HYDRAULIC SYSTEM RT880E SERVICE MANUAL
2-10 Published 11-10-2014, Control # 524-00
A temperature switch (15), located in the tube that routes
return oil to the hydraulic oil return filter in the reservoir, is
part of a circuit that controls the oil cooler fan speed; refer to
Oil Cooler, page 2-12 for more detailed information on its
operation.
A second temperature switch (14) in the hydraulic reservoir
is part of a circuit that will alert the operator to a high
hydraulic oil temperature condition. The switch is normally
closed and will open and cause the circuit to lose ground
when the hydraulic oil temperature exceeds 190°F (88°C).
When the circuit loses ground, the CAN bus system will turn
on power to illuminate the Hydraulic Oil High Temperature
Indicator in the gauge display in the operator’s cab. See
Section 3 - Operating Controls and Procedures, in the
Operator Manual for details of the Hydraulic Oil High
Temperature Indicator.
A filler neck and breather on the top of the reservoir are for
filling the reservoir and for venting it. The filler neck includes
a strainer for catching contaminants and gaskets to prevent
leaking. The breather -- which screws onto the filler neck --
allows air to enter or exhaust from the reservoir. It is most
important that the breather be kept clean to prevent damage
to the reservoir. A breather guard protects the breather and
filler neck.
Two large round access covers on the top of the reservoir
provide access for cleaning. The covers are bolted to the top
of the reservoir and have a gasket to prevent leaking. The
access holes can also be used to fill the reservoir after it has
been completely drained.
Hydraulic Oil Return Filter Assembly
The hydraulic oil return filter assembly (see Figure 2-3 and
Figure 2-4) is located in the reservoir. It bolts to the top of the
reservoir, and its bypass outlet fits into a tube welded in the
reservoir. The filter housing contains a replaceable filter
element. Returning hydraulic oil flows through the filter head,
through the filter element, and into the reservoir.
An element condition indicator on the filter head indicates
when to change the filter element. When back pressure
caused by a dirty filter element exceeds 25 psi (172.3 kPa/
1.72 bar), the filter head’s bypass feature functions to allow
the hydraulic oil to bypass the filter element and flow into the
reservoir through the bypass outlet instead. A bypass filter
screen prevents gross contamination from passing through
the filter even during bypass.
Refer to the following procedures and Figure 2-4 when
removing or installing the hydraulic oil return filter element.
Element Removal
1. Shut down all hydraulic systems.
2. Wipe any dirt from the cap on top of the return filter
head.
3. Remove the four bolts securing the cap to the return
filter head; remove cap.
4. Remove the spring and bypass valve and inspect for any
damage; replace if necessary.
5. Remove and discard the O-ring between the cap and the
return filter head.
6. Remove the element from the return filter head.
Element Installation
1. Replace the filter with one having the same part number
as the one removed.
2. Install the bypass valve and spring.
3. Install the cap on top of the return filter head making
sure that the new O-ring between the cap and filter head
is installed correctly.
4. Secure the cap to the filter head using the bolts and lock
washers; torque bolts to their specified value.
5. Activate the hydraulic system and check for leaks. Make
repairs as needed.
CAUTION
Ensure that all hydraulic systems are shut down and the
pressure is relieved. Moderate to minor injury may result
when working on a pressurized system.
Wear eye protection. Hydraulic fluid can blind or severely
damage eyes.
To Next Page
Loading...
Need help?
General
