[DeTomaso] rebuild kit for mystery master cylinder?

[JDeRyke at aol.com]

In a message dated 3/25/10 10:08:55 AM, pantdino at aol.com writes:

> The reservoir for the front brakes is like 5X larger (longer) than the 
> one for the rear brakes. 
> The top is moulded, raised, sheet metal that is held in place by a spring 
> steel bar that slides over it.
> I need to find a rebuild kit for it.  Does it sound like a GM Corvette 
> cylinder?
> 
> 
GM, at least; some Chevelles, Z-28s etc also used such. I'd take the thing 
off and take it to a good auto parts store such as a big NAPA for a match 
up.
Two thoughts: most older masters were for drum brakes on at least one end, 
and GM always incorporates a residual pressure valve in the outlet line(s), 
behind the flair fitting. Note the rear brake system is usually the end of 
the master cylinder furthest from the firewall and brake pedal. To check for 
a residual pressure valve, run a sheet metal screw into the brass ferrule 
that forms the flair-fitting socket, and pull the press-fit brass part out 
with Vise-grips. If there's a strange rubber thingy inside, thats the valve. 
Valves for discs and drums look identical which is why I use NONE. Disc brake 
valves are 2 psi while drum brakes use up to 10 psi. Use a drum-brake master 
on discs and the system will perpetually drag its pads. Good luck- J DeRyke