Steering System - Power Buick Century V

DESCRIPTION & OPERATION

Note. Some vehicles are equipped with Variable Effort Steering (VES) system, identified by a solenoid on the power steering pump at the pressure line outlet. See the STEERING SYSTEM - VARIABLE EFFORT article in this section.

RACK & PINION ASSEMBLY

Pump pressurizes fluid and sends it through the pump's flow control valve to the pinion and valve on the rack and pinion assembly. (Scheme 1) Pinion and valve direct fluid to either side of the piston and rack, depending on turning direction of steering wheel. Piston and rack converts hydraulic pressure into linear force, reducing turning effort.

(3.4L)

Power steering pump is designated as CB series or TC series. (Scheme 4)and (Scheme 5). These units are constant displacement vane-type pumps. Some pump applications have remote fluid reservoirs to enable different pump mounting locations for engines with or without A/C compressors. When pressure exceeds set limits, a flow control pressure relief valve opens, allowing fluid to return to the inlet side of the pump.

SERVICE PRECAUTIONS

Observe the following precautions when servicing air bag system

1. Disable air bag system before attempting any repairs to steering column or components. Refer to «DISABLING & ACTIVATING AIR BAG SYSTEM»(/buick/century/v-1982-1996/remont/manual-power-steering/#steering-system-power__disabling-activating-air-bag-system) .
2. After disabling air bag system, Diagnostic Energy Reserve Module (DERM) retains back-up voltage for about 10 minutes. To avoid accidental air bag deployment, wait at least 10 minutes after disabling air bag system before working on vehicle components.
3. Always wear safety glasses when working around air bag system.
4. Always carry a live (undeployed) air bag with trim cover facing away from your body. This minimizes the chance of injury if air bag accidentally deploys.
5. Place a live (undeployed) air bag on a bench or other surface with trim cover facing up, away from surface. This will reduce motion of air bag if it accidentally deploys.
6. Never probe air bag inflator module connectors. Air bag may accidentally deploy.
7. Never attempt repair of any air bag system components. Replace any faulty components as required.

DISABLING & ACTIVATING AIR BAG SYSTEM

TROUBLE SHOOTING

Refer to TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.

FLUID TYPE

Use GM Power Steering Fluid (1050017) or an equivalent meeting GM Specification No. 9985010. Failure to use proper fluid will cause hose and seal damage, resulting in fluid leaks and damage to pump and/or rack and pinion assembly .

CAPACITY

POWER STEERING FLUID CAPACITY

FLUID LEVEL CHECK

Fluid level is indicated by marks on reservoir dipstick. Ensure fluid level is at FULL COLD mark when fluid is about 70°F (21°C). Ensure fluid level is at FULL HOT mark when fluid is at operating temperature of about 170°F (77°C).

HYDRAULIC SYSTEM BLEEDING

Note. If air is introduced into hydraulic system during servicing, bleed system. Aerated fluid, which appears Light Tan in color, results in poor steering performance and may cause pump damage.

1. Turn ignition off. Raise and support vehicle with wheels off ground. Turn wheels fully to left. Add power steering fluid to FULL COLD mark on dipstick. Turn wheels from side to side several times, but DO NOT touch steering stops. Add fluid, if necessary, to maintain level at FULL COLD mark.
2. Start engine. With engine idling, recheck fluid level. Add fluid, if necessary, to bring level to FULL COLD mark. Return wheels to center position. Lower vehicle. Continue to run engine for 2-3 minutes.
3. Road test vehicle. Check for leaks. Ensure fluid level is at FULL HOT mark when fluid stabilizes at operating temperature.

POWER STEERING PUMP BELT (SERPENTINE BELT) ADJUSTMENT

1. Serpentine belt tension is maintained by automatic tensioner. Ensure tensioner indicator mark on movable portion of tensioner is within limits of slotted area on stationary portion of tensioner. Any reading outside these limits indicates a worn belt or defective tensioner.
2. If installing NEW belt, ensure tensioner indicator is within limit marks. If not, replace defective tensioner.
3. If installing original belt, ensure belt's operating length and/or tensioner's operating range marks are not out of limits. Replace belt or tensioner as necessary.

