Eaton 1 Series Owner's manual

No. 7-606
March, 1995
Eaton®
Hydrostatic Pumps
Series 1 Models 33-64
Hydrostatic Variable Pumps
Repair Information

2
Table of Contents page
Introduction ......................................................................................................................2
ID Tag ..............................................................................................................................3
Required Tools ................................................................................................................3
Exploded View Drawing and Part Names ........................................................................4
Disassembly.....................................................................................................................6
Reassembly ....................................................................................................................12
Appendix A: IPOR End Cover........................................................................................21
Appendix B: Power Limiter Valve End Cover.................................................................22
Appendix C: Control Orifice Installation and Removal...................................................23
Appendix D: Charge Pump Repair.................................................................................24
Appendix E: Special Tools.............................................................................................25
Hydraulic Fluid Requirements.........................................................................................27
Introduction
This manual provides service information for Eaton Models 33 thru 64 Variable Pumps. Step by step
instructions for the complete disassembly, inspection and reassembly of the pump are given. The following
recommendations should be followed to insure successful repairs:
• Most repairs require the removal of the pump from the vehicle.
• Cleanliness is extremely important.
• Clean the port areas thoroughly before disconnecting the hydraulic lines.
• Plug the pump ports and cover the open hydraulic lines immediately after they’re disconnected.
• Drain the oil and clean the exterior of the pump before making repairs.
• Wash all metal parts in clean solvent.
• Use compressed air to dry the parts. Do not wipe them dry with paper towels or cloth; Lint in a
hydraulic system will cause damage.
• The compressed air should be filtered and moisture free.
• Always use new seals when reassembling hydraulic pumps.
• For replacement parts and ordering information refer to parts list 6-608.
• Lubricate the new rubber seals with a petroleum jelly like Vaseline before installation.
• Torque all bolts over gasketed joints, then repeat the torquing sequence to make-up for gasket
compression.
• Verifying the accuracy of pump repairs on an authorized test stand is essential.

3
Eaton Corporation
Hydraulics Division
Spencer, Iowa 51301
Rotation
Serial No.
Model No.
Eaton
0000 00 - 000
00 00 000000
A- Displacement (cu.in./rev.)
0033 = 3.3
0039 = 3.9
0046 = 4.6
0054 = 5.4
0064 = 6.4
0076 = 7.6
B- Identifies Type of Product
21 =Variable Displacement Pump
31 =Fixed Displacement Motor
41 =Variable Displacement Motor
61 =Tandem Variable Displacement
Pumps
C- Identifies Specific Unit Configuration
D- Month of Manufacture
E- Year of Manufacture
F- Specific Serial Number of Unit
G- Identifies Direction of Input Shaft
(Pumps Only) Rotation
Observed from Shaft End of Unit
CW = Clockwise
CCW = Counterclockwise
EF
ACB
G
D
Required Tools
ID Tag
•9/64 in. Hex Key
•1/4 in. Hex Key
•1/2 in. Socket
•9/16 in. Socket
•5/8 in. Socket
•3/4 in. Socket
•7/8 in. Socket
•1 in. Socket
•1-3/8 in. Socket
•Dial Indicator with Magnetic Base
•Spring Compression Scale (0-10 lbs)
•No. 5 or 7 Retaining Ring Pliers
•Small Pair of External Retaining Ring Pliers
(45°or 90°)
•Adjustable joint Pliers
•3 in.X 1/4-20 Bolt
•Breaker Bar or Ratchet Wrench
•Torque Wrench (200 lb-ft capacity)
•18 to 20 in. Adjustable Wrench
•Shaft End Spacer (Special)
•Hammer ( steel and Plastic)
•Depth Micrometer with Extensions
•Parallel Bars
•Slide Hammer
•Split Blade Bearing Puller
•Prick Punch
•Scribe
•Punch
•Arbor Press
•Clean, Lint Free Cloths
•Loctite
•Light Petroleum Jelly
•Suitable Solvents and Cleaners
•Rotating Seal Puller (Special)
•Low Clearance Bearing Puller (Special)
•Bearing Cone Driver (Special)
•Check Valve Puller (Special)
Special Tools are shown on pages 25 and 26.

