I just replaced the master cylinder on my 89 Civic Si with a rear disc swap from a 92 Integra. The old one was the worn out stock 13/16" cylinder. It was replaced with a brand new 90 Civic Ex 15/16" cylinder. Now, the old master cylinder was really worn out to where it would slowly go to the floor when I sat at a stoplight.

After I installed it, I took it for a test drive. The pedal feel was pretty good. It could probably use a full bleed at all corners. The car stopped pretty well. But I couldn't lock up the wheels at all. I tried a few good times from about 40-45mph and they just wouldn't lock up on dry pavement. The car also had 15" Rotas with Dunlop SP 9000 195/50/15 tire on them. Any reasons why I couldn't lock up the brakes?

 

When did you do the swap?

There is some physics behind why they wont lock up, but I'm nto sure if thats the case....15/16" vs 13/16" shouldnt make a difference...but in anycase.

bigger diameter isnt allways better, a larger diameter will require you to press the pedal harder but for a shorter distance than a smaller diameter will (for the same braking)

 

did you change the prop. valve ? I did this swap with my car, but didn't do the MC and brake booster.. I'm going to locate an ITR MC and booster and put it on.. yeah I know it might not bolt right up.. but I don't have a problem drilling holes in the firewall to bolt it onto the car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sicivic &raquo;</TD></TR><TR><TD CLASS="quote"> It could probably use a full bleed at all corners. </TD></TR></TABLE>

BTW how much did u pay for the new 1?

 

I got a Nisin 90 Civic Ex for $90 but I got it at cost thru. the shop I work at.

Where exactly is the prop. valve?

 

Its usually located on the passenger side if I'm not mistaken. It looks like a little cylender with allot of brake lines gooing to it.

If you didnt change the prop valve during the swap, this could be a source of your problem. Hence why I asked if you had just done the swap.

 

it's on the passenger side of the car.. it has 2 lines coming in from the master cylinder and 4 lines going out of the prop. valve. all lines are hard lines.