MG MGB User Manual

M
'
THE
BRAKING
SYSTEM
which
is
filled
with ■uid from the
supply
tank. 011 releasing
the brake
pedal
after
application
the
piston
is
returned
quickly
to
its
stop
by
the
return
spring. A
small bleed
hole
is
drilled
in
the side of the check
valve body
to prevent
any
■uid
pressure
being retained
in
the
system.
Removing
Remove the
screws
securing
the
brake and clutch
master
cylinder
cover
and take off the
cover.
Drain the ■uid from
the supply
tank
reservoir
by
attaching
a
rubber
tube
to
a
brake
calliper bleed
screw, open
the
screw one
full
turn,
and then depress the brake
pedal.
Hold
the pedal
down, tighten the bleed
screw,
and then let the
pedal
return
unassisted.
Repeat this
operation
until the
tank
is
empty.
Remove the
split
pin,
washer, and
clevis
pin
from the
push-rod and
disengage the brake pedal
lever.
Clean the
pipe connection,
disconnect the
pipe
line, and ■t
a
plug
to
the
end
of the
cylinder
to
prevent
the
entry
of
dirt.
Unscrew the fixing bolts
and detach the
master
cylinder
from the box
assembly.
Dismantling
Detach the rubber dust
cover
from
the
cylinder barrel
and
move
it
along the push-rod.
Depress the
push-rod
to
relieve the load
on
the circlip,
then
remove
the
circlip and the
push-rod
assembly.
Withdraw
the
piston,
piston washer,
main
cup,
spring
retainer,
and
valve
assembly.
Remove
the
secondary
cup
by
carefully
stretching
it
over
the
end of the
piston.
Assembling
Clean all
parts
thoroughly,
using
brake ■uid
or
methylated
spirit.
If
spirit is
used the rubber
should
not
be
allowed
to
soak
but should
be dried
and dipped
in
clean brake ■uid.
The
main casing,
if cleaned
with
spirit,
must
be dried
out
before
assembly.
Ensure that
the
compensating
port
in
the
cylinder barrel
is
clear by
probing with
a
piece
of ■ne
wire.
Examine
all the
rubber
parts
for
damage
or
distortion.
It
is
usually advisable
to
renew
the rubbers
when
rebuilding
the
cylinder.
Dip all the
internal
parts
in
brake
■uid
and
assemble when
wet.
Stretch
the
secondary
cup over
the
piston
with the
lip of
the
cup
facing
the
head of
the
piston.
When the
cup
is in
its
groove
work
it
round
gently with
the ■ngers
to
ensure
that
it
is
correctly
seated.
-
Fit the
check
valve
assembly
onto
the large
end
and the
spring
retainer
onto
the
small
end of the
return
spring
and
insert
the
spring,
check
valve ■rst,
into
the
cylinder.
Insert the
main
cup,
lip ■rst,
and
press
it
down
onto
the
spring
retainer, taking
care
not to
damage
or
turn
back the
lip.
Fig. M3
The brake
master
cylinder
1. Cylinder and supply tank
8. Washer—piston.
15-
Screw-Cylinder and
assembly.
9.
Piston.
stiffener
to
box.
2. Cap—filler.
10.
Cup
—secondary_
16. Washer—spring—screw.
3.
Seal—cap.
11.
Rod
-push.
17- Nut
—SCIeW-
4.
Valve assembly.
12.
Circlip.
18.
Banjo—mastercylinder.
5. Spring—piston
return. 13.
Boot. 19. Bolt—banjo.
6.
Retainer—returnspring.
14.
Screw—cylinder
to
box.
20. Gasket—banjo
connection.
7. Cup—main.
21. Gasket—banjo
connection.
M-4
MGB.
Issue
4.
69615

MG MGB Specifications

General

Brand	MG
Model	MGB
Category	Automobile
Language	English