Sunbeam ALPINE I SERIES: APLINE II SERIES, Workshop Manual, Page: 292 / 413

WSM. 124
Section K (Brakes)
(25) allowing a flow of hydraulic fluid between the
brake assemblies and the fluid reservoir of the
master cylinder.
If the brake pedal pressure was increased instead
of being decreased ·the control valve operates to
give additional assistance until the thrust on each
end of the valve control piston is balanced or until
the limit of available vacuum is reached. Con­
versely, if the pedal pressure is only reduced, the
control' valve operates to reduce the hydraulic
pressure in the brake assemblies until, again, a
state of balance of the valve control piston is
reached.
SERVICING
Whenever possible the Girling Vacuum Servo Unit
should be returned to the manufacturers for re­
placement but if this Is not possible the renewing
of all seals as contained in the Service Kit should
provide a satisfactory unit providing the internal
working surfaces are in good condition.
There should be no sign of corrosion, pitting,
scoring or steps on the piston rod, pistons or
bores and the surfaces should be smooth to
the touch.
When dismantling, absolute cleanliness Is essential.
Wash the hands and lay out a clean sheet of paper
on which to work and place the parts. Take care
of all highly finished working surfaces on pistons,
rods and bores. Clean hydraulic parts with Girl­
ing Cleaning Fluid, Alcohol or Girling Brake and
Clutch Fluid (Crimson) and do not allow any other
fluid, oil or grease to touch them. Special care
should be exercised when removing or refitting
the circlip in the hydraulic output cylinder and
when re-assembling the vacuum cylinder to the
body. On some servo units a screw and locknut Is
fitted to the end cover, IN NO CIRCUMSTANCES
MUST THE SCREW BE DISTURBED.
AIR FILTER
The air filter element Is of a moulded cellular
construction and sho'uld be renewed in accord­
ance with the Instructions given In the Owners
Instruction Book.
To renew
2nd
re-issue
Page 33
Remove the cover from the top of the servo unit
by moving aside the spring clip and discard the
soiled filter beneath. Clean the base plate and
cover, position the clean filter on the base plate
followed by the cover and secure the cover with
the dip.
Alternately, remove the cover by withdrawing the
centre screw, discard the soiled filter beneath but
salvage the rubber washer. Clean the rubber
washer and cover, position the rubber washer on
the servo unit followed by the clean filter and
cover; secure the cover with the centre screw.
SERVO UNIT
To remove and refit
I. Detach the vacuum pipe from the cast body
of the servo unit by releasing the union nut.
2. Detach the hydraulic Inlet and outlet pipes
from the cast body by releasing the union
nuts, tra'pplng any escaping hydraulic fluid
in a drip tray.
3. Remove the servo unit from the bracket in
the engine compartment by withdrawing
three bolts and washers; one nut, bolt and
washer.
4. Refitting Is the reverse of the removal
sequence but the hydraulic system must be
bled of air as previously described.
To dismantle and re-assemble (Fig. 20)
I. Grip the servo unit in a vice by the two
lower lugs on the cast body.
2. Remove the piston assembly (5) spring (6)
gasket (I) and end cov.er ( 15) from the
vacuum cylinder (19) by removing the trans­
fer pipe retaining plate and seven nuts and
bolts while controlling the pressure of the
spring (6). When fitted DO NOT DISTURB
THE SCREW AND LOCKNUT IN THE
END COVER (15).
3. Remove the vacuum cylinder ( 19) and gasket
from the cast body (29) by withdrawing three
bolts, washers and a clamping plate and
easing the grommet in the flange of the
cylinder from the transfer pipe (17).