Master cylinder question...may convert

I know that the rod as purchased was no where near as long as I needed. Once I added the extension it had all the pedal height adjustment and travel I needed.

For the light it doesn't take much to get it proper sized. Maybe .010 or so on the one I had. You will read where guys tried 3 or 4 switches until they found one that worked, thinking it was bad switches. Actually, all they finally found was a switch with more play in it that worked with the larger sized rod.

 

The way it works (at least as far as I know) is the pedal with the switch attached, moves slightly towards the firewall before the rod does - pushing the rod back against the switch. There has to be just a slight gap between the rod and the switch at rest to turn off the light.

 

Here is a pic of the Drake disc/disc in my '72. I made the lines myself so I don't remember which ones had a different flare nut size from stock. The distribution block is also a Drake product.
Hope the pic helps.

 

The one I bought was made for Fords, and yes, the rear reservoir is the front brake, front reservoir is rear brake.

Mine carried this part # C7ZZ-2140-4WDB

 

I didn't have any issues like that. I can take the switch, bushings, sleeve and rod - all off the pedal - once the special shaped clip is off.

Yes, getting old rod out of the old master is a hit and miss. Sometimes nothing will get them off and other times they do come out without damage.

 

Yes, Ford had many switches. My comment was in thinking about guys that keep taking a new Balkamp or Standard Products switch back to the parts store, claiming switch is defective. Until they get one that works. I have read several posts like that - about new parts store switches.

Here is a pic of a Maverick rod I pulled - and a pic of the Drake adjustable rod from the Internet (if someone has one, take a picture of the rod's switch contact and post it - mine is in the car already so I used the internet picture) - see how the new Drake rod is thicker at the switch contact? That is what I was talking about shaving down to prevent the switch from staying on and keeping the brake lights on all the time.

 

Found this great, simple diagram on how these Ford switches work. Might clear up some misunderstanding of how and what activates the brake light. Note the red line shows the air gap between the rod and the switch when the pedal is at rest.