Brake Master Cylinder Built In Proportioning Valve

  • #1

    Brake Master Cylinder Built In Proportioning Valve

    This topic isn't very common but some of you out there like to tinker and may have beat me to this so I'll ask before I dive in myself:
    On the end of the MC is another smaller cyl next to the rear brake output with a plug. I assume the factory adjusted prop valve is under there…
    Has anybody popped one open and played with this?

    I'd like to imagine there is some sort of screw with sealed threads under there that can potentially be used to increase or decrease the rear proportioning.
    10:1 VG33E Swap 200HP
    M30 ECU with N60 MAF
    Pathfinder Intake, Euro Cams, Russ Cam Gears, Headers and Gibson Cat Back
  • #2
    I've opened one, haven't played with it. On my Jeep when I went from disc / drum to all disc, I messed with the prop valve on it (which is separate from the m/c) and the difference was in the springs.
    Here's what's under the little plate and hex.

    and here's upper and lower.
    Last edited by Dunkine; 09-03-2017, 11:01 AM.
  • #3
    Very interesting, I imagine varying that spring pressure on the little valve would be a way to adjust the split point for the rear braking…
    I may end up playing with that of my rear bias is not right with my next brake setup.
    10:1 VG33E Swap 200HP
    M30 ECU with N60 MAF
    Pathfinder Intake, Euro Cams, Russ Cam Gears, Headers and Gibson Cat Back