i need a bigger master cylinder

[gasman]

ive got an ae92 fxgt and it had ae92 gtz front calipers and the brake pedal was fine and had a nice firm feeling. i got hold of some twin pot calipers off and ae101 super strut gtz and put them on and the pedel was soft no matter how much i bleed the system.
i found that one of the sliding pins were seized and trying to work it lose i snapped it so i found some cheap front single piston calipers off an st206 curren and upon closer comparison of the 3 calipers i found that the piston area of the twin pot calipers is actually smaller than the ae92 gtz ones (both around 1800mm squared) and the st206 ones are around 2200mm squared so i decided to run them.

so now my problem is that the stock master cylinder is too small (or at least i think so) and the pedal is still quite soft unless you jab on the pedal real fast then it will be had but sink down soon after. is this a symptom of a faulty master clyinder? if so how could it of busted it self in the short time when i was replacing my calipers? or is this because my master clyinder is too small? if so what larger master cylinder will fit?

thanks in advance
Justin

[gasman]

bump

[punter]

What you're describing sounds like a dodgy master cylinder.
I've got 2 ae101's one superstrut and one not, they have the same master cylinder, so I don't think size is you issue.