4
Gasket(s)
Charge Pump
Mounting Bolts
54
51
52
8
53
39 40
41
48
52
50
49
44
23
22
21
20
8
8
CW Propel CW Standard
Valve Plate
Gasket(s)
Control Valve/
Port Plate for
Slave Control
Mounting Bolts
19
14
16
15
13
12
37
38
4
5
6
7
11
7
10
31
7
89
7
1
23
28 29
32
70
34
35
30 42
36
43
8
45 46
47
Exploded View Drawing

5
Models 33 thru 64 Variable Pump Parts
Item
No. Description Qty. Item No. Description Qty.
1 Shaft Seal Kit 1 31 O-ring 2
2 O-ring 1 32 Trunnion Shims ♦
3 O-ring 1 34 Plug and O-ring 1
4 Mounting Flange Bolt 12 35 Pump Housing 1
5 Shipping Strap 2 36 Servo Piston S/A 2
6 Mounting Flange S/A 1 37 Retaining Ring 8
7 Bearing Cup 1 38 Pin 4
8 Dowel Pin 9 39 O-ring 2
9 Mounting Flange Gasket 1 40 O-ring 2
10 Drive Shaft S/A 1 41 Servo Sleeve 2
11 Replacement Bearing Kit ♦42 Servo Sleeve Retainer 2
12 Swashplate S/A 1 43 Cap Screw 6
13 Thrust Plate 1 44 End Cover Gasket 1
14 Rotating Group 1 45 End Cover Bearing 1
15 Piston and Slipper S/A 9 46 Shaft Shims ♦
16 Slipper Retainer Plate 1 47 End Cover 1
19 Retaining Strap and Bolts 2 48 Check Valve S/A 2
20 Cylinder Barrel 1 49 O-ring 2
21 Bearing Plate 1 50 Back-up Ring 2
22 Valve Plate 1 52 End Cover Bolt 6
23 Control Valve Option 1 53 End Cover Bolt 2
28 Trunnion Bolt 6 54 Charge Pump 1
29 Trunnion S/A 2 70 Plug and O-ring 1
30 Replacement Bearing Kit ♦
♦Parts used as required.

Hydrostatic Variable Pump Repairs
6
Disassembly
Due to the complexity of the heavy duty pump certain
subassemblies are disassembled, inspected, and
reassembled upon removal from the pump. This
procedure insures repair accuracy and helps avoid the
loss of small parts.
1Clean the exterior of the pump and drain the oil.
2Position the pump so the shaft seal is accessible.
Important: Cleanliness is extremely important; be sure
that no contaminates get into the pump.
3Using a retaining ring pliers remove the retaining ring.
Figure 1
4Screw a 3 in. X 1/4-20 bolt into the threaded hole in
the stationary seal. Pull on the bolt to remove the seal.
5Use the special pulling tool, Owatonna Tool Co. P/N
CAS 1844, to remove the rotating seal, see figure 1. If
the special tool is not available pull out the rotating seal
with a wire bent to the shape of the puller.
Note: Detailed drawings of all special tools are given in
Appendix E, in the back of this manual.
6Remove the o-ring; it will either be in the rotating seal
or on the shaft.
Note: If you are just replacing the shaft seal jump ahead
to step 105 on page 20.
7Remove the six hex head bolts that hold the control
valve to the pump.
8 Lift the control valve away from the pump and
disengage the feedback linkage, see figure 2.
9Remove the control valve gasket.
10 Inspect the control valve: Start by thoroughly
flushing the control valve with clean solvent. Then blow
it dry with compressed air. Be sure to blow through all of
the control valve’s internal passages.
Inspect the control valve linkage. Move the control lever
back and forth; it should move freely without binding.
There should be no free play in the feedback link or
control lever.
Check the control valve orifice; if it is plugged after
flushing clean or replace it. Appendix C gives
information on orifice replacement.
Figure 2
Important: The control orifice may be
installed in different locations depending
on which pump control is used. If it is
removed a new orifice must be installed
in the same location.
Control Valve
Gasket
Feedback
Linkage
Retaining Ring
Retaining
Ring Pliers
Stationary Seal
Rotating Seal
O-ring
O-ring
Bolt
Pulling Tool

