Wittke FEATHERWEIGHT, Maintenance Manual

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118
Hydraulic System
3. By using the pump lever, raise the body until the cylinders reach the end of their stroke.
4.
Check pressure while the body is held fully raised.
The pressure reading shall be at 2000 psi.
5.
Adjust the relief if necessary.
Turn the adjustment screw clockwise to increase the pressure and counterclockwise to decrease
it.
Arms Down Work Section
Designed to protect the arm hydraulic circuits, the Arms Down Work Section is equipped with a
work port relief valve in the arms down outlet port only and is factory preset to 1000 psi (± 150 psi).
This relief valve is non-adjustable.
Location
On the main hydraulic valve bank, on the front header of the body or on the left-hand side mid-
section body wall.
Main System Pressure Adjustment
As with all hydraulic systems, it may be necessary to periodically check and adjust pressure relief
settings.
N
OTE
: The system pressure should be 2500 psi (S
TAR
L
IGHT
™ and F
EATHERWEIGHT
™) or 2750 psi
(S
UPER
D
UTY
™).
N
OTE
: The following two procedures are used to adjust the main system pressure. The first one is for a
pneumatically-operated valve, the second one for an electrically-operated valve.
N
OTE
: 2 people are required to perform these procedures.
A) Pneumatically-Operated Valve
Pressure adjustment procedure:
1.
Remove the cap on the quick coupler located at the top of the main valve bank. Insert a 0-
4000 psi pressure gauge.
Warning!
Tampering with the Work Port Relief Valve may cause serious damage to the arms circuit
and void warranty.