Bolt in 15/16 master?

Discussion in 'Suspension, Steering, Brake & Wheel Topics' started by Zedzag, May 9, 2009.

  1. Zedzag

    Zedzag Veteran Member

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    Anyone know of a GM 16/16" master cyliner that will bolt in to my 81Z? I need one that has metric fitting just like the factory 81 master. This is for my C4 style baer track kit.
     
  2. Tito

    Tito New Member

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    I'm pretty sure '81 still uses the english fitting sizes of 1/2-20 and 9/16-18

    '81 picked up the "quick-takeup" style master with the larger 3rd/rear piston though, which are specified with metric bore diameters...

    I can't guarantee it, but the '88 S-10 master cyl is a 24mm bore (~15/16") and should bolt right up with the same 1/2-20 and 9/16-18 fittings on the driver's side of the master. You'll probably need to swap the plastic reservoir from your old master to the new one to keep the angle right...

    -T
     
  3. Zedzag

    Zedzag Veteran Member

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    I thought the fittings would be metric. Cool. How hard is it to swap out the reservoir? I assume I want the four wheel disc master from the s-10?
     
  4. Tito

    Tito New Member

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    It's been a while since I messed with any of the "newer style" master cyls with the plastic reservoir, but I'm pretty sure they just CAREFULLY pull out and push back in. I seem to recall they have a rubber seal or O-ring or something? I know I did this on the Fiero (ha ha) waay back when, so it couldn't have been that hard.

    The S-10 is disc front/drum rear, but I don't think GM was using residual pressure valves in the rear drums anymore by then, so I don't think it would matter. Again -- I'm not 100% sure (I haven't tried this).

    That leaves you with the choice of a "power" or "manual" master cyl for an '88 S10 and I'd probably pick the power one...

    FWIW, here's NAPA's pic of the '81 Camaro master cyl (click to link):
    [​IMG]

    And the '88 S10 unit (click to link):
    [​IMG]
     
  5. hot72rod

    hot72rod Veteran Member Gold Member

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    You could get the Old's version of the blazer's master cyl., as they cam with disc/disc.
     
  6. Zedzag

    Zedzag Veteran Member

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    Great info Tito. Those tanks look like they'll swap no problem.

    What year was the Olds disc/disc master?
     
  7. Tito

    Tito New Member

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    Olds Bravada didn't launch until 1991 and didn't get rear discs until 1997 or so(?). Looks like the 97 setup uses a 1" bore master cyl though. and 1998+ moved the outlets to the opposite side of the master cylinder.

    You can just go poke around over at napaonline.com (no, I'm not associated with them, but they have a great website)
     

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