Wilwood Master Cylinders

[binzagr]

Hello,
I have a Wilwood upgraded brake system. I received 2 master cylinders with different bore sizes is that normal? If yes, which one is for the front and which is for the back.

[Papa]

The larger 0.75 is for the front.

[binzagr]

The larger 0.75 is for the front.

The Reason I’m asking because I have build up pressure problem in my rear brake master cylinder which is the small size .625 .In the catalog picture show both master cylinder .75

[2bking]

The Reason I’m asking because I have build up pressure problem in my rear brake master cylinder which is the small size .625 .In the catalog picture show both master cylinder .75

Most likely the problem is with the adjustment of the pump rod length where the piston inside the master cylinder isn't returning to the full out position thus the bleed off hole inside the cylinder isn't being uncovered. Check to see if the rod is loose with the pedal full out. If not, adjust the rod length until there is slight play with the brakes released.