Komatsu ecot3 PC300LC-8 Shop Manual page 177

10 Structure, function and maintenance standard
2. When the arm is in neutral
Operation
Returning the lever to neutral reduces the pilot
q
pressure from the PPC valve to 0 kg/cm
q The pressurized oil that has flowed and been
drained through orifice (a) in valve (2) is closed
by pilot piston (1).
q The holding pressure on the arm bottom side
works on the difference between areas (S2)
and (S1) of valve (2) to the right.
q Valve (2) is closed by the total of this force and
the force of spring (3), so ports (A) and (B) are
shut off.
PC300, 350-8
2
.
SEN01994-01
51