Chevrolet 70 1969 Series, Shop Manual

Page: 618 / 913

POWER BRAKE 5-9
1. Install boot, rod, guide and diaphragm in n on­
pressure housing.
2. Position pressure housing on non-pressure housing so
that scribe m arks m ade at disassem bly are aligned.
3. Install clam ping ring on assem bly and secure with
bolt and nut.
DD3 BRAKE ACTUATOR (CHAMBER)
(Refer to Figures 4 and 5)
DISASSEMBLY
1. Clean brake actuator exterior of all road grime.
M ark it in such a way that it can be reassembled co r­
rectly.
2. Rem ove yoke and yoke lock nuts.
3. Rem ove boot, splash guard, retaining spring and felt
breather.
ASSEM BLY (Fig. 3)
4. Rem ove auxiliary and service clam ping ring nuts and
bolts. Spread clam ping rings slightly, just enough to
slip them off plates. It m ay be necessary to use a soft
m allet driver to break the clam ping rings loose. If
rings are being reused, caution should be taken
against bending them out of shape.
5. A fter clam ping rings are removed, auxiliary pressure
plate, parking diaphragm , service pressure plate and
service diaphragm are rem oved in that order.
6. Place the rem ains of actuator on a sm ooth surface
with the push plate down. C onnect an air supply
(shop air) line to the locking port. By hand press
down on the actuator non-pressure plate and at the
sam e tim e apply air to the locking port. As the shaft
is unlocked, ease the non-pressure plate back and re­
move push plate and shaft assem bly with push rod
and return spring.
7. Hold lock cap dow n against roller spring tension and
com pletely remove all four (4) cap screws before re­
leasing and removing cap.
8. Remove roller spring and spring seat washer.
9. R em ove all eight (8) rollers.
10 11 12 13 14
25 24
1 Auxiliary P r e s s u r e Plate 11
2 Auxiliary D i a p h r a g m 12
3 Auxiliary C la m p Ring 13
4 Service P r e s s u re Plate 14
5 Service D ia p h r a g m 15
6 S ervice C la m p Ring 16
7 N o n- Pressu re Plate 17
8 Return Spring 18
9 Piston G r o m m e t 19
10 Piston 20
Collar
Retaining Spring
Splash G u a r d
M ounting Bolt
Roller
Spring Seat W a s h e r
Roller Spring
L o c k C a p
Boot
Push R o d
21
22
23
24
25
26
27
28
29
L o c k Nut
Adjusting Nut
Clevis
Clevis Pin
Cotter Pin
Retainer Ring
L o c k Port
Service Port
Parking and E m e r g e n c y Port
Figure 4 — DD3 Brake Actuator (Cham ber) Assem bly
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHO P M A N U A L