84 Sn95 brake swap, wilwood master cylinder issues.

[Byers]

I have swapped my 84 capri over to SN95 brakes, calipers front and rear. Using sn95 booster with a Wilwood tandem 1 inch bore master cylinder, and in line proportioning valve.

While trying to bleed brakes, The rear bleed fine. But when you move to the front they do not bleed properly. The best way to explain it is the pedal is firm about half way off of the floor. When you bleed the rears the pedal goes to the floor like it's supposed to. When you bleed the front brakes, a small amount of fluid comes out and then stops, and the pedal does not move at all. Originally I thought it was in issue with my line lock, but when I began cracking lines with pressure held onto the pedal removing lines the whole way to the outlet on the MC the pedal did not fall, just stayed half way up.

I then realized I had the lines backwards between front and rear (big resivour and small) So I switched them and the only thing that did was switch the problem to the rear.

I know the piston bottoms in the bore before the pedal hits the floor. The pushood also isn't holding the piston in at all. I bench bleed the heck out of the thing but I'm still not sure if I completely got all of the air out of it.

Just wondering if anyone has had similar experiences or If it could possibly be a defective master cylinder.

[Byers]

After bench bleeding the master cylinder (on the car) again. I plugged both ports on the cylinder and the cylinder completely hydrolocks. I gravity bled, vaccum bled, and normally bled the brakes multiple times. Without the engine running I do have some pedal, about half. With the engine running the pedal is still completly soft and I can feel it bottom in the master cylinder. The car has all new sn95 v6/gt calipers, rotors and booster. The wilwood master cylinder is a 1 inch bore, while a stock one is 1 1/8 bore I think. Would that make that much of a diffrence in pedal feel/effort? Thanks

[dagenham]

I believe you just answered your own question. The smaller bore isn't enough to move the proper amount of fluid. Especially if the pushrod is a different length than stock.
Side note question. Why did you choose a smaller bore mc instead of using a sn95 mc to begin with??