[jcarter]

Has anybody used one of these on a disc brake conversion?How do you remove the plastic resevoir?The one I was looking at using leaned back on the firewall, so was wanting to use a different res. from a flat firewall vehicle, or do reman one's come with the res. mounted? I was looking at using one off of an 84 Caprice which has a bore of about 1.6 " on the booster end.I have an 84 S10 one that measerses 1.45 " at booster and has flat firewall resevoir. I think the smaller one is big enough , compared to the size of the origional, 1957 buick, but maybe not?Any advise would be helpfull, and I have already read all the tech advise at MPBRAKES which has also helped some.

[Restore60s]

I would think the S-10 Master Cylinder would be sufficent. The re-man's come complete. If you are wanting to switch fluid reservoirs I think the body mounting seals come in a re-build kit. Or at least they used to. Why not just get a re-man with the reservoir you are looking for. I would make sure that it fits the booster bore & works freely before filling it with fluid. I have seen a S-10 set-up on a 39 Pontiac, so I'm assuming you should not have any problems.

[jcarter]

Thanks,I checked with a couple of suppliers and found that you can get it with a resevoir or without. I am going to use an S10 setup on my 39 Chevy, but was setting this up for a 57 Buick, and was wondering if I may need a bigger m.c. because of the heavier car?Have since found a Chevy 1/2 ton m.c. same size as the Caprice, but with a resevoir for a flat firewall.

[tomslik]

you'd use a smaller bore m/c to get more pressure but you'll have to have more travel to move the same amount of fluid.

[Triaged]

s10 MC is 15/16" bore
1/2-ton/caprice is 1-1/8" bore

All the aluminum MC's with pastic res. are what is called a "step bore" or a "quick take-up" MC. They used these with calipers that would retract the pistons. The larger bore on the MC would be used to take up the gap and it would then transfer over to the smaller bore.

Because of this I don't think you would end up with too much peddle travel even if you used the smaller s10 MC.

FWIW f-bodies used the same MC's but the brake lines come off on the passanger side to clear the strut mount. I think they are 1-1/8" as well but I'm not sure.

I think 83 was the start year for these MC's and some time in the early 90's they went to a metric bouble flare.