Power Steering Pump: Service and Repair
REMOVAL2.5L MODEL
1. Remove ground cable from battery.
2. Remove pulley belt cover bracket.
3. Loosen lock bolt and slider bolt and remove power steering pump drive V-belt.
4. Disconnect connector from power steering pump switch.
5. Disconnect pipe C and suction hose from oil pump.
CAUTION: Do not allow fluid from the hose end to come into contact with pulley belt.
To prevent foreign matter from entering the hose and pipe, cover the open ends of them with a clean cloth.
6. Remove bolts which install power steering pump bracket.
7. Place oil pump bracket in a vise, remove two bolts from the front side of oil pump.
CAUTION: Do not place oil pump bracket directly in the vise; use soft pads and hold oil pump lightly to protect the pump.
8. Remove socket from oil pump.
9. Remove bolt from the rear side of oil pump.
10. Disassemble oil pump and bracket by inserting a screwdriver as shown in the figure.
DISASSEMBLY
NOTE: Oil pump for TURBO model and 3.0L model cannot be disassembled. If the oil pump is malfunctioning, replace the oil pump as an assembly.
1. Using ST, place oil pump in a vise and remove four bolts which secure rear cover.
ST 34199AE020 ATTACHMENT
2. Remove pressure plate.
3. Using a screwdriver, pry retaining ring off.
CAUTION: Do not remove cam ring, rotor, etc.
4. Install pressure plate.
5. Temporarily install rear cover to front casing.
6. Remove oil pump pulley.
7. Place oil pump in a vise.
CAUTION: Do not place oil pump directly in the vise, use soft pads and hold oil pump lightly to protect the pump.
8. Pry oil seal off using a screwdriver.
CAUTION: Be careful not to scratch inner surface of casing.
ASSEMBLY
1. Reassembly precautions
1. Whenever O-rings, oil seals, and snap rings are removed, they must be replaced with new ones.
2. Thoroughly wash parts and allow to dry. They must be kept free from cleaning oil and dust.
3. Reassembly procedure must be performed in clean place. Ensure that parts are kept away from waste threads or other dust particles.
4. Cleaning oil tends to stay inside the front casing. Remove it completely by blowing compressed air.
5. Ensure that parts are free from rust. (Use specified hydraulic oil for rust prevention after cleaning and drying.)
6. Reverse the sequence of disassembly procedures.
2. Apply grease to oil seal and inner surface of front casing (at bearing location).
CAUTION: Make sure that the front body internal surfaces are free from damage.
3. Temporarily install rear cover to front body.
4. Attach ST to front body. Using a press, install oil seal.
ST 34199AE030 INSTALLER
5. Install pump pulley to front body.
6. Using ST, place oil pump in a vise.
ST 34199AE020 ATTACHMENT
7. Remove rear cover.
8. Using 10-mm box wrench, tap retaining ring into shaft groove.
9. Install pressure plate as shown in the figure.
10. Apply specified hydraulic oil to O-rings and fit them into front casing and pressure plate.
11. Install seal ring to pressure plate.
12. With knock pin positions aligned, install rear cover.
Tightening torque:
27.5 Nm (2.8 kgf-cm, 20.3 ft. lbs.)
CAUTION: Loosely tighten bolts in the sequence (A), (B), (C), and (D) shown in figure. Then, tighten in the same sequence.
13. When reassembly procedures have been completed, turn shaft by hand to ensure it turns smoothly. If it binds or other unusual conditions are evident, disassemble again and check for foreign matter trapped on sliding surfaces and improper installation. Eliminate the cause of trouble.
14. Check followings.
- Excessive play in pulley shaft
- Ditch deflection of pulley
- Resistance to rotation of pulley
- Measurement of generated oil pressure.
INSTALLATION
2.5L MODEL
1. Install oil pump to bracket.
1. Place oil pump bracket in a vise. Tighten bushing using a 12.7 mm (1/2) type 14- and 21 mm box wrench until it is in contact with oil pump mounting surface.
CAUTION: Do not place oil pump bracket directly in the vise; use soft pads and hold oil pump lightly to protect the pump.
2. Tighten bolt which installs oil pump and switch bracket to bracket.
2. Install socket to oil pump.
3. Tighten bolts which install power steering pump bracket.
4. Interconnect pipes C and suction hose.
Tightening torque:
Joint nut 39.2 Nm (4 kgf-cm, 28.9 ft. lbs.)
