Manual Brake Input Rod Differences
by George Nenadovich
Here are two manual brake input rods for GM cars. The top
manual brake input rod is for 70 and earlier models that have the master
cylinder with a deep counter bore. The lower rod is for 71-2 models that
use the master cylinder with the shallow depression/countersink. The upper
rod overall length is 6 inches while the lower rod is 4 inches....this does
not include the "fork"
Here is a close up of the lower manual brake rod...notice
there is a metal cup and the rod end is flared. The metal cup maintains
the rod in the firewall opening.....keeps it centered and it can not fall
out. The top rod does not have this feature because the deep counterbore
in the master cylinder keeps the rod in position. You can not interchange
the two rods.
Here is a new master cylinder (rectangular style...not the
"bath tub" style) Notice the countersink is very shallow.....the
shorter manual brake rod goes with this master cylinder.