Master cylinder for 4 wheel disc swap?

Discussion in 'Suspension, Steering, Brake & Wheel Topics' started by CarNDrvr, May 10, 2009.

  1. CarNDrvr

    CarNDrvr Veteran Member

    897
    0
    Feb 25, 2003
    Gainesville, VA
    Well, I bought a Wilwood master cylinder that they recommended to go with my 4 wheel disc conversion. It bolted up, but the pedal was mush until about 3" of travel. After talking with people who have been through this same ordeal, I was told to get a factory 4 wheel disc brake master cylinder. I ended up getting a 1979 Trans Am master cylinder for a 4 wheel disc brake car. My question is, should this one work for the Wilwood upgrade? It bolts right up like the old stock one. I know the stock disc/drum master doesn't work because of something about the rear brake amount of flow or something like that. Will the stock 4 wheel disc master cylinder disperse the fluid correctly for this application? Wilwood also mentioned a '71 Corvette master cylinder because of the fluid distribution also, but it doesn't bolt up. That's why I went with the T/A one.
     
  2. gregh

    gregh Moderator Staff Member Lifetime Gold Member

    As far as I know, you'll need the TA disc brake proportioning valve too or you can get an aftermarket adjustable valve.
    Otherwise, you won't be getting enough fluid to the back brakes to make them work properly.
     
  3. BLUE72CAMARO

    BLUE72CAMARO Veteran Member Lifetime Gold Member

    4,443
    59
    Mar 15, 2004
    Bunker Hill, IL
    You will need a different proportioning valve for sure. Should be any reason the wilwood master wouldnt work mine is rock solid on my car with a disk/disk prop. valve.
     
  4. woody80z28

    woody80z28 Veteran Member Lifetime Gold Member

    5,430
    12
    Sep 8, 2004
    walton, ny usa
    The 71 Vette master should bolt up and work, that's the one I'm using.
     
  5. CarNDrvr

    CarNDrvr Veteran Member

    897
    0
    Feb 25, 2003
    Gainesville, VA
    I'm eliminating the stock proportioning valve as per Wilwood's recommendation. They said it should go from the master to the front caliper with nothing in between. The rear should go from the master to the Wilwood prop. valve to the calipers. I have a Wilwood rear prop. valve inline already, but it comes before the stock prop valve.

    Blue72...what exactly is your set up? Did you have to play with brake pedal rod position? Did you just bolt up the wilwood master to your brake booster while utilizing the stock rod? The said it may need adjusting to get rid of the 3" of dead pedal.
     
  6. BLUE72CAMARO

    BLUE72CAMARO Veteran Member Lifetime Gold Member

    4,443
    59
    Mar 15, 2004
    Bunker Hill, IL
    Well my set up in a nutshell is hydraboost with wilwood master then into a factory disk/disk prop. valve. If I need to adjust the bias more I will install an adjustable one further down stream. But I did not have to play with rod length at all on mine just put in the little spacer bushing that came with master and installed it.
     

Share This Page