2-6 Published 08-25-09, Control # 077-04
HYDRAULIC SYSTEM RT9130E SERVICE MANUAL
4. Hydraulic hose assemblies operating in climate zones
“A” and “B” (Table 2-1) with high ambient temperatures,
could see hose service life reduced by 40 to 50%,
therefore, it is recommended to replace these hoses
after 4000 to 5000 hours of service life.
5. Hydraulic hose assemblies operating in climate zones
“D” and “E” (Table 2-1) cold climates should expect a
degrade of mechanical properties such as elasticity,
therefore, it is recommended these hoses be inspected
and addressed accordingly.
Table 2-1
SUPPLY PRESSURE AND RETURN CIRCUIT
Description
The supply pressure and return circuit is made up of several
circuits which route hydraulic oil from the four hydraulic
pumps to the directional control valves for the individual
operating circuits. The supply pressure and return circuit
consists of the reservoir and integral filter, four hydraulic
pumps, a hydraulic oil cooler, and a 11-port hydraulic swivel.
Refer to Hydraulic Pumps in this section for descriptions and
maintenance instructions for each hydraulic pump. Refer to
Section 6 - Swing System for description and maintenance
instructions for the 11-port hydraulic swivel.
The supply pressure and return circuit uses Ports 2 and 3 for
pump supply and the dual Port 1 for return. Each operating
circuit’s description and components begin with the circuit’s
directional control valve.
Hydraulic Reservoir and Filter
The reservoir (Figure 2-3), attached to the right side of the
carrier frame, has a total capacity of 1363 liters (360 gallons)
total, or 1226 liters (324 gallons) to the full mark. The all-steel
reservoir has an internally mounted full-flow filter and integral
baffles that help cool the hydraulic oil and prevent hydraulic
oil foaming.
Hydraulic oil flows through four tubes at the lower rear of the
reservoir to the four hydraulic pumps. Almost all of the return
flow goes through the filter at the top of the reservoir. The
return line that goes directly into the reservoir (instead of
through the filter) is from the No. 4 port (drain) of the 11-port
swivel.
A magnetized drain plug in the bottom of the reservoir
collects metal particles from the hydraulic oil if it becomes
contaminated.
A sight gauge is located on the right side of the reservoir to
indicate hydraulic oil level.
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.
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.
The hydraulic oil filter is located in the reservoir. It bolts to the
top of the reservoir. The filter contains a replaceable filter
element. Returning hydraulic oil flows through the filter’s filter
element into the reservoir. Bypass fluid internal to the filter
flows to the reservoir also.
Zone Classification
A Tropical Moist: All months average above 18° C. Latitude 15° - 25° North and South
B Dry or Arid: Deficient precipitation most of the year. Latitude: 20° - 35° North and South
C Moist Mid-Latitude: Temperature with mild winters. Latitude: 30° - 50° North & South
D Moist Mid-Latitude: Cold winters. Latitude 50° - 70° North & South
E Polar: Extremely cold winters and summers. Latitude: 60° - 75° North & South