RACK BEARING PRELOAD ADJUSTMENT

1. Raise and support vehicle. Turn front wheels to straight-ahead position. Loosen adjuster plug lock nut. (Scheme 1) Turn adjuster plug clockwise until it bottoms in housing. Back off adjuster plug 50-70 degrees (about one flat).
2. While holding adjuster plug stationary, tighten adjuster plug lock nut to specification. See «TORQUE SPECIFICATIONS»(/buick/century/v-1982-1996/remont/manual-power-steering/#steering-system-power) table. Test drive vehicle, ensuring steering wheel returns to center after turning.

Scheme 1

TESTING

Note. Incorrect fluid level, belt tension and idle speed, as well as a damaged pump pulley, can affect test results. If any of these conditions exists, correct them before testing power steering system.

PRESSURE TEST

1. Disconnect high pressure line from power steering pump. Connect Power Steering Pressure Tester Kit (J-5176-D), or Power Steering Analyzer (J-25323) with Adapter (J-28579), between high pressure line and power steering pump using spare high pressure hose. Completely open tester valve.
2. Run engine until fluid reaches operating temperature. Stop engine. Check fluid level. Add fluid if necessary. Start engine. With valve open and engine idling, pressure should be about 80-125 psi (5.6-8.8kg/cm 2 ). If pressure exceeds about 200 psi (14.1 kg/cm 2 ), stop engine and check for restrictions in hoses. CAUTION: To prevent pump damage, DO NOT hold gauge valve closed for more than 5 seconds.
3. If pressure is less than about 80-125 psi (5.6-8.8 kg/cm 2 ), close valve fully for less than 5 seconds and then open it. Repeat process 2 times, noting highest pressure displayed each time valve is closed. If readings are about 1000-1250 psi (70.3-87.8 kg/cm 2 ) or greater, and are within 50 psi (3.5 kg/cm 2 ) of each other, go to step 6).
4. If readings are as specified but are not within 50 psi (3.5 kg/cm 2 ) of each other, flow control valve is sticking. Remove valve but do not disassemble it. Clean valve using crocus cloth or fine hone. Flush system if dirty. Install valve. Recheck pressure. If pressure is as specified, go to step 6).
5. If readings are within 50 psi (3.5 kg/cm 2 ) of each other but are not within specification, replace flow control valve and retest system. If readings are still low, check pump rotor and vanes for wear. Replace complete pump assembly if worn.
6. With valve open, turn steering wheel from stop to stop. Record highest pressure with wheels at both stops. If highest pressure is not equal to highest pressure recorded in step 3), rack and pinion assembly is leaking internally. Repair or replace assembly. If pressures are equal, no problem exists. Go to next step.
7. Turn engine off. Remove tester. Reconnect high pressure hose to pump. Check fluid level. Bleed hydraulic system. Refern to «HYDRAULIC SYSTEM BLEEDING»(/buick/century/v-1982-1996/remont/manual-power-steering/#steering-system-power__hydraulic-system-bleeding) under LUBRICATION.

FLOW RATE TEST

1. Connect Power Steering Analyzer (J-25323-A) into system. Open analyzer valve fully. Run engine until fluid reaches operating temperature. Check fluid level. Add fluid if necessary. Record pressure and flow rate.
2. Close valve partially until pressure builds to 700 psi (49.2 kg/cm 2 ), and then record flow rate. Subtract flow rate from that measured in step 1). If flow rate drops more than one gallon (3.8L) per minute, replace ring, rotor and vanes in pump.
3. Increase engine speed to 1500 RPM and read flow rate. Subtract flow rate from that measured in step 1). If difference between flow rates varies more than one gallon (3.8L) per minute, remove and clean flow control valve.
4. Turn steering wheel from stop to stop. Flow rate should drop to less than one gallon (3.8L) per minute at each stop. If flow rate is within specification, check rack and pinion assembly for leakage.

