master cylinder for ls1 brakes

[TMat]

Hi,
New to the site, hoping you can help out. I have a 69 camaro with factory original front discs. I have a pair of ls1 calipers and rotors, and want to know if I have to change the master cylinder or can I use my existing master with these calipers. Any help would be appreciated.

Thanks
Trevor

[chevymike]

I am hoping someone can answer this as I have asked twice in the past with no replies. I was going to keep the stock drums in the rear for the time being but swap the factory discs over to the LS1 calipers/rotors that I have. I think my current MC is 1 1/8" with booster.

Can anyone help us out??? Thanks :D

[Railing68]

Well I think I can answer the first part. I am running stock fronts with pbr rears currently with stock disc drum master. But with PBR fronts the bore size should be 1" with power. I don't think you should try the 1 1/8, not enough pressure for PBRs. I will have the fronts converted within the next month. I am using 12x1.25 Baer eradispeeds and 98-02 Fbody LS1 calipers with 93-7 rears. So I think 1" should be right and the pbr rears are approximately the same bore size as a drum wheel cylinder. So I know stock master will work with rear pbrs, not sure if ls1 rears differ in size. If someone knows better please correct me. The other thing is if someone knows a source for the 1" power master cyl? SS

[Tom Welch]

check out Dave Pozzi's tech page.

[TMat]

David, If you are reading this can you give me some more info please. Thanks

Trevor

[Railing68]

Spoke to Baer today,my prior research shows the ls1 camaro master cyl, is a 1" bore. I will be using the 75 caprice master which is disc/drum, can be used either way (disc/disc). Are you looking for power or manual? SS

[Blue70]

I used a 1968-1976 Corvette manual four-wheel disc-brake master cylinder (GM part No. 18001118) after reading THIS aritcle

Driveway testing checks out OK ..........but, I will not be able to put it on the road and give you my final thoughts untill I get back from vacation around June 11th

[TMat]

The only thing is I want to keep my rear drums for now and just use the ls1 setup on the front with my existing master cylinder. I am going to wait on rear discs for now. Will my existing master cyliner be adequate for the ls1 calipers?


Trevor

[Railing68]

not at 1" 1/8 you will need 1" or it will be hard to push. You will need to change, corvette for manual 15/16 or 1" for power maybe even 15/16. But 1" is stock ls1 98-02. SS