Perhaps my master cylinder is bad?

[1993 CB7 LX]

so, i replaced a brake line and caliper on my ex in the rear. the line i replced was the little metal section. i bled the brakes and they work fine, except for the fact that my pedal almost goes to the floor. when i pump them, it a little better, but still squishy. when the car is not running, the pedal builds pressure, but not when its running. could it be my master cylinder?

[C91BLX7]

Was it like this before?

You might need to bleed it better and try bleeding all the wheels.

[1993 CB7 LX]

the pedal has been squishy since ive had it, but not near this bad. ive thought that too, i guess ill try bleeding all 4 tomorrow

[Losiracer2]

Did you let the fluid level drop in the master when you changed out that line? if so then you might need to re bench bleed the master before you bleed the brake lines

[1993 CB7 LX]

the fluid was low and i topped it off then bled. how do i bleed the master?

[Losiracer2]

the fluid was low and i topped it off then bled. how do i bleed the master?

you have to bench bleed it, its done off the car usually. When I bought a new one, they included some barbed fittings that threaded into the ports and then some clear vacuum tubing that you loop back into the master to get all the air bubbles out.

[1993 CB7 LX]

shit, sounds like a lot of fun haha. so how would i do it to my old one? or should i just buy a new one?

[dhill_cb7]

When I bled my master cylinder I threw it on a vise. As stated before it should come with two tubes. You attach the tubes to the open ports and loop them back up to top of brake master cylinder.

Here is a video that "eric the car guy" did. http://www.youtube.com/watch?v=trotrlIG2sk

[1993 CB7 LX]

thank you very much man. doesnt look so bad now that i see it being done

[accordztech]

I personally never bench bled a BMC.

But yes you got air, bleed your brakes.