Bentley R Type - Page 50

46
TnB
'R'
TypB
BBwrrBv.
Fuel Pumps.
The Juel pumps
(1
and
2,
Fig. 11)
are
of
the
electric,
solenoid-
operated,
djlph_1agT
type,
ald
comprise
two
independent
pumps
complete
ryith
diaphragms,
solenoids,
contact
trip
mtchanism!,
and
suction and
delivery
valves.
Fot\
pumps
deliver into
a common
chamber
and
are
simultaneously
rendered
operative
when
the
ignition
and
master switches
are
tronri.
Duplicate
puqps
?re
provided
primarily
to
ensure reliability.
They
also
ensure
that
there
shall
be no
starvation
of fuel
at
maximum
engine
demands.
If
it
should
ever
be necessary
to
disconnect
the
fuel pipes
at
the
pumps,
it
is important
first
to release
the cover
of
the iear
filter.
(See page
47.)
This
will
prevent
loss
of fuel
by
syphoning,
due to
the
location
of
the
pumps
below
the level
of
the inairi
tank.-
The current
supply
for
the pumps
is
taken
through
the ignition
fuse.
Faulty Opcration
of Pumps.
This would
_
cause-
failure,
or
shortage,
of
fuel
supply
to
the
carburetter,
and
may
be
due to
one
or
moie
of the
folowing"c"oter:-
r. Shortage
of
fwel
in-.the
tank.-This
should
have
caused
the
green
warning
lamp
to light,
but
if
the tank
has
been
allowed
to run
dry,-.the pumps
will
tick
continuously
and noisily.
On severe
gradients.
and
side
slopes,
these
symptoms
may
occur
before
the tank is
completely
empty,
due to
surging
of
firel in
the tank,
which
may
uncover
the
suction
pipe.
z.
Air
leak
on
the
suction
side.-Either
at
the
filter
or
on
the
pipe
lin_e.
A
slight air
leak
will
cause
the
pumps
to
work
rather.
faster
than
normal,
but
if _sufficiently
bad
to
tause
a
complete
air
lock,
the pumps
will
tick
continuously
and
noisily
as if
short
of
petrol.
t.
ruy-tf
aal,aes
not se.ating.-
Thg
delivery
valves
do
not give
any
easily
detectabl_e
signs
of
their
functioning.
If a
sucti5n
valvt
is
not
seating,
the pump
will
tick continuo-usly
when
the engine
is
switched
on
but
not
running.
I!
is pro6able
that
forEign
matter
is
lodged
under
one
of
tlie valves.
If the above
is
suspected,
remove
the
caps
,(3,
Fig.
11
),
the
valves
and
valve
cap assemblies
may
their
ni: titte?
oui
and
clgned.
4.
sl,uggish
operation
of
the
pumps,-check
that
the
electrical
connection
and
cont-act
-points
-are
clean
and in proper
order.
Jerify,.by-
alternately
disconnecting
the
pipes
"t
th"
unions,
that
it is the pump,
and
not
due
to a utoct<aee
in
the
pipe
line.
If with the pipes-disconnected
the
pumps
stfu
work
slufgishly,
the unit
should
be
removed
and
returned
to
Messrs.
E"entltiy
Motors
-(rggt)
Ltd.,
or
one
of their
"special
Retailers"
for
overhaul.