Figure 4D-3. Control Valve Operation (36Z725)
TROUBLE, CAUSE AND REMEDY CHART
Oil leaks at either end of spool.
Defective O-rings in valve body.
Spring-centered spools do not
return to neutral.
Clean system and valve.
Misalignment of operating linkage.
Check linkage for binding condition.
No motion, slow or jerky action of
Relief valve not properly set, or
Repair, clean and readjust.
stuck in base and/or worn.
Dirt or foreign particles lodged
Disassemble, clean and reassemble.
between relief valve control pop
pet and seat.
Spool not moved to full stroke.
No relief valve action (High
Small particle of dirt plugging
Remove relief valve and check
orifice in relief valve sub-
hole. If blocked, deer hole.