Chevrolet 70 1969 Series, Shop Manual

Page: 616 / 913

POWER BRAKE 5-7
6. Exam ine lever (body) for cracks or distortion. If lever
is dam aged in any way, a new body and bushing as­
sem bly m ust be used.
ASSEMBLY (Fig. 1)
1. Place w orm and gear assem bly in position in body.
2. Place lock sleeve over w orm shaft, with socket-like
end of sleeve at hex end of shaft. Place lock spring in
recess form ed by sleeve and shaft.
3. Enter sm all end of w orm shaft through hole aligned
with pin in body. Press shaft in until distance from
sm all end of shaft to edge of body is .625 inches (5/8
inches). Install new welch plug in w orm shaft bore.
4. Position cover plates on body and attach with new
rivets. Covers m ust be flat and in good contact with
body after riveting.
LUBRICATION
Slack adjusters are perm anently lubricated by the m a n ­
ufacturer and require no periodic lubrication. However, if
a slack adjuster has been dism antled and repaired in ac­
cordance with these procedures, it becomes necessary to
lubricate upon reassembly.
A fter assembly, remove the plug from either cover plate
and install in its place an A lem ite fitting num ber 1625 (or
equivalent) using A lem ite tool num ber 5254 (or equiv-
P U S H L O C K SLEEVE IN T O
D IS E N G A G E H E A D O F W O R M
S H A F T T O M A K E A D J U S T M E N T
L O C K SLEEVE M U S T C O M E O U T
A N D E N G A G E H E A D O F W O R M
S H A F T T O L O C K A D J U S T M E N T
Lock Sleeve
Spring
Dowel
Lever
Rubber Plug
6 W o rm
7 W o rm Shaft
8 Gear
9 Cover Plate
T-2325
alent). Before installing this fitting m ake certain that it is
positioned in such a m anner as to perm it easy access for
periodic lubrication (if desired) when slack adjuster is on
the vehicle.
Slack adjusters are to be lubricated with regular chassis
lubricant.
STANDARD BRAKE CH AM BERS
Standard brake cham bers used on vehicles covered by
this m anual are m ade by three different m anufacturers;
Bendix-W estinghouse, M idland-R oss and W agner Elec­
tric. Figure 2 is a cross section which is typical of all
three m akes of cham bers. For assem bly and disassembly
purposes all are identical except:
1. Bendix-W estinghouse cham bers have a one-piece
clam p ring while the others have a two-piece clam p
ring.
2. M idland-R oss cham bers have a spring retainer in­
stalled on the push rod next to the pressure plate
while the others do not.
The following procedures apply to all standard brake
cham bers:
DISASSEMBLY (Fig. 2)
1. Before disassembling brake cham ber, m a rk the pres­
sure plate and non-pressure plate with relation to the
clam p ring so the bolts of the clam p ring will be at
the sam e location when assembled. This will elim inate
the possibility of installation interference when brake
cham ber is installed, and will assure correct location
of side air inlet opening.
5 6
1 Air Inlet Port
2 Pressure Plate
3 Diaphragm
4 Clamping Ring
5 Drain Hole
6 Return Spring
7 Non-Pressure Plate
8 P u s h R o d TPM-4848
Figure 1— Slack Adjusters Figure 2 — S t a n d a r d Brake C h a m b e r (T ypical)
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHO P M A N U A L