Steering Specifications; Steering Gear Adjustment Preload Torques - Hummer H1 Service Manual

8-44 Steering System
POWER STEERING SYSTEM FLUSHING
The power steering system can be flushed but only when the
fluid does not contain metal particles, foreign material, or de-
bris from a gear or pump failure. Flushing is recommended
only under the following circumstances:
• incorrect fluid added to system
• system filled with incorrect fluid
• water in the fluid
• burned, overheated fluid
Flushing Procedure
1. Raise front wheels just enough for them to turn freely.
2. Disconnect fluid return line at pump. Then plug pump
return port with rubber cap and hose clamp.
3. Position and secure pump return line in drain pan.
4. Have container of fresh power steering fluid handy. Pump
reservoir will need refilling as old fluid is pumped into
drain pan.
5. Start and run the engine at curb idle speed.
6. Have helper slowly turn steering wheel back and forth
about 3/4 turn in each direction.
7. Continue procedure until only fresh fluid comes out of
return line.
8. Stop engine, reconnect pump return line, and add power
steering fluid as needed.
9. Purge air from system. Refer to procedure in this section.
10. Stop engine and check fluid level and condition. Repeat
flushing procedure if any old fluid is still evident in
reservoir fluid.
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STEERING SPECIFICATIONS

Recommended fluid is Dextron III.

Steering Gear Adjustment Preload Torques

Wormshaft bearing ..................... 6 to 15 lb-in (0.7 to 1.7 N•m)
Pitman shaft overcenter .............. 6 to 10 lb-in (0.7 to 1.1 N•m)
NOTE: Overcenter preload is in addition to wormshaft bearing
preload. For example, overcenter preload should produce a
combined final torque ranging from 12 to 25 inch-pounds.
Torque Specifications
Adjuster Plug Locknut................................. 80 lb-ft (109 N•m)
Adjuster Screw Locknut ................................ 35 lb-ft (47 N•m)
Ball Guide Clamp Bolts................................. 36 lb-ft (49 N•m)
Pressure Hose Fittings (at gear)..................... 25 lb-ft (34 N•m)
Rack Piston Plug........................................ 111 lb-ft (150 N•m)
Side Cover Bolts............................................ 44 lb-ft (60 N•m)
Steering Pump Flow Rates and Operating
Pressures
Minimum Flow Rate In Gallons/Liters Per Minute = 1.32 gpm
(5.0 liters/min) @ 465 rpm
Maximum Flow Rate In Gallons/Liters Per Minute = 3.1 to 3.5
gpm (11.7 to 13.2 liters/min) @ 1500 rpm
Minimum Pump Output Pressure 1200 psi (8274 kPa)
Maximum Pump Output Pressure: 1,475 - 1,515 psi (10,170 -
10,446 kPa)
NOTE: Pump output pressures are controlled by the pump re-
lief valve setting
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