1" ITR/GSR booster/master cylinder swap

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stmotorsports

Senior Member
1" ITR/GSR booster/master cylinder swap info

just dropping this in for search purposes...

Just finished doing this swap in my 2000 Civic Si. I did some research before starting this project only to find a lot of write-ups don't specify the one fitting you need to change when going from standard teg/civic size mc is the rear (closest to firewall). You need to get a 12mm x 1.0 to 3/16" line inverted flare fitting which apparently is somewhat uncommon. I called and drove around for half a day to all different parts stores in my area only to find that noone had one of these. Not by itself or on a section of repair line, nothing. Your best bet is to just go straight to a hydraulics supplier, I ended up getting one right away and it cost me just shy of $2.

btw fwiw, going from my stock Si 15/16"/270V mc & booster to the 1"/290V made bearly any difference at all. If you're considering this swap to improve your lackluster EM1 brakes don't bother. The good news is now you have an excuse to do the full 5-lug swap :)
 
yeah the only reason i really did it is because i found someone on one of the local boards parting a bunch of stuff out cheap & got it for next to nothing

plus I've been toying with the idea of a 5-lug swap anyways so I thought I'd get this out of the way
 
Ah, very nice. I was always for the sleeper effect, so I never even entertained the thought of going to a 5 lug setup. I can see why you got the 1" master though. 15/16" was good enough for me!
 
I wish I could rep you, but I have to spread some first.

Great information on the fitting. I have my ITR MC/BB just sitting because I couldn't find the correct fitting size. Mine is replacing a 7/8 stock MC in my Civic. It's already spongy with just 91 EX brakes swapped in(with DA calipers).
 
oh I see how it is... lol j/k

I'm all for the sleeper thing too but I autox with the car and the stock Si brake configuration just isnt cutting it... not even after complete system overhaul, going to full syn fluid, stainless lines, Hawk pads & Brembo blanks, and now the mc/bb swap. I've got a set of Porterfield race pads on the way as a last ditch attempt and then its either 5-lug for next year or bail on the Si altogether

the brakes on my stock GSR are great and it's basically the exact same setup, yet I've spoken with so many peeps that either have or have had 99-00 Si's that say the brakes were always weak... I just don't get it :hmm:
 
Just wondering, what hydrualic company did you buy the fitting from? I'm having problems sourcing that(many have M10x1 only).
 
Thanks man!

Just an update; I got it installed...and guess what? Advance Auto has a M12x1 to 3/16 adapter fitting.... :D
 

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nice :thumbsup:

none of the parts stores around here had any, not even napa
 
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Yea, I thought it was odd that out of all places(including a brake/hydraulic specialty shop) that Advance Auto had exactly what I needed.
 
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