Removal and installation of fnr and nfpe modules, Charge relief valve, Shim adjustable charge relief valve components -45 – JLG 510AJ Service Manual User Manual
Page 265
SECTION 5 - HYDRAULICS AND HYDRAULIC SCHEMATICS
3121181
– JLG Lift –
5-45
Removal and Installation of FNR and NFPE Modules
1.
Clean pump and module housings.
2.
Remove four (4) screws retaining module to housing [4
mm Int. Hex], and remove module from pump housing.
3.
Remove O-rings from the control ports. Examine ports
for cleanliness.
4.
Clean sealing surfaces.
5.
Replace locator pin.
6.
Install new O-rings.
7.
Replace screws [4.7-6.1 Nm (3.5-4.5 ft-lb].
Removal and Installation of FNR and NFPE Control
Orifices
NOTE:
Future models may contain an orifice plate between mod-
ule and pump housing. This will take the place of the orifice
plugs beneath the servo piston cover.
1.
Remove servo piston cover.
2.
Remove orifice plug [1/8 in Int. Hex].
3.
Examine orifice and port for cleanliness.
4.
Install orifice plug [2.0-3.4 Nm (1.5-2.5 ft•lbf )].
Charge Relief Valve
The charge relief valve may be removed for cleaning and
installation of fresh O-rings. The pressure setting may be
changed. However, note that the setting will vary for different
charge flows which depends on charge pump size and pump
speed. The factory setting is set relative to case pressure at
1800 rpm. The actual charge pressure will vary at different
speeds.
SHIM ADJUSTABLE STYLE
1.
Remove the shim adjustable charge relief valve plug [1
in Hex] from the pump housing. Remove the O-ring
from the plug.
2.
Remove the spring and poppet from the housing.
3.
Do not alter the shims which may be installed between
the spring and valve plug, or interchange parts with
another valve. Inspect the poppet and mating seat in
the housing for damage or foreign material.
4.
If desired, the charge relief valve setting can be
changed. An approximate rule of thumb is 4 bar / 1.25
mm (58 psi / 0.050 in). The effective setting will vary.
To confirm the charge relief valve setting, measure
charge pressure (port M3) with the pump in stroke. The
charge pressure should level off when the relief setting
is reached.
1. Plug
2. O-ring
3. Shims
4. SpringT-Seal
5. Poppet
Figure 5-81. Shim Adjustable Charge Relief Valve
Components