SECTION 4. Disassembly,Inspection,And Reassembly

3.Disassembly

STEP 1.

secure the steering hand pump body in a clean soft jaw vice.,do not over tighten the vice.Remove the fittings,remove and discard the o-rings.Make a note of the position of the sensing hose fitting.

STEP 4.

For pumps equipped with cross over check valves,mark position and remove spring, valve pins and balls.

IMPORTANT: Do not use a magnet to remove balls.

STEP 5. Use a screw driver to release the spiral retaining ring from the groove in the pump body.Remove the spiral retaining ring,seal bushing,o-ring and seal ring.Remove dust seal from seal bushing.

STEP 6. Remove thrust washer,thrust bearing and thrust washer.

STEP 7.

STEP 2. Cover bolt

End cap

O-ring

Cover bolt

Put alignment marks (A) on body, plate, stator and end cap.Remove bolts and end cap,remove and discard o-ring.

STEP 3. Remove spacer,stator and rotor,remove and discard o-ring.Remove drive shaft and plate.Remove and discard o-ring.Remove the pump from the vice and place on a clean work surface.

Turn spool and sleeve assembly until pin is parallel to the hydraulic fitting mounting face.Remove spool and sleeve assembly from the body.

STEP 8. Remove pin from the spool and sleeve assembly.Remove spool from sleeve and remove centering springs

O-ring Spacer Gyrotor

Remove plug and install a machine screw into the threaded end of check valve seat.Pull check valve seat from the pump body and remove and discard o-rings from check valve seat.Remove check valve ball and check ball retainer.DO NOT remove the relief valves(if equipped) from the pump body.

NOTE:DO NOT remove the check valve from the pump body inlet port(D)

Assembly

NOTE:During assembly lubricate at all parts with clean transmission oil.

Lubricate and install new o-rings onto check valve seat.Install check ball retainer,check ball and check valve seat into the pump body.Make sure the threaded end of check valve is facing outward.Install and tighten plug to a torque of 11Nm(100 lb in).

STEP 11.

STEP 10.

Adaptor screw Ball

Install spool into sleeve.Make sure the alignment marks are aligned.

IMPORTANT: Heat from your hands may expand spool preventing the spool being installed.

Allow the spool to cool and repeat STEP 11. STEP 12.

Install the centering spring installer through the slot in the sleeve assembly.Arrange the four centering springs as shown,install one end the springs into the slot in the centering spring installer. Make sure the notched side of the springs is towards the sleeve assembly. Compress by hand the the other end of the springs and push into the sleeve assembly.

NOTE: Make sure the centering spring notches locate correctly into the sleeve.

STEP 13

STEP 15. Pin install pin into sleeve assembly and install sleeve into the pump body.

NOTE:Heat from your hands may expand spool and sleeve assembly,preventing the assembly being installed,DO NOT use force to install spool and sleeve assembly.Allow the assembly to cool and repeat STEP 13.

STEP 14.

Install thrust washer,thrust bearing and thrust washer onto spool.lubricate a new o-ring and seal ring.install o-ring into the pump body and install seal ring onto spool.Install the seal bushing with a slight twisting motion,use a soft faced hammer and tap the bushing into position against the thrust washer.

Install spiral retaining ring into the the groove in the pump body.Use a screwdriver to make sure the spiral retaining ring is located correctly into the groove in the pump body.

STEP 16.

Carefully turn sleeve assembly until pin is parallel to hydraulic fitting mounting face as shown.

For pumps equipped with cross over check valves,install balls,valve pins and springs in the position noted in STEP 4.

STEP 18

Lubricate and install new o-ring into the groove in pump body.Install plate,align marks made in STEP 2,make sure the o-ring groove in plate is facing outwards.

STEP 19

With pin parallel to fitting mounting face.install drive shaft,make sure the slot in drive shaft locates onto pin.

STEP 20 install rotor onto drive shaft.Make sure one of the rotor teeth is aligned with the connector mounting face.Lubricate and install a new oring into the groove in plate.Align the marks made in STEP 2, and install stator.Make sure the o-ring groove in stator is facing outwards.

NOTE: Pin must remain parallel with the connector mounting face as shown.

IMPORTANT: If rotor is installed incorrectly.the steering hand pump will operate as a motor when installed onto the tractor and the engine is running.The steering wheel will rotate continually which may cause damage and injury.

STEP 21

Install spacer into rotor.Lubricate and install a new o-ring into the groove in stator.

STEP 22

Align the marks made in STEP 2,and install the end cap.Install and evenly tighten the torx hand screws in two stages to a torque of 17 Nm(12 lb ft) then to 25 to 30 Nm (19 to 22lb ft) in the sequence shown.

NOTE: The torx head bolts must by dry and clean of oil.

STEP 23

Install a new dust seal into seal bushing.

STEP 24

Install clean transmission oil into the return port and supply port.Cover all the ports with a clean cloth and slowly turn the pump input shaft clockwise and counterclockwise.

STEP 25

Repeat STEP 24 until the steering hand pump is primed of oil.

STEP 26

Lubricate new o-rings with clean transmission oil. Install the o-rings onto the fittings.Install and tighten the fittings.