Topic: 1965 Mustang GT Leaking Cap on Master Cylinder

[rocket289k]

Hi Guys,

The cap on my new master cylinder is leaking.  The master cylinder, the cap and the gasket are brand new.  It's causing quite a mess not to mention messing up the paint in my engine compartment.  Has anyone else run into the issue? 

I checked to see if the gasket is installed correctly (as I've seen some gaskets installed upside down with the "plunger" part of the rubber gasket pointing upwards to fit the contour of the cap as opposed to the plunger of the rubber gasket pointing down so it would sag against the brake fluid and eliminate the pocket of air).

Thoughts?

Ron

[Jays66gt]

Is it a new power set up or an original set up?  I would try tweaking the clamps and see what happens.

[J_Speegle]

Not that it will help in this situation but there was a revised master cylinder cap gasket released in the spring of 66 for disc barkes. Design difference a set of ribs on the matting surface with the base.

[rocket289k]

Hi Guys,

It is the original style 65 setup (new master cylinder and cap) - didn't rebuild the old unit.  I'm going to try a new cap (the prior one I bought looks slightly bent to my eye).

Ron

[rocket289k]

Not that it will help in this situation but there was a revised master cylinder cap gasket released in the spring of 66 for disc barkes. Design difference a set of ribs on the matting surface with the base.

Hi Jeff - I presume the ribs make contact with the master cylinder itself (not the cap lid).


Regards,

Ron

[J_Speegle]

Hi Jeff - I presume the ribs make contact with the master cylinder itself (not the cap lid).

Beleive so since that is the side with the liquid

[rocket289k]

Ha! - well played    The reason I asked it that I've seen some reproduction lids with that gasket installed completely backwards.