Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

85 GMC jimmy master cylinder, fitting sizes?

Discussion in 'The Garage' started by cybrfire, Sep 27, 2006.

  1. cybrfire

    cybrfire 1 ton status Vendor GMOTM Winner

    Joined:
    Dec 15, 2002
    Posts:
    15,140
    Likes Received:
    565
    Location:
    Iowa
    Anybody know the fitting sizes? I believe the rear line is 5/16". The front is larger but not quite 3/8". could it possibly be metric?
     
  2. mikey_d05

    mikey_d05 1 ton status GMOTM Winner

    Joined:
    Nov 23, 2004
    Posts:
    10,453
    Likes Received:
    0
    Location:
    Minnesota
    Uh Oh! Problems? :o

    My line was a different size as well, ended up reusing the old fitting.
     
  3. cybrfire

    cybrfire 1 ton status Vendor GMOTM Winner

    Joined:
    Dec 15, 2002
    Posts:
    15,140
    Likes Received:
    565
    Location:
    Iowa
    Yep! Can't quite seem to figure out the line size. I think its metric. Rear line, 5/16" threads right in but the front line, is larger but not quite 3/8".
     
  4. mikey_d05

    mikey_d05 1 ton status GMOTM Winner

    Joined:
    Nov 23, 2004
    Posts:
    10,453
    Likes Received:
    0
    Location:
    Minnesota
    Not possible that it's 11/32"?
     
  5. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,553
    Likes Received:
    939
    Location:
    Massachussetts
    adapters..

    Many master cylinders have different "ports" than the original,and need an adapter to make the stock lines fit..I ran into this daily when I worked the parts counters..some masters have a 9/16-18 machine thread,with a flare seat,and the 1/4 line GM used factory had a fitting with larger threads than a "normal" 1/4" line has...these fittings are a pain to find ,especially on sunday..:crazy:
     

Share This Page