serious brake question

[boris]

I've finally got my project up and running but front brakes are not happy now I have 6 piston calipers from the 95 frame I bought but had no master cylinder so have used my 90 4 piston master cylinder has anyone done this or can anyone shed some light on whether this is not a happy partnership maybe bigger bore needed for the 6 piston set-up or should this work and my calipers need re-kitting thnx anyone with insight

[Seifer]

What's the punchline?

[miniman1]

So this is a serious question???

Ive never had a problem with mixing m/c's and different calipers, but what do u mean 'they aren't happy'????

Maybe u should try re-posting this in the appropriate area.

[davio]

it is possible to have probs with cross matched set ups ,but it usually applies to 70s masters , they dont move enough fluid for modern calipers , but i cant see that bein ur prob , more likely air in the lines or sticky pistons , as above ,, what are ur symptoms?

[Tony OW31]

A different diameter master cylinder will give a different feel to the lever, either a wooden feel, or spongey back to the bars feel, calipers are usually matched to a master cylinder piston size, as long as you get one with the correct diameter it will feel right, the make wont matter.

[TurboKat]

Generally speaking most twin 4 piston caliper setups use a 14mm bore master cylinder & 6 piston setups use a 5/8" bore, you can alternate between the 2 m/cyl sizes on either setup & you'll feel fuck all difference - eg, the 14mm m/cyl mated to a pair of 6 pots will have a firmer lever feel requiring slightly more lever pressure than the 5/8".
Obviously, it's best to use matched sets but you won't go headfirst into the back of a truck if you don't.

[boris]

thanks all sorry I put this in the wrong area still learning the forum demeanor but seems the mc pistons are around the same diameter will try taking mc off tomorrow and bleeding seperately