i got a 91 civic si and i assume my master cylinder is the "0.937in bore" is that true? also what would happen if i used one for a 1.5l hatch/sedan?

autozone says 1.6 is the 0.937in and the 1.5 is 0.812in?

curious because im tight on cash and autozone wants $50+$20core charge on the 0.937in (and its a refab) but the 0.812in is $30+$20core charge for refab and only $50 for brand new w/o a core charge!

 

By using the smaller MC, you will have to push the pedal down a little further to get the same braking power.

 

Why don't you just buy a MC repair kit(rebuild kit) for $30.Good time to bleed the system with new fluid.

Remember you're going down 2 sizes if you swap to the smaller MC.

 

my car has a 13/16 on it but the autozone comp said i needed a 15/16 and that aint right, the .937 is 15/16".

 

why not check the vin and go with that

 

everwhere i looked said a 91 civic SI came factory with the 13/16 but autozone and advanced say 15/16. i went ahead and got the 13/16 because it was $30 cheaper brand new then the 15/16 refab.

working good.

plus everywhere i look says switch to the 15/16 if you do a rear disk swap. or you gota change the whole brake booster.

anyone know what proportioning valve i have on a 91 si?

 

Some do list it as a 15/16.When you switch to rear disc you'll need to change out the proportioning valve(PV) to a 4 whl disc PV(number 40-40 I think).

 

the only car that came factory (88-91 civic/crx) with a 15/16 MC was the 90-91 Civic EX. the 88-91 SI models came with the 13/16. mainly due in fact because the EX had the bigger front brakes (10.1" rotors and matching brake pads).

if you have an SI ask for the 13/16 master cylinder. if you need a part number lmk

 

Rebuild kits are typically not a good idea. Usually the cylinder bore gets corroded which is what causes the master cylinder to fail in the first place. A replacement is the better way to go and ends up being cheaper/easier to install...

 

Autozone's Database is wrong about 90% of the time. Check your stock MC and see what it says on the passengers side (just bellow the reservoir).

The 88-91 Civic Si has the typical 13/16" MC (.8125"), small 9.4" Akebono/AM front discs, and rear drum brakes.

The 90-91 CRX Si has a 7/8" master cylinder (.875"). Currently the same part number as the 93-95 EX coupe (non abs) and 94 Del Sol VTEC (non ABS). It's also the same as all the 88-91 4WD Civic Wagons. I know because I've been working on a EG Coupe brake swap for my 94 CX and all I need now is a new master cylinder.

The OEM 7/8" master looks just like the 13/16 except it has a BLUE tinted reservoir. You can currently buy a brand new Nissin/OEM 7/8" for $108 shipped from carpartsdiscount.com (look for a -5% off coupon). Also, Hondapartsnow has them for $117. Autozone sells the reman-unit for $32 (+$20 core) or you can buy the rebuild kit and hopefully make that work. The Nissin 13/16 should be found for considerably less because there are SO many Honda's that use them.

7/8" MC should be used with 56mm front caliper pistons.

http://www.carpartsdiscount.com/auto...tml?3593=83787



The 15/16" MC can be identified by it's oversized reservoir. This MC should only be used with Integra front calipers, or Civic ABS front cailpers (same as Integra w/ 57mm pistons).



All other Civics & CRX use the 13/16" MC.

 

Yay for correct information! I edited this to because you fixed it...

 

Yeah yeah, I double checked that after I posted it and came back to edit. +3 Internets for you! Somebody get this man a cookie!

***Edited post above.

 

Everybody is allowed to have a brain fart now and again, as long as it gets corrected. Lord knows I have mine at my old age...

 

 

alright alright alright, the 91 CRX SI has disk brakes on the rear, and i belive the 15/16 MC is for that (and others too) but a 91 CIVIC SI has drum brakes on the rear and a 13/16 MC. correct????

 

You need to reread everything that has been written... Your answer is above... Already all typed out for you...

 

Actually this guy is correct according to the parts list on Hondapartsnow. 13/16 MC, rear drums, Akebono AM 9.4" front discs for the CIVIC Si. I will amend my previous post again... Doh!