Kurt,
I found this site from Wildwood that explains it pretty well:

http://www.wilwood.com/MasterCylinders/MasterCylinderValves.aspx

Apparently the RPVs are required when the MC is below the horizontal plane of the calipers and maintain the right fluid pressure (eliminate reverse flow to the reservoir)for correct pedal response.

I had forgotten the specifics, but can remember I needed these for my under cab Master cylinder, Disc/ Drum set up. I also remember all the fun of bending the brake lines. Very Satisfying.

good luck
Tim


Last edited by Olblue3600; 09/12/2012 11:15 PM. Reason: addition info added
1950 Chevy 3600


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