Keep this MC???

[firehawk408]

I have a 73 firebird with C5 frt. brakes and 80 trans am WS6 rear disc brakes. I have a master cylinder from a 80 trans am WS6. I used this master with the rear disc brakes and stock 2nd gen disc brakes. It seemed to work okay. Since swapping over to the C5 brakes I haven't driven the car again. Started a long restore process. From the research I've done a 1 1/8 MC is recommended for this setup and I believe that is what this MC is. My question is, before I could even get my car running with the new brakes I notcied this leak where the MC meets the Booster, should I repair this leak and continue on or replace the MC all and all because it is not correct for this combo? Thanks for the help, I know this "finding the right MC" question has been beaten to death but I just couldn't come up with an answer doing a search.

[Apogee]

Your MC is leaking, so that means that at least a new one is in order. I think you'll find that the 1-1/8 bore MC is going to be on the large side now that you have effectively reduced your overall piston area up front by switching to the C5 calipers. If you've got really good vacuum levels, it could work out okay. If not, it'll be a hard pedal and difficult to generate enough pressure to get the C5's to function like they should. I'd look at stepping down to either a 1" or 1-1/16" bore MC at most...or stepping up to hydroboost if the budget allows, in which case the larger MC would work fine.

Tobin
KORE3