1954/1955 brakes?

[Caddy Wizard]

Cadillac "Serviceman" information says that the 55 brakes were somehow improved over the 54 brakes by moving a "check valve" (or "residual check valve") from the master cylinder to the HydroVac power booster.  But aren't the 54 and 55 master cylinders identical?  Anyone have the straight skinny on this?

[P W Allen CLC# 20193]

Art,

The Master Parts Book does list two different master cylinders for the 55's. One without power brakes (545 4401) and one with power brakes (545 4540). This is confusing to me because I was under the impression that after 1953, power brakes were standard. But maybe not.

[Caddy Wizard]

I don't know if you could special order a car without power brakes.  But the interesting thing about the parts listing is that the 54 part number for a master cylinder with power brakes does appear to be a different number than for a 55 with power brakes.  So maybe they did change the master in 55.


But I wonder if you buy a new master from one of the vendors today for a 54 vs a 55, will you get the right one for your year?  (with or without the residual check valve)...