Snapper 1650 Series User Manual

SECTION 5 ■ HYDRAULIC LIFT SYSTEM
The hydraulic lift system on tractors with
hydrostatic drives includes the hydraulic control
valve located under the right rear fender, the mid¬
mount implement lift cylinder on the right side of the
frame approximately under the instrucment panel
and the rear PTO attachment lift cylinder on the left
rear side of the frame. Hydraulic pressure is for the
lift system is supplied by the transmission charge
pump indicated by the arrow in figure 5.1.
Normal operating pressure for the hydraulic lift
system should be in the 700 to 800 psi range. If too
low, the cylinders will not lift properly. If too high,
seal leakage will eventually occur. A 0-1000 psi
pressure gauge and a Tee fitting of appropriate size
are needed for checking pressure in the hydraulic lift
system. To check the pressure, proceed as follows.
1. Remove center console cover.
2. With engine off, disconnect hose fitting from
charge pump (see figure 1) and install Tee fitting
then reconnect hose to Tee fitting.
FIG. 5.1-CHARGE PUMP HOSE FITTING.
3. Connect the pressure gauge to the Tee fitting.
4. Start tractor engine and activate lift lever until
relief valve "pops" then hold lever and observe
pressure on gauge.
5. If the pressure is considerably higher than 800 psi
or lower than 700 psi, readjust as described in step
6 .
6. P ressure adjustment is made on the adjuster of
the control valve as shown in figure 5.2. Loosen the
jam-nut and turn setscrew in clockwise direction to
increase pressure or in opposite direction to
decrease the pressure. When pressure is in the cor¬
rect range, hold setscrew and tighten the jam-nut to
lock in the new setting. Stop engine and remove Tee
fitting and reconnect hose to charge pump.
NOTE: If the pressure can not be corrected by read¬
justing, remove and recondition the control valve as
described in the follow.
FIG. 5.2-CONTROL VALVE PRESSURE ADJUSTER.
CONTROL VALVE
Complete access to the control valve is gained by
removing the rear fender- seat assembly. To remove
the control valve for reconditioning, disconnect the
hydraulic lines as shown in figure 5.3 and remove
the three bolts securing the valve body to the moun¬
ting bracket. Reverse this procedure when reinstall¬
ing the reconditioned control valve.
RECONDITIONING CONTROL VALVE
Three tie bolts hold the valve bodies together. If a
spool or body is damaged, replace the complete
valve body. Always use new O-rings and shims.
These are supplied in kit form which is listed along
with other repair kits in the hydraulic section of the
tractor parts manuals. Separate the valve bodies as
follows:
1. Stand the control valve on the heads of the three
tie-bolts and remove the nuts and washers from the
tie-bolts. The plates and bodies are indentified in
figures 5.5. and 5.6.
FIG. 5.3 -CONTROL VALVE LINE CONNECTIONS.
1. Pump Inlet. 2. Rear lift cylinder. 3. Mid lift cylinder.
4. Mid lift cylinder. 5. Rear lift cylinder. 6. Outlet line.
5.1

Snapper 1650 Series Specifications

General

Brand	Snapper
Model	1650 Series
Category	Lawn Mower
Language	English