Chevrolet 30 Series 1967 Service Manual page 467

General D e s c r ip tio n ......................................................... 9-13
Maintenance and A djustm en ts.......................................... 9-13
Power Steering Gear A djustm en t................................. 9-13
Bleeding Hydraulic S y s t e m .......................................... 9-13
Fluid L e v e l .....................................................................
Pump Belt Tension.........................................................
Hydraulic System C h e c k s ............................................. 9-14
All truck power steering installations consist of three
basic components, pump, control valve and power cyl­
inder, connected by hydraulic lines. The pump is a vane
type with the mounting to the engine peculiar to the par­
ticular model and engine application involved.
Two types of control valves are used, light-duty models
use the linkage type mounted between the pitman arm and
relay rod or steering connecting rod. Medium and heavy-
duty models use a rotary valve type, mounted on the
steering gear box between the steering shaft and worm
shaft.
POWER STEERING GEAR ADJUSTMENT
C-K10, 20 and C30 Series
The steering gear used with power steering is adjusted
in the same manner as the manual steering gear.
40, 50 and 60 Series (Fig. 24)
Sector lash adjustment is the only power steering gear
adjustment that can be made on the vehicle. However, in
order to make this adjustment, it is also necessary to
check the combined valve drag and worm bearing preload.
1. Remove steering connecting rod from pitman arm.
2. Loosen sector lash adjusting screw lock nut and back
off adjusting screw to the limit of its travel.
3. Disconnect horn wire and remove horn button cap.
4. Turn the steering wheel through its full travel, then
locate wheel at center of its travel.
5. Check combined valve drag and worm bearing pre­
load, with an inch-pound torque wrench on the steer­
ing shaft nut, by rotating through the center of travel
(approximately 10° in each direction).
highest reading.
. Tighten the sector lash adjusting screw until torque
6
at steering wheel nut falls within specifications.
NOTE:
If maximum specification is exceeded,
turn lash adjuster screw counterclockwise, then
come up on adjustment by turning adjuster in a
clockwise direction.
7. Tighten locknut and recheck pull as it must lie within
specifications.
. Reassemble steering connecting rod to pitman arm.
8
POWER STEERING
Page
9-14
9-14
GENERAL DESCRIPTION
MAINTENANCE AND ADJUSTMENTS
Note the
INDEX
Component Replacement and R e p a i r s .............................. ...
Power Steering P u m p ................................................... ... 9-15
Control Valve - C -K 1 0 -2 0 -C 3 0 .................................... ... 9-15
Power Steering Gear and Control Valve -
40-50-60 s e rie s ............................................................ ...9-16
Power C ylin der............................................................... ... 9-16
Power Steering H o s e s ................................................... ... 9-17
The power cylinders used differ in capacity and mount­
ing. C10-20-30 series have the cylinder mounted between
the frame and relay rod. The mounting for units equipped
with 9000 lb. front axle is between the frame and pitman
arm. Axle-to-tie rod mounting is used on all other
models.
Some medium and heavy-duty models use a power
steering oil cooler mounted at the front of the vehicle.
BLEEDING HYDRAULIC SYSTEM
1. Fill oil reservoir to proper level and let oil remain
undisturbed for at least two minutes.
2. Start engine and run only for about two seconds.
3. Add oil if necessary.
4. Repeat above procedure until oil level remains con­
stant after running engine.
5. Raise front end of vehicle so that wheels are off the
ground.
. Increase engine speed to approximately 1500 rpm.
6
7. Turn the wheels (off ground) right and left, lightly
contacting the wheel stops.
Fig. 24-40-50-60 Series Power Steering G e a r and
Control V a lv e (T y p ica l)
STEERING 9-13
Page
9 - 1 5
CHEVROLET TRUCK SERVICE M ANUAL