GMC 1976 ZEO 6083 Maintenance Manual page 572

9- 4 0 STEERING
Figure 66-Torque Wrench Reading
3 . Rotate the torque wrench approximately 45
degrees each side of center and "read" near or on
center (highest reading) (figure 66). Loosen the lock
nut and turn the preload adjusting screw CW until
the correct "O" center torque, in excess of the read-
ing just taken, is obtained (figure 66).
4. Limits for "new" and "used" gears are differ-
ent, as follows:
a. "New" gear over-center torque to be 4-8 in .
lbs. additional torque .
b. "Used" gear (400 or more miles) . Over-
center torque to be 4 to 5 in . lbs. additional torque .
Tighten the locknut to 35 ft. lbs. while holding
the preload adjuster screw. Recheck the "O" center
adjustment .
BLEEDING POWER STEERING
SYSTEMS
When a power steering pump or gear has been
installed, the air that has entered the system must be
bled out before the vehicle is again operated . If air is
allowed to remain in the power steering fluid system,
noisy and unsatisfactory operation of the system will
result . Bleed air from the hydraulic system as fol-
lows :
NOTE :
Add only new power steering fluid (GM
1050017 or equivalent) to power steering sys-
tem .
1 . Fill oil reservoir to proper level and let oil
remain undisturbed for at least two minutes.
2 . Start engine and run momentarily.
3 . Add oil if necessary .
4. Repeat above procedure until oil level remains
constant after running engine .
5. Raise front end of vehicle so that wheels are off
the ground .
6. Turn the wheels (off ground) right and left,
lightly contacting the wheel stops.
7. Add oil if necessary.
8. Lower the vehicle and turn wheels right and
left on the ground .
9 . Check oil level and refill as required .
10 . If oil is extremely foamy, allow vehicle to
stand a few minutes with engine off and repeat above
procedure.
11 . The presence of trapped air in the system will
cause the fluid level in the pump to rise when the
engine is turned off. Continue to bleed system until
this condition no longer occurs .