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Repair Information
– Series 2 Variable Displacement Pump
The following procedures describe complete disassembly of the
Series 2 variable displacement pump. As the variable displace-
ment pump is available in two frame sizes with many displace-
ments and options, these procedures cover the basic units only.
The procedures for the
units with options that are
not shown are basically the
same. The level of cleanli-
ness maintained when re-
pairing the pump could af-
fect pump performance.
Work in a clean area. After
washing the parts with
clean solvent, blow the parts dry with air. Inspect all mating
surfaces. Replace all damaged parts. Do not use grit paper, files
or grinders on finished parts.
NOTE: Whenever a pump is disassembled, it is a good policy to
replace all seals. Lubricate new seals with petroleum jelly be-
fore installation. Use only clean, recommended hydraulic fluid
on finished surfaces before reassembly.
It is recommended that the exterior of the pump be thoroughly
cleaned before disassembly. Make sure all open ports are sealed.
To remove the input shaft
seals retaining ring, use a
pair of internal retaining
ring pliers with .090
straight tips and carefully
remove the retaining ring
and spacer ring(s) from
the pump housing. It will
be easier to remove the
actual shaft seal later on during the disassembly of the pump .
(see Figure 2).
To remove the control valve assembly, use 1/4 in. bit socket or
hex key and remove the
control valve assembly’s
five retaining cap screws.
With the retaining cap
screws removed, remove
the control valve assembly
by simply lifting it straight
up. (see Figure 3)
Next remove the control valve
assembly gasket and discard.
(see Figure 4)
Remove the control valve feed-
back assembly by simply lifting
it straight up. (see Figure 5)
Depending upon the type of
control used, and application
used on, determines orifice size
and location. The orifices are
staked in three places to retain
them in their pockets. The ori-
fices sizes are stamped on the
face of each orifice. These ori-
fices need not be removed un-
less orifice size need to be changed. (see Figure 6)
The orifice on earlier manufac-
tured pump (P) were either
staked in the control housing
shown here or a loose fit in the
control housing. (see Figure 7)
Using a 9/16 hex key or allen
wrench, remove the socket
head plug. This plug is used to
retain the clocking link which we
will remove later. (see Figure 8)
The following repair information may be used in the inspection,
conversion and repair of the Eaton Series 2 Variable Displace-
ment Pump. The Pump Shown in this section incorporates the
manual displacement control, high pressure relief valves, inter-
nal pressure override valves and the high trorque auxiliary pump
option.
Complete Disassembly
Figure 5
Figure 6
Figure 4
Figure 1
Figure 2
Figure 3
Figure 7
Figure 8