its a 91 4 door i did the front brake pads and rotors and noticed that one caliper was leaking so i rebuilt both of them now sometimes the brake pedal will go do the floor. not fast like a big leak but slow and i got give it alot of pressure. there is no leaks on the floor and the fluid is still full. so is my master cylinder shot? or should i try bleading it some more??

 

the master is probably on the way out.

 

you might be leaking may be the brake line or maybe you dont have brake fluid

 

when my car was doing that it turned out to be the MC on the way out.

 

It's the seals in the master cylinder. It's actually advised not to push the brake pedal all the way to the floor because you'll push the seals into that "unused" section of the cylinder where the crap accumulates.

Once those seals get expletiveed, they'll never get better. Honda does not rebuild master cyl's, so get a new one.

 

sounds good guess its time to upgrade to the prelude one. thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zcmotor &raquo;</TD></TR><TR><TD CLASS="quote">you might be leaking may be the brake line or maybe you dont have brake fluid</TD></TR></TABLE>

-----&gt;

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by black0hatch &raquo;</TD></TR><TR><TD CLASS="quote">there is no leaks on the floor and the fluid is still full.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by black0hatch &raquo;</TD></TR><TR><TD CLASS="quote">sounds good guess its time to upgrade to the prelude one. thanks </TD></TR></TABLE>

Prelude one? I've never heard of that.

 

ya 89 prelude has a 15/16 master cylinder bolts right up just gota slightly bend one line very easy did it to a crx i had before.

 

The integra MC/booster bolts righ up also!

 

this is true but im not trying to buy a booster too. the prelude mc bolt right up to the civic booster.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by black0hatch &raquo;</TD></TR><TR><TD CLASS="quote">ya 89 prelude has a 15/16 master cylinder bolts right up just gota slightly bend one line very easy did it to a crx i had before. </TD></TR></TABLE>
Or you could just get the '90-91 Civic EX 15/16" master cylinder that already has the fitting bores oriented at the proper angles so you don't have to bend any lines . . .

You really shouldn't use a 15/16" master cylinder with stock DX/LX calipers; it's difficult to modulate the pedal. The 7/8" MC from a '90-91 CRX Si or '93-95 EX 2dr non-ABS is more ideal.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Targa250R &raquo;</TD></TR><TR><TD CLASS="quote">

You really shouldn't use a 15/16" master cylinder with stock DX/LX calipers; it's difficult to modulate the pedal.</TD></TR></TABLE>

Why's that? Not that i'm trying to prove you wrong, just trying to learn something.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ~sp33~ &raquo;</TD></TR><TR><TD CLASS="quote">Why's that? Not that i'm trying to prove you wrong, just trying to learn something.</TD></TR></TABLE>
Because I've done it, and it was more difficult to modulate the pedal - you know, like I just said it was.

 

what do you mean by "modulate the pedal"?? ive done it before to my old crx and it seemed to brake better in my opinion.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by black0hatch &raquo;</TD></TR><TR><TD CLASS="quote">what do you mean by "modulate the pedal"??</TD></TR></TABLE>
mod·u·late (mj-lt)
v. mod·u·lat·ed, mod·u·lat·ing, mod·u·lates
v.tr.
1. To adjust or adapt to a certain proportion; regulate or temper.
2. To change or vary the pitch, intensity, or tone of (one's voice or a musical instrument, for example)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">ive done it before to my old crx and it seemed to brake better in my opinion.</TD></TR></TABLE>
Look, I can tell that you really don't know what's going on here. Changing the proportions of the hydraulic system does not improve braking, no matter what you may be thinking. All it changes is the pedal feel. Braking distances will be exactly the same at the threshold of grip no matter whether the pedal travel is one inch or eight inches - it's simply easier to modulate the pedal to stay on that threshold when you have more pedal stroke to vary the pressure at the calipers or wheel cylinders and avoid lockup.

The smaller the caliper pistons, the smaller master diameter you need in order to keep a reasonable pedal stroke. A 15/16" master cylinder is meant to be used with 17CL14VN calipers, and I wouldn't recommend using it with anything less than 16CL14VN or 16CL13VN calipers (both of which are paired with a 7/8" master from the factory). The small 20xx-casting calipers are meant to be used with a 13/16" master and shouldn't be used with one larger than 7/8".

What year and trim was your "old CRX"?

 

ok weve established that im not as smart as you i still dont understand the whole modulate thing but oh well thats just you trying to sound better then me but i dont care. you probably are better then me. the crx i did it to was a 88 crx dx. it really didnt stop it better its just that the pedal felt better. probably becuase it was leaking before too. im not saying you wrong just saying tons of people do it with no problems. so this thread can die now i dont want to start an internet fight with someone i will never know. thanks for all the other input.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by black0hatch &raquo;</TD></TR><TR><TD CLASS="quote">ok weve established that im not as smart as you i still dont understand the whole modulate thing but oh well thats just you trying to sound better then me but i dont care. you probably are better then me. the crx i did it to was a 88 crx dx. it really didnt stop it better its just that the pedal felt better. probably becuase it was leaking before too. im not saying you wrong just saying tons of people do it with no problems. so this thread can die now i dont want to start an internet fight with someone i will never know. thanks for all the other input.</TD></TR></TABLE>

Bigger Master Cylinder = Shorter pedal travel with more actual force required to operate brakes.

Smaller Master Cylinder = Longer pedal travel with less actual force required to operate brakes.

With too large of a master cylinder, the difference between mild braking and full force braking, can be within too small of a range on the pedal travel, making it difficult to properly Modulate (Control) the brakes.