3.137.6. DIRECTIONAL VALVE - MAINTENANCE INSTRUCTIONS (Continued).
All parts must be thoroughly cleaned and kept clean during inspection and assembly. Contamination in
the unit will cause excessive wear, leakage and decreased service life. Clean in accordance with
standard procedures for hydraulic parts. Do not use compressed air to dry parts unless the air is
completely filtered in order to remove water and contaminants.
Check that they are
clean and unobstructed.
Inspect for nicks and
Inspect for wear.
Inspect for scoring and wear. Minor
scratches can be removed with crocus
cloth. Do not round off sharp corners
of spool bands.
Inspect the body bore for scoring and
wear. If excessive wear or scoring is
evident on the spool, the body bore is
most likely damaged. Any excess clear-
ances between the spool and body will
increase the leakage of the valve. The
maximum clearance is 0.0012 inch