MG MGB User Manual

D
THE
FUEL SYSTEM
Fig. D.l
Fitting the rocker
assembly
to
the pedestal.
(Inset) the
correct
position of the
centre
toggle
spring
7. Push
out
the hardened
steel
pin
which holds
the
rocker mechanism
to
the
pedestal.
BODY
AND VALVES
(type
AUF
300)
8.
Unscrew the
two
Phillips
screws
securing
the valve
clamp plate,
remove
the
valve
covers,
valves, sealing
washers.
and
■lter.
NOTE.~Dismantling
of the delivery
flow
smoothing
device
should
only be undertaken
if
the
operation of
it
is faulty,
and if the
necessary
equipment for
pressure-testing
after
assembly
is available.
On
this
understanding
proceed
as
follows:
9.
Remove the four
4 BA.
screws
securing
the
delivery
■ow
smoothing
device
vent
cover,
remove
the
cover,
the
diaphragm
spring,
rubber
‘0’
rings,
spring
cap,
diaphragm,
barrier,
diaphragm
‘plate,
and
sealing
washer.
10. Remove
the single
2 BA.
screw
securing
the inlet
air
bottle
cover, remove
the
cover
and
gasket.
11. Unscrew the inlet
and
outlet
connections.
BODY
AND VALVES (type
HP)
12. Remove the
inlet
union,
the
outlet
union,
the outlet
valve
cage,
and
the
inlet
valve
disc.
Remove
the base
plug and filter.
Inspecting
GENERAL
If
gum
formation
has
occurred
in
the fuel
used
in the
pump,
the
parts
in
contact
with
the fuel
will
have
become
coated with
a
substance
similar
to
varnish. This
has
a
strong,
stale smell and
will
attack
the
neoprene
diaphragm.
Brass
and steel
parts
so
affected
can
be cleaned
by
being
boiled
in
a
20
per
cent.
solution of
caustic
soda,
dipped
in
a
strong
nitric
acid
solution,
and
■nally
washed
in
boiling
water.
Light
alloy
parts must
be well
soaked
in
methylated
spirits
and then
cleaned.
1.
Clean
the
pump
and
inspect
for
cracks, damaged
joint
faces,
and threads.
2.
Clean
the ■lter
with
a
brush
and
examine
for
fractures.
Renew if
necessary.
3.
Examine the
coil lead
tags
for
security
and the lead
insulation for
damage.
4.
Examine the
contact
breaker
points
for
signs
of
burning
and
pitting.
If
this
is
evident the rockers and
spring
blade
must
be
renewed.
5.
Examine the pedestal
for
cracks
or
other damage
particularly
to
the
narrow
ridge
on
the
edge
of
the
rectangular hole
on
which the
contact
blade
rests.
6. Examine the diaphragm for
signs
of
deterioration.
7. Examine the
non-return vent
valve
in
the
end
cover
for
damage, and
ensure
that the small
ball valve
is
free
to
move.
TYPE
AUF
300
8.
Examine
the plastic valve assemblies for kinks
or
damage
to
the
valve plates. They
can
best be checked
by
blowing
or
sucking with the
mouth.
9.
Check that
the
narrow
tongue
on
the
valve
cage
which
prevents
the
valve being forced
out
of
position,
has
not
been distorted
but allows
a
valve lift of
approximately
T16
in.
(1.6 mm.).
10. EARLY PUMPS:
Examine the
delivery ■ow
smoothing
device diaphragm,
barrier, plate,
spring,
and
spring
cap
for
damage. if
in
doubt,
renew
the
diaphragm.
LATER PUMPS:
Examine
the delivery
air
bottle
diaphragm.
1].
Examine
the inlet
air
bottle
cover
and gasket
for
damage.
12. Examine the
valve
recesses
in
the
body for
damage
and
corrosion.
Ifit
is
impossible
to
remove
the
corrosion
or
if the
recesses
are
badly
pitted the
body
must
be
discarded.
TYPE
HP
13. Remove the
circlip
in
the
outlet
valve
cage
and
examine
the
inlet
and
outlet
valve
discs for
signs
of
wear.
Scrap,
if
worn.
l4. Examine the
valve
seat
in
the
body
and outlet
valve
cage
for
damage
and
corrosion.
If
it is
impossible
to
remove
the
corrosion
or
if the
seat
is
pitted the body
or
cage
must
be discarded.
AVJIOC.
Fig.
D.2
Setting the diaphragm.
Unscrew
until
the
rocker just ‘throws
over’
MGB.
Issue6.
69615

MG MGB Specifications

General

Brand	MG
Model	MGB
Category	Automobile
Language	English