7
14 Pull the two check valves from the end cover; Hook
the short end of the pulling tool in one of the check valve
cross holes, see figure 4.
If the pulling tool is unavailable remove each check valve
by inserting a screw driver into the output port and prying
up on the bottom of the check valve.
Note: A detailed drawing of the check valve pulling tool
in given in Appendix E.
15 Remove the o-rings and back-up rings from the
check valves.
Figure 4
Check Valve
Pulling Tool
Check Valve
Screw
Driver
Figure 3
11 Reposition the pump so the shaft is vertical and the
charge pump is on top. Stand the pump on two blocks
of wood as shown in figure 3.
12 Remove the four bolts that hold the charge pump to
the end cover, see figure 3. The two remaining bolts
hold the charge pump together.
Note: Information on charge pump repair is given in
Appendix D.
13 Lift the charge pump from the end cover. Remove
the gasket and two dowel pins.
Note: Keep track of the dowel pins, see figures 3, 5,
and 8. There is a total of nine dowel pins in the pump. It
is a good idea to put them in a small box so they don’t
get lost.
Dowel Pin (9)
Gasket
Bolt (4)

Hydrostatic Variable Pump Repairs
8
Figure 5
Gasket
Shims
Bearing
Cup Dowel Pin
Valve Plate
Bearing
Plate
16 Remove the end cover.
Caution: The cylinder barrel spring pre-load will
damage the pump’s internal parts if the end cover is
removed incorrectly.
Start by removing six of the eight bolts that hold the end
cover to the pump. Leave two bolts that are directly
across from each other tight.
Next, loosen the two remaining bolts one or two turns.
The end cover should rise as the bolts are loosened. If it
doesn’t tap it with a plastic hammer to break the gasket
seal.
After the gasket seal is broken loosen the bolts
gradually and evenly until the cylinder barrel spring pre-
load is relieved.
Remove the bolts and lift the end cover from the pump.
Be careful; do not drop the valve plate, it may lift away
with the end cover.
Important: Use care when handling the pump’s internal
parts. They are machined to extremely close tolerances.
17 Turn the end cover over and set it on a clean cloth.
Important: Always protect machined surfaces.
Note: The standard end cover is shown in figure 5.
Two optional end covers are available. Use the same
removal procedure for the optional end covers.
Breakdowns of the optional end covers are shown in the
appendices:
18 Remove the valve plate and dowel pin; they will
either be on the end cover or bearing plate.
Note: Pump valve plates are unidirectional and must be
matched to the input direction of the pump. The
metering slots indicate the valve plate’s direction, see
figure 6. Also be aware that there are different shaped
metering slots; ‘V’ shaped metering slots are standard,
and kidney shaped metering slots are on propel valve
plates.
19 The bearing cup is slip-fit into the end cover. The
shims under the bearing cup adjust the shaft end play.
It is not necessary to remove these parts at this time.
20 Remove the bearing plate.
21 Remove the end cover gasket.
Optional End Cover Appendix Page
IPOR A 21
Power Limiter Valve B 22

9
Input
Rotation Input Rotation
Metering
Slots
Figure 6
22 Remove the two dowel pins from cylinder barrel face,
see figure 5.
Servo Sleeve
Figure 7
23 Mark the pump housing and servo sleeves so they
can reinstalled in the same locations.
24 Remove the servo sleeve retainers.
25 Scribe position marks on each servo sleeve; Make a
horizontal line where the servo sleeve and pump
housing meet. Then make a vertical line that starts on
the servo sleeve and ends on the housing, see figure 7.
These marks will indicate how far to screw the servo
sleeves in during reassembly.
26 Remove the servo sleeves.
27 Remove two o-rings from each servo sleeve.
Servo Sleeve
Retainer
O-rings
Scribe Marks
Bolt (12)
Bearing Cup Gasket
Dowel
Pin
Figure 8
28 Reposition the pump so the control valve mount is
on top.
29 Remove the twelve hex head bolts that hold the
mounting flange to the pump.
30 Remove the mounting flange, tapping it with a plastic
hammer will help to break it loose.
31 Remove the mounting flange gasket.
Note: Do not remove the bearing cup from the mounting
flange unless it is damaged. Go to step 34 if the bearing
cup is undamaged.
32 Use an internal bearing puller or a long punch to
remove the old bearing cup. Be careful; do not damage
the mounting flange.
33 Press the new bearing cup into the mounting flange.
Be sure that it is pressed all the way to the bottom of the
recess.

