I lifted up on my brake pedal and the arm that pushes on the master cylinder fell out. What is missing that keeps this from happening? It looks like the previous owner had a piece of steel tie wire tied on to the arm of the brake pedal. I guess it broke. Glad I discovered this in the shop and not while I was cruising down the road.

 

I assume you have manual brakes. There is a retainer that holds the pushrod in the back of the M/C. Apparently whoever installed that M/C neglected to install that retainer. This is not safe to drive for the reason you've found.

 

Joe,
Does the retainer clip get installed where the rod from the pedal pushes on the plunger of the M/C?
Is this a part that is readily available?

 

Found these parts on Inlinetube. I ordered the complete kit. This should solve the problem of the push rod falling out.These parts are in the new products portion of the website

INL12439 1964-79 GM Master Cylinder Cup 1pc
INL12440 1964-74 Gm Master Cylinder Push Rod Manual Brakes 1PC
INL12441 1964-72 A-Body, 67-69 F-Body, 68-74 X-Body Manual Brakes Master Cylinder Push
Assembly Price
$16.75
$16.75
$51.50