Question.... I did a rear disc swap on a 91 dx.
I have the crx si rear setup.
Everything works but I need a MC and or booster.
I've read that you need a 15/16 MC, this is fine until today when I went to order it I found out you can use the " 15/16 MC " from a 88-91 prelude, 89or so accord LXi, and 90-91 civic EX.
Is it possible to just get a prelude 15/16 and still have the same results?
( its way cheaper than a new integra MC and booster )
I just want the best brake pedal firmness and most stopping out of my all wheel slotted discs.
Thanks in advance for any help.

 

90-91' Civic EX master cylinder is what you want... you won't have to touch the brake booster. I hope you got the 40/40 proportioning valve to go along with your swap.

 

Ok thanks... and yes I already have the 40/40 valve.

 

so if you have these then all you have to do is bleed the brakes...?

i have the 90-91 ex brake booster also but if its not required to change then this sounds much easier.

 

Number one easiest upgrade to do... Go from the 13/16" master cylinder to the 15/16" master cylinder... Pedal is nice and firm and provides better control. I personally have converted it on all 5 of my 88-91' Honda's that didn't already have it. Slap it on, bleed the brakes, stop on a dime... well maybe not the last one but you get the point.

If you need to know why I can give you the formulas on how/why it works by increasing the bore a measely 1/8"...

 

I forgot to mention the 5 biggest reasons for 90-91' Civic EX Master Cylinder: 1/8" bigger than smaller bore master cylinder, bolts right up to any 88-91' Civic/CRX brake booster, brake line sizes and angles same as factory, brake light wires have same plugs and lengths, and bigger fluid resivoir for current or future upgrades.

 

just changed out the 3030 valve for a 4040 valve and replaced the 13/16 mc with the 15/16 mc...waiting on the vato loco to get home to help me bleed the brakes now since the pedal just drops to the floor with no pressure...didn't bench bleed the mc but im gonna bleed them the old fashioned way anyways...!!!

 

I regret to inform you that you MUST do some type of "bench bleeding"... be it in the car or on the bench. The goal is only to push the piston in around 1/2" or something like that... You must reroute the plastic tubes or what have you to the resivoir or separate container (easiest to resivoir so you don't have to keep refilling it). If you do not feel like messing with that then I suggest still only pressing the pedal a small amount and having all 4 bleeders open at the same time... Air in the master cylinder may as well be a bad master cylinder.

BiG_ChOr!Zo do you have a rear disk swap? If not, I personally would leave your 30/30 or what have you in there... to each his own though... let me know how it works out with a 40/40 if you have drums - I am curious as I have never done that due to fear of premature failure of the shoes.

 

i have full discs, 4040 but no 15/15 MC
pedal is soft. can't wait to stop on dimes. or to pick up tha dimes :D

 

just finished bleeding all four corners by having someone pump the brake pedal and me opening up the bleeder screws individually...didn't bench bleed the mc either but i sure did get all the air our of the system by the above mentioned method and the beast stops on a dime...i pumped and opened up the bleeder screw 6 times on each caliper.

im running a 90-91 civic ex master cylinder on a stock oem lx 13/16 brake booster with a 4040 valve and a rear disk conversion...no leaks whatsoever and my brake pedal doesn't sink to the floor anymore...test drive proved results.

score another victory for the salami monster

 

Oh, I didn't know you were four wheel disk... Then yes, obviously you had to have the 40/40... glad to hear you are firm again... ;-)

 

Good to know thanks chor!zo... mine doesn't sink to the floor its just soft not are rock hard like it should be im ordering a ex MC as we speak... hoping for good results. Any setups on in car MC bleeding setups?? pics maybe?

 

wait! I read it wrong... i thought you use your stock civic booster... and a ex 15/16 MC?? This one im looking at says 13.16

 

http://www.tegger.com/hondafaq/maste...hbleeding.html

There ya go..

 

^Thanks, have been looking for that myself!

 

You read what wrong? Do as I say... a 90-91' Civic EX master cylinder is 15/16" and will bolt right in place of a 13/16" master cylinder with OUT having to change a thing... what's the problem? I stated all this previously...

 

I was reading it all wrong... the ex MC i found on ebay supposuvly says 13/16... Ill keep my eye out. thanks guys