Hudson 1955 Rambler, Technical & Service Manual

Page: 188 / 292

Residual Check Valve
During application, the fluid passing
throaugh the master cylinder outlet causes
the rubber lip of the residual check valve
to expand allowing the fluid to pass to the
lines and wheel cylinders. Upon release, the
hydraulic pressure existing in the lines
forces the residual check valve spring to
compress moving the check valve slightly off
its seat. As the pressure decreases, the
residual check valve again seats holding a
slight pressure in the lines and wheel
cylinders preventing air from entering the
system (Fig. 13).
POWER BRAKE UNIT DISASSEMBLY
Power Cylinder
NOTE: Always use extreme care in
handling hydraulic system parts to
prevent their coming in contact with
mineral oil, gasoline, or kerosene.
When overhauling the unit, always
use repair kits.
Place the unit in a vise and remove the
rubber dust guard retaining spring, dust
guard, and felt washer from the end plate and
plunger push rod.
Bend up two tabs on the end plate and
remove the plate and gasket. Remove the
vacuum hose from the tube attached to the
vacuum cylinder. Remove the vacuum and
atmospheric pressure tube assembly attaching
screw and remove the assembly from the vacuum
cylinder shell.
Remove power piston assembly from the
vacuum cylinder shell.
Compress the vacuum piston return spring
far enough so that the "C" washer can be
removed from the groove in the master
cylinder piston rod. The retaining plate and
vacuum piston return spring can now be
removed from the vacuum cylinder shell.
To insure proper reassembly, scribe a line
across the ouside of the vacuum cylinder
shell and master cylinder housing. Remove the
three screws attaching the vacuum cylinder
shell to the master cylinder.
Lift off the vacuum cylinder shell and
remove gasket and rubber ring. Push master
cylinder piston rod into master cylinder and
remove the leather seal from the master
cylinder (Fig. 16).
Master Cylinder
Remove cover and gasket and drain fluid.
Place the master cylinder in a vise. Use a
1-1/8" socket and remove the compensating
valve from the master cylinder.
Loosen the outlet and residual valve fittings
but do not remove them (Fig. 12).
Remove stop washer retaining ring with Tool
J-4245 "Truarc" Pliers.
NOTE: If ring is of Spirolox type,
use a sharp pointed tool to pry end
of ring out of groove.
1.Vacuum Cylinder
2. Gasket
3. Rubber Ring
4. Leather Seal
5. Piston Rod
6. Master Cylinder Housing
FIGURE 16— Removal of Vacuum Cylinder
from Master Cylinder Housing
Pull master cylinder piston rod out of
master cylinder.
Remove stop washer, piston rod washer, cup
and cup retainer ( Fig. 17).
1. Retaining Ring
2. Stop Washer
3. Piston Rod Washer
4. Cup
5. Cup Retainer
6. Piston Rod
7. Master Cylinder Housing
FIGURE 17— Master Cylinder Piston Rod and
Operating Parts
Remove master cylinder from vise; hold it
upside down and remove the outlet fitting and
residual check valve assembly (Fig. 18).
Clamp compensating valve in vise and remove
spring retainer, spring valve, and rubber seal
(Fig. 19).
Vacuum Piston and Valve Assembly
Remove vacuum hose, tube, and tube seal from
piston assembly.
10 TECHNICAL SERVICE MANUAL