REMOVAL & INSTALLATION

Removal

Raise and support vehicle. Remove cotter pin and castle nut from outer tie rod end. Loosen outer-to-inner tie rod lock nut. Using Steering Linkage Puller (J-24319-01), separate outer tie rod end from steering knuckle. Remove outer tie rod end from inner tie rod, noting number of turns required to remove.

Installation

Install outer tie rod end with same number of turns as when removed. Tighten outer-to-inner tie rod lock nut to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure. Tighten tie rod end castle nut to specification. Install NEW cotter pin at castle nut. DO NOT back off nut to install cotter pin. Adjust toe-in as necessary.

Remove outer tie rod. See OUTER TIE ROD R & I . Remove outer-to-inner tie rod lock nut. Remove outer boot clamp. Cut off and discard inner boot clamp. When replacing both rack boots, mark location of breather tube (if equipped) to rack for installation reference. Remove breather tube. DO NOT remove breather tube if only replacing one boot. Slide boot from inner tie rod.

1. Place NEW inner clamp on boot. Install breather tube (if removed), aligning tube as marked during removal. Install boot. If necessary, apply thin coat of grease to inner tie rod (except threads), and to boot clamping area on housing to aid installation. Ensure boot is not twisted or out of shape. Ensure breather tube is in proper notch position in boot.
2. Crimp inner clamp using Banding Tool (J-22610). Install outer clamp. Install outer tie rod end. Tighten outer-to-inner tie rod lock nut to specification. See «TORQUE SPECIFICATIONS»(/buick/century/v-1982-1996/remont/manual-power-steering/#steering-system-power) table. To complete installation, reverse removal procedure. Adjust toe-in as necessary.

Remove serpentine drive belt. It may be necessary to remove or relocate power steering pump for pulley removal clearance (leave hoses connected to pump if possible). For pump removal procedures, see POWER STEERING PUMP R & I . Install Pulley Remover (J-25034-B) on pulley hub at pump shaft. While holding remover body with wrench, turn center bolt clockwise to draw/pull pulley off pump shaft.

Using Pulley Installer (J-25033-B), press pulley onto shaft until face of pulley hub is even with end of shaft. If pump was removed from engine, DO NOT use a press to install pulley. If pump was removed from bracket, install pump. Fill and bleed hydraulic system. See HYDRAULIC SYSTEM BLEEDING under LUBRICATION.

Remove drive belt. Remove belt tensioner (if necessary). Remove pump pulley. See POWER STEERING PUMP PULLEY R & I . Disconnect pressure line from pump and plug all openings. On vehicles with pump adapter, disconnect return line from pump adapter using Quick Connect Separator (J-36391). On all vehicles, remove pump mounting bolts. Remove pump adapter (if equipped). Remove pump.

To install, reverse removal procedure. Fill and bleed hydraulic system. See HYDRAULIC SYSTEM BLEEDING under LUBRICATION.

1. Install a plug into return tube to prevent metal chips from entering pump. Using a 9/16" x 12 tap, a 9/16" x 12 nut and five 5/8" washers, screw tap into tube, and slide washers over end of tap and onto pump. Install nut onto tap, and turn nut to draw tube out from pump body. (Scheme 2)
2. To install, coat end of return tube with Loctite Solvent (75559) and Loctite Adhesive (290). Press tube into housing until it bottoms.

Scheme 2

Remove power steering pump (if necessary to access rear of pump). See POWER STEERING PUMP R & I. Remove pressure line fitting from pump. (Scheme 3) Remove "O" ring, flow control valve assembly and flow control spring. To install, reverse removal procedure. Tighten pressure line fitting to specification. See TORQUE SPECIFICATIONS table.

Scheme 3

Remove power steering pump (if necessary to allow clearance for pulley removal). See POWER STEERING PUMP R & I . Remove pump pulley. See POWER STEERING PUMP PULLEY R & I . Protect pump shaft with shim stock. Cut seal metal housing with small chisel to ease seal removal. Use screwdriver to pry seal out of body. Remove and discard seal. Remove shim stock from shaft.

Lubricate new seal with power steering fluid. Using Shaft Seal Installer (J-7728) or a suitable size deep socket, drive seal into housing until it bottoms. Install pulley on pump. Install pump to bracket (if removed).

