Hydrostatic Testing Procedures; Hydraulic Testing - Toro TX525 Service Manual

Hydraulic Testing

Hydraulic testing needs to be done in a systematic
manner with a basic understanding of the hydraulic
system and functions. It is recommended that you have
the hydraulic schematic for the model and serial number
being tested. Schematics can be obtained from this
service manual or from the Toro Operator Manual or
Parts Catalog provided with the unit.
The TX525 hydraulic system utilizes a dual gear pump
to push oil to all the hydraulic components of the unit.
The TX525 hydraulic systems can be separated into
three circuits: loader, auxiliary and drive. These hydraulic
systems are open circuit systems that allow oil to flow
when the valves and hydrostatic pumps are in neutral
position.
The dual gear pump draws the oil from the hydraulic
tank and pushes the oil through the hydraulic lines,
hoses and valves. The pump creates the flow [gallons
per minute (gpm)]. The auxiliary and loader circuits are
separate circuits which operate at their own pressure
and flow. Return line oil from the loader circuit is used to
supply oil to the two drive system hydrostatic pumps.
The recommended flow (gpm) and pressure (psi)
values for each of the different circuits are located in
the specification section of this manual. Refer to those
values to properly troubleshoot each circuit. The tests
in the following section need to be done at various
locations to determine which component(s) may not be
functioning correctly.
Loader Circut
Oil is drawn from the hydraulic tank by the front section
of the dual gear pump (farthest from engine) and flows
into the loader valve. The loader valve relief restricts the
hydraulic oil which creates system pressure (psi). When
the loader valve is moved forward or back from neutral
position it directs the hydraulic oil to the lift cylinder.
When the loader valve is moved left and right it directs
hydraulic oil to the tilt cylinder.
TX525 Service Manual
HYDRAULIC TESTING
Auxiliary Circuit
Oil is drawn from the hydraulic tank by the rear section
of the dual gear pump (closest to the engine) and
flows into the auxiliary valve. The auxiliary valve relief
restricts the hydraulic oil which creates system pressure
(psi). The auxiliary valve directs the hydraulic oil to the
couplers. When the auxiliary lever is moved toward the
drive handle the female coupler is pressurized, which
runs the attachment in forward drive. When the auxiliary
lever is moved away from drive handle the male coupler
is pressurized and the attachment runs in reverse drive.
Drive Circuit
The drive system uses two hydrostatic pumps and two
wheel motors. The hydrostatic pumps are supplied with
low pressure oil returned from the loader valve. This
oil is filtered and then fed to the hydrostat pumps. (A 5
psi (0.34 bar) check valve on the return hose between
the filter and tank is used to ensure a constant supply
of oil to the hydrostatic pumps). When the drive handle
is moved out of the neutral position, hydraulic oil is
pumped to the wheel motors that drive the tracks.

Hydrostatic Testing Procedures

Certain procedures require the vehicle engine to be
operated and the vehicle to be raised off the ground.
To prevent possible injury to the servicing technician
and/or bystanders, ensure the vehicle is properly
secured.
Do not attempt any adjustments with the engine
running. Use extreme caution while working in or
around all vehicle linkage! Follow all safety procedures
outlined in the Operators Manual.
The purpose of the flow test is to isolate and determine
if there is a problem with either the hydrostatic pump or
the wheel motor.
Ensure all fittings and hoses are attached securely.
This test is being completed on the vehicle's high
pressure lines. Failure to perform this test properly
could result in bodily injury.
Rev. 000
WARNING:
WARNING:
CAUTION:
9-3