Buick LeSabre 1965 Service Manual page 482

8 - 1 8 POWER STEERING STEERING GEAR, STEERING COLUMNS AND LINKAGE
conditions. Full hydraulic assist driver must apply to the steering the hydraulic oil pressure in the
is obtained with approximately wheel to turn the car. This pro- turn chambers should not exceed
3-1/4 pounds of effort at steering portional effort gives the driver 125 psi. Pressure for cornering
wheel rim. The more the turning the "feel of the road" at all should not exceed 400 psi and
resistance, the greater the pres- times. parking pressure may range up
sure in the right or left turn to 1100-1200 psi depending upon
chamber and the more effort the During normal driving conditions, the road surface.
8 - 1 1 TROUBLE DIAGNOSIS—POWER STEERING GEAR AND PUMP
NOTE: This paragraph covers only those causes of trouble which may be due to the hydraulic power
mechanism. Causes which are due to the steering linkage and front suspension are the same as de-
scribed for standard steering gear in paragraph 8-3.
a.
1.
2.
3.
4.
b.
1.
2.
4.
5.
c.
COMPLAINT AND CAUSE
HARD STEERING WHILE DRIVING
Lower coupling flange rubbing against ad-
juster plug.
Steering adjustment tight.
Insufficient pressure build-up in gear power
cylinder due to leak or faulty valve.
Incorrect installation or operation of the
gear check valve poppet.
1.
2.
3.
4.
POOR RETURN OF STEERING GEAR TO CENTER
Lower coupling flange rubbing against ad-
juster plug.
Tighten pitman sector to rack-piston nut
adjustment.
Rack-piston nut to worm preload too tight.
Thrust bearing adjustment incorrect.
Sticky valve spool.
PUMP INOPERATIVE OR POOR OR NO ASSIST
NOTE: Refer to subparagraph i, Step 4, to determine
1.
2.
4.
5.
7.
Loose drive belt.
Low oil level.
Air in the oil.
Defective hoses.
Flow control valve stuck open.
Loose screw in end of flow control valve.
Pressure plate not flat against ring.
1.
4.
5.
CORRECTION
Loosen pinch bolt and assemble properly.
There should be 1/16" clearance between
plug and flange.
Check adjustment by disconnecting pitman
arm from gear.
Replace defective parts.
Check operation of valve, paragraph 8-16,
subparagraph C, Step 6.
Loosen pinch bolt and assembly properly.
Adjust in car to specification.
Remove gear and replace balls as required.
Adjust to specification.
Remove and clean valve. Replace rotary
valve assembly if necessary.
if pump is at fault.
1.
3.
4.
5.
7.
Tighten belt.
Fill reservoir.
Locate source of air leak and correct.
Replace hose.
Remove burrs or dirt.
Tighten.
Properly seat pressure plate against ring.