monkiboym

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!

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.

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!

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

You're confusing hill-assist with brake assist. Different things.

you're right. i need more sleep and pay closer attention. sorry, guys!

'08 WRX has this. Subaru calls it Brake Assist. I have a reward ready for whoever can disable this 'feature'.

you didn't mention caring about any other "features" (ABS, cruise control, etc), so your solution is to remove the fuse. voila, no more hill-assist.

now, where do i collect my reward?

I prebled the MC on the bench (covered the holes with plastic stoppers and let the fluid squeeze around them) so there were no major air pockets and then bled as normal with the caliper valves once it was in the car. Had no issues but I used a power bleeder and lots of fluid.

+1, you'll want to bench bleed the MC first. more detail and/or instructions are in your FSM.

Just a heads up, you are going to have your work cut out for you swapping this on a VDC car. I have been following Monkiboy and gave him the heads up about this thread.

 

What we did not know at the time, is that all the VDC cars have bigger brake line with larger fittings to the MC (12x1mm vs 10x1 thread). Everyone who has done the swap in this thread appears to have an earlier Legacy pre-VDC which has the smaller fittings to match the STI MC, so it bolted right on.

 

On a VDC car, you will need to cut off the ends of your lines going to the MC, slip on a 10x1 threaded fitting, and re-flare with a double flare tool. Monkiboy tried adapters but they add too much length to the line coming out the side of the MC to clear the strut tower.

 

If you check the link to 3gwrx above, you can follow Monkiboy's progress as he works out the issues.

this is a very important post for those affected. thanks power6! i'll make sure to keep my progress up to date but you nailed my status down. waiting on a union fitting and am going to cut the line down a bit and then use a union and two male tube nuts to run new line where the old kinked to make sure i bend it (with tube bender pliers for tight radius turns) to the port safely and without kinks and i should be good.

i'm doing this swap on my 08 wrx which may relate with you newer gens. i have a detailed thread about it here (http://www.3gwrx.com/forum/index.php/topic,20410). someone referred me to this thread and the potential for problems.

i have specific bore diameter information for the different MYs, more photos, and lastly noticed that my car appears to have a check valve already installed in the hose so you may want to double check before shoving on in there.

hope it helps. i'll be sure to post up information in my thread for reference and process for the unfamiliar.

thanks!