II
I
~"",;;;,";;;.c'
ATMOSPHERE
~.Y
•
"
Fig. 3 - Fully Applied
!>
-
"3]'
-( rod
.pm'l
6 _
Vah
'(
rod
7 -
TriKK
cr
..
m
10 -
EI"n
K~led
,1
0'
ll_Campin
15
-
M"t"r
q
lindcr
pu
. h rod
16
- I'"
...
",
le,-e.
!9 -
I'o"'er
pi"on
20
- l
'Oppel
a~n,t
!'ly
around
pedal
pivot point
(12)
pres
sing
trigger
arm
(7)
against
valve
rod
(6),
R
efe
r
to
Figure
1.
The
rod moves to
the
l
eft,
compresses rod
spring
(5),
and
lifts
poppet
assembly
(20)
from
the
atmosphere
seat
on piston (19). Atmos-
phere
from
the
left
cylinder
cham
ber
enters
the
right
cylinder
chamber
balancing
the
piston
in
atmosph
ere.
Piston
return
spring
(18) r
e-
turns
the
piston to
the
left
in
vacuum cylind
er
(3).
The
for
ce
from
m
ast
er
cylinder
rod
(15),
together
with
pedal
return
s
pring
(17)
rO-
tat
es
brake
pedal (14)
and
power lev
er
(16)
counter-clockwise
to
the
ir
released positions.
In
the released position,
the
force of
return
spri
ng (17)
maintains
a
pressure
against
rod
(6)
thereby
in
suring
that
the
atmosphere
port
of
piston (19)
remain
s open.
Operation Durinq
No
Power Condition
Tn
case
of
a vacuum
failure
in
the system,
power
cylinder
piston (19) will be inactive
and
will
remain
in
its
released position, (See
Figure
1,
"Released
Position.")
In
this case
pin
(8) slides
freely
to
the
right
in
forked
clevis
slot
(9).
This
relieves the
bra
ke
pedal of
the
piston force,
therefore
dec
rea
sing
the
pedal
pressure
re-
Quired. Pedal l
ever
(14)
rotates
clockwise caus-
ing
pin (11) to move
to
the
right
side of slot
(10).
This
lo
cks power lever
(16)
to
the
brake
pedal.
Master
cylinder
rod
(15) is
then
forced
into
the
master
cy
linder
applying
the brakes.
The
foot
pressure
now
required
for
an
equiv-
alent
mast
er
cylinder
pressure
is g
reater
than
in
the
case when the power cy
linder
is
operat-
99
ing.
Under
the
no power condition,
the
pedal
ratio
is equal to
the
distance
from
pedal
pivot
(12)
to
the
pedal
pad
as
compared
to
the
dis-
tanc
e from
pivot
( 12) to
point
at
which
power
lever
(16)
is
attached
to
master
cylinder rod
(15).
DISASSEMBLY
AND
ASSEMBLY OF
POWER
UNIT
Disassembly
CAUTION:
Do
not
clamp yoke
in
vise during
any
opemtion.
Re
fer
to
Figure
4
and
proceed
as
follows:
Scribe
across
air
cleaner
cover,
vacuum
tube
and
plate,
and
cyli
nder
shell
as
a guide
to
cor-
rect
reassembly. Remove
three
air
cleaner
cover screws,
air
cleaner
cover,
and
hair.
Re-
move
the
four
remaining
tube
plate
screws;
sep-
arate
tube
and
plate,
and
gasket
from
vacuum
cylinder.
Slide
end
of
hose
from
vacuum
tube.
Scribe
acr
o
ss
flange
of
cylinder
and
end plate
as
a guide to
correct
reassembly. Remove
four
cylinder
bolts
and
nuts,
and
remove cy
li
nder
shell
and
rubber
ring
gas
ket.
Scribe across tube
plate
and
piston
plate
to
insure
correct
reassembly. Remove hose
from
vacuum plate
and
rubber
diaphragm
from
end
of
tube
fitting.
Using
thin
nose pliers, pull
out
diaphragm
balancing
pin. Remove
four
tube
and
plate
attaching
screws;
separate
tube
and
valve
poppet
parts
from
piston
plate;
separate
plate,
poppet
spr
in
g,
and
diaphragm
from
pop-
pet.
From
opposite end of assembly, remove valve
rod
rubber
seal. Use
Tru-Arc
snap
ring
pliers
an
d remove
snap
rin
g,
re
tainer
washer,
spring,
and
frict
ion collar. Remove valve
rod
from
pis-
ton rod.
NOTE:
D1-ive
out piston retaining pin I,·om pi8-
ton
(pa1·t
w a
y)
and note
il
piston is Iree on
piston
f'od.
If
piston is
/1'ee
on
1Jiston
rod, hold
spring comp1'essed while removing retaine-r
1)in
1,·0111. piston. II piston is tight on piston l'od
alte,' ,·elainer
pin has
be
en removed use a %
inch
dia'l1lele,'
"ouoo
b1·a·ss
"od
with
squared end
to
drive out piston rod
Ir01n
piston.
Separate
piston rod, end
plate
and
return
spring
from piston. Remove
rubber
stop
washer
from
piston rod.
Scribe across
mounting
ring
and
end
plate
to
insure
correct
rea
ssembly of
parts.
Remove
four
bolts
and
lockwashers
and
separate
mount-
To Next Page
Loading...
