Figure 4-13. Hydraulic Pump Control.
(1)
Using appropriate wrenches, loosen the adjustment screw locknut and remove the adjustment screw. The
control spring and spring retainer can now be removed from the cavity.
(2)
Using an internal hex wrench remove the threaded plug from the opposite end of the control and remove
the control spool.
(3)
Flush the control cavity with clean solvent and wash all parts in solvent and air dry. Examine spool and
cavity surfaces for nicks or scratches and replace any parts found to be defective.
(4)
Replace spring and spring retainer in cavity from adjustment end and reinstall adjustment screw and
locknut. Install control spool in opposite end of control and install plug. Insure that orientation of spool is
correct.
(5)
Reinstall control on pump housing replacing o-ring and control gasket as part of the procedure.
b.
Thoroughly clean and inspect all parts. Examine for nicks, burrs, scoring discoloration, etc. Replace all
damaged parts.
c.
Cleaning parts by using a solvent wash and air drying is adequate, providing clean solvent is used. As with any
precision equipment, the internal mechanism and related items must be kept free of foreign materials and
chemicals.
d.
It is recommended that all gaskets and o-rings be replaced. All gasket sealing surfaces must be cleaned prior to
installing a new gasket. Lightly lubricate all o-rings with clean petroleum jelly prior to assembly.
4-6.3.3 Assembly. (Figure 4-12)
a.
Press the bearing (29) onto the shaft (30). The bearing must be pressed on until it rests on the shoulder of the
shaft.
b.
Press new bearing race (29) into the housing (23) if it was previously removed or if a new bearing cone was
installed on the shaft. Insert the shaft and bearing (29, 30) into the housing (23).
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