RACK & PINION ASSEMBLY R & I

Removal (2.2L)

1. Disconnect pressure and return lines from rack and pinion assembly. Remove pressure line retaining clips from rack. Support engine from top using Engine Support Fixture (J-28467-A). Raise and support vehicle. Remove front wheels. CAUTION: Failure to disconnect steering shaft coupling from rack and pinion assembly shaft may damage these components, possibly resulting in loss of steering control after installation. DO NOT start engine with hoses removed, as severe pump damage will result.
2. Remove cotter pins and castle nuts from outer tie rod ends. Separate tie rod ends from steering knuckles using Steering Linkage Puller (J-24319-01). Remove intermediate shaft lower coupling pinch bolt. Disconnect intermediate shaft lower coupling from rack and pinion assembly stub shaft.
3. Remove left engine splash shield. Loosen nuts securing engine and transaxle mounts to frame. Remove firewall reinforcement bracket bolts. Support engine frame at rear with jack. Loosen, but DO NOT remove, front engine retaining bolts. CAUTION: DO NOT lower rear of engine frame too far. Engine components near firewall may be damaged.
4. Remove rear engine frame retaining bolts. Lower rear engine frame for access to rack and pinion assembly. Remove rack and pinion assembly mounting nuts and bolts. Pull assembly out through left wheel opening.

To install, reverse removal procedure. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS table. Fill and bleed hydraulic system. See HYDRAULIC SYSTEM BLEEDING under LUBRICATION. Adjust toe-in as necessary.

Removal (3.1L)

1. Support engine from top using Engine Support Fixture (J-28467-A). Raise and support vehicle. Remove front wheels. Loosen nuts securing engine and transaxle mounts to frame. CAUTION: Failure to disconnect steering shaft coupling from rack and pinion assembly shaft may damage these components, possibly resulting in loss of steering control after installation. DO NOT start engine with hoses removed, as severe pump damage will result.
2. Remove steering column intermediate shaft lower coupling pinch bolt. Disconnect steering column intermediate shaft lower coupling from rack and pinion stub shaft. CAUTION: DO NOT lower rear of engine frame too far. Engine components near firewall may be damaged.
3. Support and lower engine frame at rear for access to rack and pinion assembly. Remove rack and pinion assembly heat shield. Remove pressure line retaining clips from rack. Remove cotter pins and castle nuts from outer tie rod ends. Separate tie rod ends from steering knuckles using Steering Linkage Puller (J-24319-01).
4. Disconnect pressure and return lines from rack and pinion assembly. Remove rack and pinion assembly mounting nuts and bolts. Pull assembly out through left wheel opening.

To install, reverse removal procedure. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS table. Fill and bleed hydraulic system. See HYDRAULIC SYSTEM BLEEDING under LUBRICATION. Adjust toe-in as necessary.

Disassembly

1. Remove hydraulic union fitting from pump. (Scheme 4) Remove "O" ring, flow control valve assembly and flow control spring. Using punch in access hole, remove end cover retaining ring. Press gently on pulley end of shaft to remove end cover, "O" ring, pressure plate spring and pressure plate.
2. Remove shaft sub-assembly consisting of remaining components. Disassemble sub-assembly, noting component location for reassembly reference. Cut shaft seal with a small chisel. Remove and discard shaft seal.

Inspection

Inspect pump ring, vanes, thrust plate and shaft for scoring, pitting or chatter marks. Replace worn or damaged parts.

Reassembly

1. Lubricate new shaft seal, "O" rings and all other components with power steering fluid. Drive new seal into housing with suitable socket. Assemble shaft sub-assembly with components in original locations. Ensure counterbore in center of pump rotor faces pump pulley.
2. Install shaft sub-assembly. Install remaining components. Press end cover in far enough to snap retaining ring into place. Install flow control valve assembly and related components. Tighten hydraulic union to specification. See «TORQUE SPECIFICATIONS»(/buick/century/v-1982-1996/remont/manual-power-steering/#steering-system-power) table.

