Disassembly, Inspection and Assembly

Disassembly

Fig. 7 Disassembled view of hydraulic pump:

Refer to Fig. 7 when overhauling hydraulic pump.
1. Remove Hydraulic pump as described under REMOVAL/INSTALLATION.
2. Remove suction port union and wire clamp.
3. Mount rear housing in a vise.
4. Remove solenoid valve and O-rings from solenoid valve and rear housing.






5. Using special service tool No. 09278-54012 or equivalent, remove pulley nut by turning it clockwise, Fig. 8.






6. Using special service tool No. 09286-46011 or equivalent, remove pulley, Fig. 9.
7. Remove five front housing bolts, then using a plastic faced hammer, tap out front housing and remove O-ring from casing.
8. Remove front thrust washer, driveshaft, drive and driven rotors and rear thrust washer.
9. Remove casing and O-ring from rear housing.
10. Using a 10mm hexagon wrench remove end plug, spool valve, compression spring and spool sleeve, then remove O-ring from end plug.

Inspection
1. Using a cleaner and compressed air, clean all disassembled parts. Thoroughly clean oil passages of rear housing. Oil passage A includes a filter which should be cleaned carefully, Fig. 10.
2. Coat spool valve with power steering fluid, then check that it falls smoothly into spool sleeve by its own weight.






3. Close one of the holes on spool valve and apply 57-71 psi of compressed air into the opposite side, Fig. 11. If air does not come out of end hole, replace spool valve as a set.
4. Using a vernier calipers, measure free length of compression spring. Free length should be 1.803 inch. If free length is not as specified, replace compression spring.
5. Install casing and rotors to rear housing with dot mark of rotors facing upward.






6. Remove one side of rotor, then using a thickness gauge and precision straightedge, measure side clearance between rotor and precision straightedge, Fig. 12. Side clearance of drive rotor should be .0008 inch and Side clearance of driven rotor should be .0012 inch. Maximum side clearance of drive rotor should be .0012 inch and maximum side clearance of driven rotor should be .0016 inch.
7. If clearance is greater than maximum, replace rotors as a set. If necessary, replace housings.






8. Using a feeler gauge, measure clearance between driven rotor and casing, Fig. 13. Body clearance should be .0020-.0035 inch. If clearance is greater than .0039 inch, replace rotors as a set. If necessary, replace casing.






9. Using a feeler gauge, measure clearance of all six drive rotor tips between drive and driven rotors, Fig. 14. Tip clearance should be .0008 inch. If clearance is greater than .0012 inch, replace rotors as a set.
10. Remove rotors and casing from rear housing.






11. Using a caliper gauge, measure bushing inside diameter on housing. Bushing inside diameter should measure .6693-.6713 inch. Using a micrometer, measure driveshaft diameter. Shaft diameter should measure .6681-.6685 inch, Fig. 15.
12. Subtract driveshaft diameter measurement from bushing inside diameter measurement. Clearance should be .0008-.0031 inch. If clearance is greater than .0031 inch, replace shaft. If necessary, replace housings.

Assembly






1. Using a hammer and special service tool No. 09631-10030 or equivalent, tap out oil seal, Fig. 16.
2. Using a hammer and 22mm socket wrench, tap in new oil seal until its surface is flush with housing edge.
3. Apply fluid to all sliding and rotating surfaces of pump.






4. Align small hole of spool sleeve with hole of rear housing, and insert spool body into rear housing, Fig. 17.
5. Insert compression spring and spool valve into rear housing, install new O-ring to end plug and temporarily install end plug.






6. Insert a .19 inch straight pin through holes of rear housing and spool sleeve, Fig. 18. Torque end plug to 14 ft. lbs., then remove straight pin.
7. Install new O-ring to rear housing groove. If rubber from O-rings adheres to O-ring installation location, replace casing.
8. Align pin hole of casing with straight pin on rear housing and install casing.
9. Install rear thrust washer, driven and drive rotors, driveshaft and front thrust washer.
10. Install new O-ring to casing groove, then align pin holes of front housing with straight pin. Install front housing and five bolts and torque bolts to 15 ft. lbs.
11. Ensure driveshaft rotates smoothly without abnormal noise, then temporarily install pulley nut and check rotating torque. Rotating torque should be 2.6 inch lbs.
12. Slide pump pulley onto driveshaft and measure clearance between pulley end and driveshaft end. Standard clearance should be .051-.067 inch and minimum clearance should be .039 inch. If clearance is less than minimum, replace pulley.
13. Using special service tool No. 09278-54012 or equivalent, torque pulley nut to 43 ft. lbs.
14. Install new O-rings to solenoid valve and rear housing groove, then install solenoid valve. Torque solenoid valve to 28 ft. lbs.
15. Install wire clamp to rear housing.
16. Install O-ring to port union and install port union with bolt. Torque port union bolt to 10 ft. lbs.
17. Install Hydraulic pump as described under REMOVAL/INSTALLATION.