Gravely 950001, Maintenance Manual

Page: 52 / 66

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With the engine running at normal operating speed
select the Crowd function. When the cylinder is fully
extended continue to hold the lever in the Crowd
position. The pressure gauge should read 2950 psi. If
the pressure setting requires adjustment, turn the
wrench clockwise to increase pressure or
counterclockwise to reduce pressure. Avoid holding the
Crowd cylinder extended for too long, or excessive heat
rise will occur. Replace the lock nut and re-check the
pressure to confirm reading is correct.
Main Relief Valve Parts
Service Port Relief
Valve Section 3 controls the lift function raise and
lower. The “a” port is fitted with a relief valve to protect
the lift arms from being subjected to overloading. This
cartridge valve servicing of this valve is be
replacement.
Service Port Relief Valve Adjustment
Attach a pressure gauge (0-4000 psi) to the pressure
test point at the hydraulic pump outlet.
Service Port Relief Cartridge
Use a 22mm wrench to back off the hexagon locknut
(item B) from the cartridge body (item A). The adjusting
screw (item C) requires a 6mm allen wrench for
adjustment (see above).
With the engine running at normal operating speed,
select the Lift function raise. When the cylinder is fully
extended, continue to hold the lever in the Lift raise
position. The pressure gauge should read 2300 psi. If
the pressure setting requires adjustment, turn the
wrench clockwise to increase pressure or
counterclockwise to reduce pressure. Avoid holding the
Lift cylinder extended for too long, or excessive heat
rise will occur. Tighten the lock nut and re-check the
pressure to confirm reading is correct.
7.9 TRENCHING VALVE
General Description
The Trenching Valve has been specially designed to
convert the unit to a trenching machine when the
trencher implement is attached. The valve provides
auto-sensing to ensure the trencher travel speed
remains balanced to the trencher cutting speed
regardless of the ground hardness.
The trenching valve is only fitted to machines supplied
with optional Trencher attachment.
The trencher valve assembly comprises a group of
cartridge elements forming a complex circuit segment.
Servicing and repair to the trencher valve is usually
restricted to cartridge element replacement.
Item Description
3 Poppet
5 Spring (code Green)
6 Spring Set (Top)
8 Body
9 Copper Washer (Seal)
10 Adjusting Screw
11 Cap - Lock Nut
9
10
3
5
6
8
11
PUMP PRESSURE
TEST POINT
A
B
C