I have a 91 Civic SI. I am in the middle of converting the rear brakes to disk brakes. What brake lines am I supposed to use?

 

You can reuse the SI rear brake lines. I have read up multiple posts that confirm this. I can't wait to do my rear disk brake swap in the spring! did you upgrade the brake master cylinder, booster, prop valve, and front disks? I have read somewhere that si civics came with a 4040 prop valve but i am leery. I put in a DA prop valve just to be sure but it looked identical to the Si one.

 

I should have said brake hose, not brake line. The Si brake hose is clearly much too short. I have the hoses off the Integra that donated the trailing arms. They might work but now I have a question about the brake calipers that I need to resolve first. I will be posting that question after I take a few pictures.

 

Use the brake hose that corresponds with the disc brake caliper. Either a 90-00 Integra, 90-91 CRX, or even the del sol should work.

 

Isn't a 1991 SI supposed to have rear discs from the factory?

 

CRX yes, Civic no.

 

This. When doing this swap on my sedan, I used DA ss brake lines and the DA emergency brake cables

 

If you just order 91 CRX stainless steel mesh hoses it'll work.