Service manual

CHAPTER 9 8354/8404
9-12
D615-W02 May-2003
615W915A
615W914A
• As shown in the figure, a guide is attached at pop-
pet (6) and valve chamber D.C (damping chamber)
located at the bottom of the guide piston. Intake of
valve enable through sliding part of guide and clear-
ance of seat (5) to chamber and minimizes valve
vibration as damping effect of chamber.
• If oil pressure does not exceed the specified pres-
sure of the relief valve, relief valve will not operate
and oil flows from the hydraulic pump to the inlet of
hydraulic cylinder.
• As the oil pressure of circuit increases, that of damp-
ing chamber D.C. increases. If pressure exceeds
the specified valve and the spring tension, the valve
will open to flow oil through port T to transmission
case. If oil is discharged sufficiently and its pres-
sure is less than the specified, the valve will be
closed.
Relief valve setting
pressure
Engine speed
Oil temperature
16.2 ~ 17.2 Mpa
16.5 ~ 17.5 kgf/cm²
2.347 ~ 2.489 psi
Max.
40 ~ 60 °C
104 ~ 140 °F
(1) Adjusting Shim (4) Hydraulic Block Body
(2) Adjusting Shim (5) Seal
(3) Plug (6) Poppet
7. RELIEF VALVE (HYDRAULIC BLOCK)
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