85 GMC jimmy master cylinder, fitting sizes?

[cybrfire]

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?

 

[mikey_d05]

Uh Oh! Problems?

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

 

[cybrfire]

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".

 

[mikey_d05]

Not possible that it's 11/32"?

 

[diesel4me]

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..