Sunbeam ALPINE I SERIES: APLINE II SERIES, Workshop Manual

Page: 272 / 413

WSM.124
Section K (Brakes)
4th re-issue
Page 13
ALPINE
HANDBRAKE ANTI-RATTLE SPRINGS
The anti-rattle springs shown in Fig. 7A must be in
equal tension, otherwise binding may occur on one
side. An important factor controlling the tension
of the springs is the positioning of the brake rod
anti-rattle spring clips. On cars built after chassis
B9110954, the clips are positively located on the
adjustable side by a distance piece and are welded
onto the rod on the non-adjustable side. On cars
built prior to this chassis number, the dimensions
given in fig. 7A should be carefully checked in
cases of brake binding. Check also that t�e clips
are in correct alignment as shown In the end views.
HYDRAULIC SYSTEM
GENERAL
Great cleanliness is essential when dealing with any
part of the hydraulic system, and especially so
where the brake fluid is concerned. Dirty or aerated
fluid must never be added to the system.
Use only the specified type of brake fluid for
topping up the reservoir. (See Section P).
BLEEDING THE SYSTEM
"Bleeding" (expelling air) the hydraulic system is
not a routine maintenance operation and should
only be necessary when a portion of the hydraulic
system has been disconnE:cted or if the level of the
brake fluid in the reservoir has been allowed to fall
so low that air has entered the master cylinder.
Always keep a careful check on the fluid level in the
reservoir during bleeding. It Is most Important
that the master cylinder be kept at least half full
otherwise air may be drawn in necessitating a fresh
start.
Two people are required to carry out the operation.
Procedure
1. With all the hydraulic connections secure and
the reservoir topped up with fluid, remove the
rubber cap from the near-side rear wheel
cylinder bleed screw and fit the bleed tube,
Immersing the free end of the tube in a Jar
containing a little clean brake fluid.
2. Unscrew the bleed nipple three-quarters of a
turn, operate the brake with a fairly fast full
stroke, tightening the bleed screw at the end
of the stroke before allowing the pedal to fly
back unassisted. Any check to the return of
the pedal or master cylinder piston will
prevent effective bleeding. One or two faster
applications should now be made, tightening
the bleed screw at the end of each downward
stroke and opening again after the pedal has
fully returned. Repeat the applications until
the fluid entering the jar is completely free of
air bubbles, then tighten up the bleed screw.
Make sure that the bleed screw isfully tightened
before the pedal reaches the end of Its final
stroke.
3. Repeat the above operations for each of the
remaining three brakes, finishing at the wheel
nearest the master cylinder.
4.
Top up the reservoir to Its correct level oft·
(13mm) below the bottom ofthefiller cap orlfice.
Care should be taken
not to
over-tighten the bleed
screws since this may very
easily
result In stripped
threads. For the
correct
torque
figures
see
under
"Maintenance".
MASTER CYLINDER
Description (See Fig. 8)
The master cylinder is situated under the bonnet on
the bulkhead immediately in front of the brake
pedal. On right-hand drive cars the fluid reservoir
Is cast Integrally with the cylinder body, and Is con­
nected with it hydraulically by a drilling into the
centre of the end of the pressure cylinder. On left­
hand drive cars the fluid reservoir Is mounted separ­
ately on the wing valance and Is connected to the
end of the pressure cylinder by a metal pipe and
union nuts. (See Inset).
When pressure Is applied to the brake pedal, the
plunger (8) moves up the bore of the cylinder and
the valve seal (4) closes the port to the reservoir.
The seal is held Initially on its seat by spring washer