MTD 243-635-000 - Manual (Page 14)

HOW YOUR LOG SPLITTER OPERATES
THE PUMP
A two-stage log splitter pump has one large aid one
small gear section, using common inlet anc outlet
ports. Below a preset pressure (called unloadin g pres­
sure) a check valve between the two gear s jctions
allows both flows to combine. Together, the tw o gear
sections create a large volume flow which pnduces
rapid cylinder movement under low load conditi ms.
Above unloading pressure, a pilot pressu e line
(which simulates actual pressure at the cylindr r) acti­
vates the unloading valve, which causes the flow to
bypass the large gear section and return to tho pump
inlet area. The small gear section is now opsrating
alone, and will generate the higher pressure neces­
sary for the actual log splitting operation.
The original factory setting for the unloading \ aive is
designed to provide maximum flow while remaining
below engine stalling load. Note: Splitting ca|:iabiiity
is not affected by the setting of the unit lading
vaive. Do not attempt to adjust or reset it vrithout
a pressure gauge (should be performed by an
authorized service deaier only).
THE DIRECTIONAL VALVE AND CYLINDER
From the pump, oil flows to a four way, three position
directional valve. At the neutral position thi:; valve
directs the flow back to the oil reservoir, bypassing
the cylinder. When the directional valve is directing
the flow to the back of the cylinder, the cylinder rod
extends quickly until it meets significant resi; stance.
Upon reaching unloading pressure, movemen of the
shaft will slow but will continue forward. If the pres­
sure reaches a preset maximum (called relief valve
pressure) the relief valve, located within the direction­
al valve, will allow the flow to bypass the cylinder and
return to the reservoir. This can happen when the
cylinder rod meets excessive resistance, or when it
reaches the end of its stroke and can move no farther.
NOTE: Never operate at relief valve pressure for
more than a few seconds.
When the directional valve is directing the flow to the
front of the cylinder, the rod will retract quickly since it
is encountering no resistance. The relief valve will
momentarily bypass the flow at the end of the return
stroke but the directional valve should then automati­
cally return to the neutral position, directing the flow
directly into the reservoir. This serves to protect the
pump from possible damage due to prolonged opera­
tion at relief valve pressure.
Because of the potential for system damage, the relief
valve is carefully and precisely preset by the manu­
facturer.
NOTE: The user should not attempt to adjust or
change the setting of the relief valve.
OPERATIDNAL PRDBLEMS
If you have trouble with your log splitter, please refer
to the Hydraulic Trouble Shooting Guide.
NOTE: Readjustment of valves or disassembly of
pump should be performed by an authorized ser­
vice dealer only.
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