CAUTION: If a hose is twisted at this step, the hose may come into contact with some other parts.
5. Connect connector to power steering oil pressure switch.
6. Install pulley belt to oil pump.
7. Check pulley belt tension.
8. Tighten lock bolt.
Tightening torque:
24.5 Nm (2.5 kgf-cm, 18.1 ft. lbs.)
9. Tighten bolt belt tension.
Tightening torque:
8 Nm (0.8 kgf-cm, 5.8 ft. lbs.)
10. Install pulley belt cover bracket.
11. Connect ground terminal of battery.
12. Feed the specified power steering fluid
CAUTION: Never start the engine before feeding the fluid; otherwise vane pump might be seized up.
INSPECTION
BASIC INSPECTION
Perform the following inspection procedures and repair or replace defective parts.
In accordance with the table, check all removed parts for wear and damage, and make repair or replacement if necessary.
SERVICE LIMIT
Make a measurement as follows. If it exceeds the specified service limit, replace the parts with new ones.
CAUTION: Fix oil pump on a vise to make a measurement. At this time, hold oil pump with the least possible force between two wood pieces.
Do not set outside of flow control valve or pulley on a vise; otherwise outside or pulley might be deformed. Select properly sized wood pieces.
1. Play of pulley shaft
2. Ditch deflection of pulley
Service limit:
1.0 mm (0.039 inch) or less
NOTE: Read the value for one surface of V ditch, and then the value for another off the dial.
3. Resistance to rotation of pulley
Service limit.
Maximum load;
9.22 N (0.94 kgf, 2.07 lb) or less
NOTE: A rather higher value may be indicated when pulley starts turning.
Measure the load during rotation and make a judgment.
HYDRAULIC PRESSURE
CAUTION: Be sure to complete all items aforementioned in "INSPECTION", prior to measuring hydraulic pressure. Otherwise, pressure can not be measured correctly.
Do not leave the valve of pressure gauge closed or hold the steering wheel at stop end for 5 seconds or more in any case, as the oil pump may be damaged due to long keep of these conditions.
Put cotton cloth waste at a place where fluid drops before pressure gauge is installed. Wipe off split fluid thoroughly after the measurement.
NOTE: Keep engine idling during the measurement.
1. REGULAR PRESSURE MEASUREMENT
1. Connect ST1, ST2 and ST3.
ST1 92511000 PRESSURE GAUGE
ST2 34099AC020 ADAPTER HOSE B
ST3 34099AC010 ADAPTER HOSE A
2. Disconnect pressure hose from the pump.
3. Using gasket (Part No. 34621AC021) and bolt (Part No. 34620AC010), install ST2 to the pump instead of pressure hose.
2.5L model:
3.0L model:
4. Disconnect pipe C form pipe (on gearbox side).
5. Install ST3 to pipe C.
6. Replenish power steering fluid up to specified level.
7. Open valve, and start the engine.
8. Measure regular pressure.
ST1 925711000 PRESSURE GAUGE
ST2 34099AC020 ADAPTER HOSE B
ST3 34099AC010 ADAPTER HOSE A
9. If it is not within the specified value, replace the troubled part caused by the symptoms; pipe or hose clogged, leaks from fluid line, and mix of foreign objects in fluid line.
2. Measure relief pressure.
1. Using STs, measure relief pressure.
2. Close valve.
3. Measure relief pressure.
T1 925711000 PRESSURE GAUGE
T2 34099AC020 ADAPTER HOSE B
T3 34099AC010 ADAPTER HOSE A
4. If it is not within the specified value, replace the oil pump.
3. Measure working pressure.
1. Using STs, measure working pressure.
2. Open valve.
3. Measure working pressure of control valve by turning wheel from stop to stop.
ST1 925711000 PRESSURE GAUGE
ST2 34099AC020 ADAPTER HOSE B
ST3 34099AC010 ADAPTER HOSE A
Service limit.
2.5L model 9,611 - 10,199 kPa (98 - 104 kgf/cm2, 1,394 - 1,479 psi)
TURBO model and 3.0L model 7,650 - 8,340 kPa (78.03 - 88.13 kgf/cm2, 1,109 - 1,209 psi)
4. If it is within the specified value, measure steering effort. If it is not within specified value, replace control valve itself or control valve and pinion as a single unit with new ones.