HELP - Brake Master Cylinder

[ACCORDing2R]

So after 360,000km my brake master cylinder finally went... I went to the local parts place and found one for $108 CDN. The thing is, they offer 3 different ones. One is for non-ABS CB7's, and two others for ABS (EX, SE) models. The two ABS ones are 15/16" and 1". Visually they look the same, with the exception of one being a little bigger in diameter. I dunno which one to buy and don't wanna take it appart just to find out... I'd rather do it all at once when I buy it.
The car is a 92 EX-R (EX in USA) with ABS.
PS. Anyone know what the seal is called that goes between the master and the booster?? I might as well replace that too while I'm at it.
Thanks!

[YK86]

The seal between the master cylinder and booster is called the rod seal (part number 46185-SEO-003). Roughly $3 CAD.

As for the master cylinder, I looked up a few sites like Altrom Canada and Honda and they all list the rear disk cb7's abs and non as using the same one. So the both 91 and 93 SE's with or without abs and EXR's with abs have the same part number. That comes up as part number 46100-SM4-G54. The drum brake ones are listed as 46100-SM4-A04. If the auto store you go to is like mine (I live in canada as well), they should be able to cross reference and find the perfect matching using the oem part number. Is there any markings on your master cylinder? That might help as well. If worst comes to worst, use a caliper gauge to measure your diameter and grab the one of the two that has the same diameter.

[ACCORDing2R]

Thanks for that input YK86. What I found out today is that if you upgrade your brakes, chances are you're gonna need a larger master anyway. I didn't check which one I have stock yet, but I'm gonna go with the 1". Since my front rotors are bigger diameter and my calipers are larger I might as well upgrade the master.
I dunno to what extent this is true... but someone told me today that if you bleed your brakes with the master cylinder (fluid resorvoir) cap open... that can suck in air and fawk it up. I bled my brakes many times before with the cap open, just adding more fluid as it goes down and never had a problem.
Has anyone heard of anything like this?? That you have to close the cap as you're pumping the pedal??
Also... I want to verify the proper order of bleeding brakes on a CB7. I know most Hondas are different. The order on Type R brakes is different from that of a GS-R. 1. Rear-pass. 2. rear-driver 3. front-pass. 4. front-driver ??

[YK86]

I think leaving the cap open is only bad if you don't top up the fluid while bleeding. But you mentioned you do that so that shouldn't be an issue. Since you are changing the master, I'd get a big bottle of fluid and make sure all the air is out. The reservoir goes down fast even after a couple pumps so just make sure you always have fluid in there along with a big bottle of brake oil as you'll probably use alot since you're changing the master.

As for the order (someone correct me if I'm wrong), it should be
1-passenger rear
2-driver front
3-driver rear
4-passenger front

[clarksterdotcom]

As for the order (someone correct me if I'm wrong), it should be
1-passenger rear
2-driver front
3-driver rear
4-passenger front

dead on the money..my question is this. i havent had a chance to do anything to my brakes but every once in a while after some spirited driving the brake pedal loses sitffness and drops to the floor. i thought that this would be just some air in the line due to the fact it only happens once and a while. while i have been told by a "wannabe" mechanic that it is my brake master cylinder. which do you guys think it is..just for infos sake

[YK86]

It very well maybe the master showings signs of going out but then again, I'm also a hobby mechanic. My friend with a 92 Accord also described what you said 2 years ago. Just once in a while, the pedal would sink to the floor. But his car only had 100K and it wouldn't do it very often or when I was with him so he shrugged it off. Early this year, the master cylinder blew.

[ACCORDing2R]

dead on the money..my question is this. i havent had a chance to do anything to my brakes but every once in a while after some spirited driving the brake pedal loses sitffness and drops to the floor. i thought that this would be just some air in the line due to the fact it only happens once and a while. while i have been told by a "wannabe" mechanic that it is my brake master cylinder. which do you guys think it is..just for infos sake

You mentioned this happens "after some spirited driving". When I had stock rotors my spirited driving overheated my rotors at times, and the brakes faded after prolonged abuse. The pedal went further to the floor and felt mooshy, and my master was fine for a long time. But it could be that on your car it's giving you a warning who knows..

Anyhow i changed my master today, bled it, bled all four calipers. Car stops on a dime. Fluid never looked cleaner.
Thanks you everyone for your input!

[clarksterdotcom]

You mentioned this happens "after some spirited driving". When I had stock rotors my spirited driving overheated my rotors at times, and the brakes faded after prolonged abuse. The pedal went further to the floor and felt mooshy, and my master was fine for a long time. But it could be that on your car it's giving you a warning who knows..

Anyhow i changed my master today, bled it, bled all four calipers. Car stops on a dime. Fluid never looked cleaner.
Thanks you everyone for your input!

yea well i bought a BMC and of course am going to bleed the system. just wondered if i was correct in my assumptions..

and yea i drive hard a lot of the time because i have so much fun stuff telling me what to do...

4bidden short shifter saying, "short throws= harder shifts"
razo shift light saying," look the RPM's are climbing SHIFT!!!"
MOMO sttering wheel saying," ooOOOooOOoo leather..touch me and take turns with confidence!"

[ACCORDing2R]

yea well i bought a BMC and of course am going to bleed the system. just wondered if i was correct in my assumptions..

and yea i drive hard a lot of the time because i have so much fun stuff telling me what to do...

4bidden short shifter saying, "short throws= harder shifts"
razo shift light saying," look the RPM's are climbing SHIFT!!!"
MOMO sttering wheel saying," ooOOOooOOoo leather..touch me and take turns with confidence!"

LOL! That's funny dude.
I feel like that too when I drive. I feel like hitting VTEC in every gear.
Upgrade to a larger diameter rotors (preferably slotted ones), and bigger calipers. I did that, and now you have to try extra hard to overheat them.