Scheme 4

1. Remove pump pulley. See «POWER STEERING PUMP PULLEY R & I»(/buick/century/v-1982-1996/remont/manual-power-steering/#steering-system-power) under REMOVAL & INSTALLATION. Remove shaft bearing retaining ring. (Scheme 5) Pull shaft and bearing assembly out of pump. If removing bearing from shaft, measure and record clearance (if any) between shaft shoulder and bearing inner race. (Scheme 6) Pry shaft seal from housing.
2. Remove flow control fitting from pump. (Scheme 5) Remove "O" ring, flow control valve assembly and flow control spring.
3. Using a small punch in access hole, remove thrust plate retaining ring. Using a press and 5/8" piece of bar stock, press against pressure plate hub until thrust plate is removed. Remove "O" ring, pump ring, pump rotor, vanes and 2 dowel pins.
4. Remove pressure plate using press (if necessary). Remove "O" ring from pressure plate. Remove dowel pin from housing. Remove "O" ring from sleeve. Working from pulley side of housing, drive out sleeve with a punch.

Clean all parts in power steering fluid. Inspect pressure plate, vanes, pump ring, drive shaft and bearing for scoring, pitting or chatter marks. Replace worn or damaged parts.

1. Press new sleeve assembly into housing. Install new lubricated "O" ring into groove in sleeve. Install dowel pin into housing. Install pressure plate spring. Install new, lubricated "O" ring into groove in pressure plate.
2. Mark spot on top of pressure plate directly over dowel pin hole in plate to help align hole with dowel pin. Install pressure plate into housing, ensuring pin engages hole in pressure plate. Install 2 pump ring dowel pins.
3. Install pump rotor with counterbore (larger diameter of center bore) facing pulley end of housing. Insert pump vanes into rotor slots. With identification marks on pump ring facing upward, install pump ring over dowel pins. Install new, lubricated "O" ring into housing groove.
4. Install thrust plate, ensuring dimples in thrust plate align with mounting holes in housing, and thrust plate holes engage pump ring dowel pins. Press thrust plate into housing far enough to install retaining ring.
5. Press shaft bearing onto shaft until clearance between inner race and shoulder is same as clearance recorded before removal. (Scheme 7) Slide shaft and bearing assembly into housing, rotating assembly to align splines of shaft and rotor. Install bearing retaining ring with beveled side down, indicated by position of large lug on ring. (Scheme 7) Install pulley on pump.

Scheme 5

Scheme 6

Scheme 7

RACK & PINION

Note. Perform overhaul procedures with rack and pinion assembly removed from vehicle. See RACK & PINION ASSEMBLY R & I under REMOVAL & INSTALLATION.

PINION & VALVE ASSEMBLY

1. Remove adjuster plug lock nut, adjuster plug, adjuster spring and rack bearing. (Scheme 1) Remove retaining ring from stub shaft. Remove dust cover from bottom of pinion and valve assembly housing. While holding stub shaft stationary with 14-mm wrench, remove lock nut from bottom of shaft.
2. Center rack in housing. For reassembly reference, mark location of stub shaft notch on housing, and measure distance between ends of tie rod boot. (Scheme 8)
3. Using an arbor press, press threaded end of pinion and valve assembly until assembly is loosened, but DO NOT remove. Mark second location of stub shaft notch on housing for reassembly reference.
4. Remove stub shaft dust seal, stub shaft seal and stub shaft bearing annulus (race) assembly. Remove pinion and valve assembly with retaining ring and valve body rings attached. Carefully remove valve body rings from pinion and valve assembly.

Scheme 8

Clean valve body ring grooves. Check pinion and valve assembly drive pin. If pin is broken, replace rack and pinion assembly.

