn't affect brake performance at all. The bigger bore takes away that soft mushy Subaru brake pedal.

 

Problem is this is a tough mod in a VDC car. See above for the link to monkiboys adventure on his WRX the procedure would be the same. Cliff notes: VDC cars have different size tubes and fittings which you need to adapt.

So everything is in. I have to say its easier putting it in then taking it out. I guess becuase the lgt booster is bigger.

 

Anyhow, I bleed the front brakes and bench bleed the mc. I haven't driven on it yet( motor is out), but I get a squealing/creaking noise when you press the pedal. It's bit more noticable when the pedal decompresses. I'm thinking its spring inside the mc. Maybe from not being used in a while ? Doesn't sound alarming, just annoying.

I remember reading somewhere that the newer sti's have the same MC as the vdc legacies, and that only the booster was different, as opposed to the '04-'07 sti's 1-1/16" MC.

 

Not sure if that's correct, but if it is then the vdc people may want to just swap the sti booster for a better pedal feel, not having to deal with the different sized fittings on the MC.

newer sti's 08+ have the same sized mc as us. Its the 04-07 STI's that got the bigger MC

has anyone ever tried doing this on a VDC equipped legacy?

no confirmation?

This is an old thread, but still relevant. I did the upgrade on my 2005 Outback 3.0R using the MC and booster from an '03 WRX. What a difference!!! Much, much better. I put together a couple of videos to describe what I did.

 

 

Edited June 2, 2020 by me73

For anyone who's looking for Monkiboy's adventure getting his STi M/C to fit a VDC Legacy, the old forum thread that's linked a few pages back is gone (the whole forum is gone now, not just the thread). He posted on this one as well and it pretty much outlines the problem and what he did to resolve it: https://www.wrxforums.com/threads/master-brake-cylinder-swap-better-pedal-feel.19309/

 

 

Basically the VDC Legacy (and Outback) hard lines are larger than what was used in an '04-'07 STi, so you have to get a line adapter...which makes the side-attached line too long to fit in the space available for it. He had to cut and re-flare his line, which turned out to be a major hassle.

For anyone who's looking for Monkiboy's adventure getting his STi M/C to fit a VDC Legacy, the old forum thread that's linked a few pages back is gone (the whole forum is gone now, not just the thread). He posted on this one as well and it pretty much outlines the problem and what he did to resolve it: https://www.wrxforums.com/threads/master-brake-cylinder-swap-better-pedal-feel.19309/

 

 

Basically the VDC Legacy (and Outback) hard lines are larger than what was used in an '04-'07 STi, so you have to get a line adapter...which makes the side-attached line too long to fit in the space available for it. He had to cut and re-flare his line, which turned out to be a major hassle.

 

funny reading the DIY a decade later. it made a very noticeable difference and ultimately, now that we know what to do and avoid, isn't that much of a hassle. hope it helps!

Monkiboy lives!! Hope all is well bud it's been a long time since we were hacking parts into Subarus ;-) Getting these old thread notifications brings the memories back.

Monkiboy lives!! Hope all is well bud it's been a long time since we were hacking parts into Subarus ;-) Getting these old thread notifications brings the memories back.

my friend! thank you for replying. yes, what a fun blast from the past. hope you and yours are well.

We'll looks like I've done it again. I went ahead and found a low mileage replacement STI M/C and Booster, aaaaaaand I didn't read the thread completely. So as per the linked post above I'll be venturing off and buying a flare tool and making mine actually fit. Since there isn't an off the shelf, or garage workbench made solution I can just buy. Mokiboy your info was super helpful.

We'll looks like I've done it again. I went ahead and found a low mileage replacement STI M/C and Booster, aaaaaaand I didn't read the thread completely. So as per the linked post above I'll be venturing off and buying a flare tool and making mine actually fit. Since there isn't an off the shelf, or garage workbench made solution I can just buy. Mokiboy your info was super helpful.

 

glad to hear it got some use and the info was helpful - good luck!

So I just completed the STI mc/booster install on my 07 LGT w/vdc. After doing some cutting, flaring, and adapting to my existing line, I love it.

 

What I have left is dialing in the pedal distance. Which seems to take only 1-1.5 rotational turn of the booster rod to go from partially locked brake pedal, to "Holy shit, where did my brakes go!" (I measured before hand and adjusted it, but somehow got it wrong, twice) then I thought I had it right where it needed to be but saw an ABS light come when I backed into the garage (after a test drive) but does go away on restart. So there is that.