JLG 340AJ Service Manual - Manual (Page 194)

SECTION 5 - HYDRAULICS
5-36 – JLG Lift – 3121259
Charge Pressure Relief Valve
The charge pressure relief valve maintains charge pressure at a
designated level above case pressure.The charge pressure
relief valve is a direct acting poppet valve that opens and dis-
charges fluid to the pump case when pressure exceeds a des-
ignated level. This level is nominally set with the pump
running at 1800 min
-1
(rpm). For external charge flow, the
CPRV is set with a flow of 30 l/min [8 US gal/min]. In forward or
reverse, charge pressure will be slightly lower than in neutral
position. The model code of the pump specifies the charge
relief setting.
Typically charge pressure increases from 1.2-1.5 bar per 10 l/
min [17.4-21.8 psi per 2.64 US gal/min].
MA
L2 MB
C2 C1
M4
M5
A
M3
B
S
E
F
L1
X
M14
DRIVE
PUMP
X3
Figure 5-27. Drive Pump Hydraulic Schematic
Figure 5-28. Charge pressure relief valve