1. Apply grease to ring grooves. (Scheme 9) Install new valve body rings on pinion and valve assembly, ensuring split tabs are engaged and staggered. Use care not to cut rings during installation. Apply grease to valve body rings.
2. Install pinion and valve assembly into Ring Protector (J-37090). (Scheme 10) Position valve assembly in ring protector so valve body is even with bottom of protector. Allow rings to rest inside ring protector for about 3 minutes so valve rings will size properly.
3. Using measurement taken during disassembly as a guide, center rack in housing. Clean and apply grease to housing bore. Ensure stub shaft bearing annulus (race) is not damaged and bearing is even with annulus. (Scheme 11)
4. Align notch on valve stub shaft with second mark made during disassembly. Using ring protector and Pinion Seal Installer (J-29822), push pinion and valve assembly into housing bore. DO NOT hammer or use excessive force. If assembly does not fully seat in housing, ensure valve body rings are not binding in bore.
5. After assembly is seated in bore, ensure notch in stub shaft and first mark on housing are aligned. While holding stub shaft to prevent damage to pinion teeth, install adjuster plug lock nut and tighten to specification. See «TORQUE SPECIFICATIONS»(/buick/century/v-1982-1996/remont/manual-power-steering/#steering-system-power) table.
6. Install dust cover. Install stub shaft bearing annulus assembly onto pinion and valve stub shaft. Install Seal Protector (J-29810) onto valve stub shaft. Apply a small amount of grease between stub shaft seal and stub shaft dust seal. Install seals over protector and into housing. Install retaining ring into groove in housing.
7. Lubricate stub shaft and dust seal area with grease. Coat rack bearing, adjuster spring and adjuster plug with grease and install into housing. With rack centered in housing, turn adjuster plug clockwise until it bottoms in housing, then back off 50-70 degrees (about one flat). Using an INCH-lb. torque wrench, check pinion torque. Maximum pinion preload torque is 16 INCH lbs. (1.8 N.m).
8. Install adjuster plug lock nut onto adjuster plug. While holding adjuster plug, tighten lock nut to specification. Install rack and pinion assembly. Fill and bleed the hydraulic system. Refer to «HYDRAULIC SYSTEM BLEEDING»(/buick/century/v-1982-1996/remont/manual-power-steering/#steering-system-power__hydraulic-system-bleeding) under LUBRICATION.

Scheme 9

Scheme 10

Scheme 11

1. Remove outer tie rod end from inner tie rod, noting number of turns required for removal. Remove hex jam nut from inner tie rod. Remove adjusting nut from inner tie rod. Remove outer boot clamp. Cut off and discard inner boot clamp. Mark location of breather tube (if equipped) for reassembly reference. Slide boot from inner tie rod.
2. Slide shock damper ring on inner tie rod assembly back toward rack. Place a wrench on flat side of rack to prevent turning. Place another wrench on flats of inner tie rod. Rotate inner tie rod counterclockwise until it separates from piston and rack. Remove shock damper ring.

1. Install shock damper ring. To prevent internal damage, hold rack with a back-up wrench during tie rod installation. Install inner tie rod onto rack. Tighten inner tie rod to specification. See the «TORQUE SPECIFICATIONS»(/buick/century/v-1982-1996/remont/manual-power-steering/#steering-system-power) table. Ensure inner tie rod pivots freely in all directions. Stake both sides of inner tie rod to flats on rack. (Scheme 12)
2. Ensure both stakes are okay by inserting a.010" (.25 mm) feeler gauge between rack and tie rod housing. Feeler gauge must not pass between rack and housing stakes.
3. To reassemble, reverse disassembly procedure. Apply grease to inner tie rod and housing before installing boots. Install outer tie rod end with same number of turns as when removed. Install new cotter pin at castle nut. DO NOT back off castle nut to install cotter pin. Adjust toe-in as necessary. Fill and bleed hydraulic system. See «HYDRAULIC SYSTEM BLEEDING»(/buick/century/v-1982-1996/remont/manual-power-steering/#steering-system-power__hydraulic-system-bleeding) under LUBRICATION.

Scheme 12

WHEEL ALIGNMENT

After performing appropriate service procedures, refer to WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES article in the WHEEL ALIGNMENT section.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• TROUBLE SHOOTING - BASIC PROCEDURES
• COMPUTER RELEARN PROCEDURES
• WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES
• DISABLING & ACTIVATING AIR BAG SYSTEM
• TORQUE SPECIFICATIONS
• HYDRAULIC SYSTEM BLEEDING
• SERVICE PRECAUTIONS
• RACK & PINION ASSEMBLY R & I