Hydrostatic Variable Pump Repairs
10
Retaining
Rings
Servo
Pistons
Pin
Case Drain
Hole
Figure 9
34 Remove the inside retaining ring from each of the
pins that connect the servo piston links to the
swashplate. Slide the pins out through the case drain
holes and remove the servo pistons, see figure 9.
Note: Disassembly of the servo pistons is not required
unless they are damaged.
Figure 10
Mark Trunnion
and Housing
O-ring
Shims O-ring
Trunnion Bearing
Cone
Shims
36 Repeat the following steps to remove each trunnion:
Remove the three hex head bolts that hold the trunnion
to the pump
The trunnion fits into the pump tightly; use a slide
hammer to loosen it. Screw the slide hammer into the
threaded hole in the trunnion. The sizes of the threaded
trunnion holes are listed below:
35 Mark the pump housing and the trunnions so they
can be reinstalled in the same locations.
Model Number Screw Size
33, 39, 46 3/8-16
54, 64 7/16-14
Remove the trunnions and shims.
Important: Keep the shims with each trunnion; they
must be reinstalled on the same trunnion during
reassembly. The shims pre-load the trunnion bearings.
Remove the o-ring from the trunnion, see figure 10.
37 If the trunnion bearings are damaged replace them.
A split blade bearing puller will be needed to remove the
bearing cone from the trunnion. Use a press to install
the new bearing cone.

11
Spacer
Low Clearance
Bearing Puller
Cylinder
Barrel
Figure 11
38 Carefully remove the swashplate, cylinder barrel and
shaft through the mounting flange end of the housing.
39 Pull the end cover bearing cone from the shaft. Use a
special low clearance bearing puller and place a spacer
in the slot in the shaft.
Note: Detailed drawings of the low clearance bearing
puller and spacer are given in Appendix E. The low
clearance bearing puller was designed to protect the
cylinder barrel face, see cut-away in figure 11. The
spacer will prevent the slotted end of the shaft from
spreading.
Critical Sealing
Area
40 Remove the shaft and bearing assembly from the
swashplate and cylinder barrel. Keep the cylinder barrel
and pistons together.
Note: Do not remove the bearing cone from the shaft
unless it is damaged. Go to step 43 if the bearing cone
is undamaged.
41 Press the old bearing cone from the shaft.
Caution: Do not damage the sealing area of the shaft,
see figure 12. The shaft sealing area is between the
bearing journal and the keyway or splined end of the
shaft. This area is extremely critical.
42 Press the new bearing cone onto the shaft. Use the
special stop limit tool shown in Appendix E of this
manual. The position of the bearing cone on the shaft is
important.
Figure 12

Hydrostatic Variable Pump Repairs
12
A - B = C
Spacer
Retaining
Strap
Trunnion
Bearing Cup
Cylinder Barrel
Swashplate
Figure 13
43 Set the swashplate and cylinder barrel assembly on
one of the trunnions; in this position it will be easier to
break the retaining strap bolts loose. Remove one of the
retaining straps and loosen the other.
Important: keep the cylinder barrel and pistons
together.
44 Reposition the swashplate and cylinder barrel
assembly so the cylinder barrel is on the bottom.
Remove the swashplate by lifting it slightly and sliding it
over to disengage the retaining strap.
45 Remove the retaining strap and thrust plate from the
swashplate.
46 Replace the trunnion bearing cups if they are
damaged. Use a long punch to remove the old bearing
cups, then carefully press the new bearing cups into the
swashplate.
Reassembly
Inspect the cylinder barrel, pistons, piston slippers, and
thrust plate. Replace any worn or damaged parts.
Check all mating surfaces; replace any parts with
scratches or burrs that could cause leakage. Inspect
parts for excessive wear and replace as necessary.
Wash all metal parts in clean solvent and blow them dry
with compressed air. Do not wipe parts dry with paper
towels or cloth. Lint in a hydraulic system will cause
damage.
Always use new seals when reassembling hydraulic
pumps. Refer to parts list 6-608 for seal part numbers,
replacement parts, and ordering information.
Important: During reassembly lubricate the new rubber
seals with a petroleum jelly like Vaseline. Also lubricate
all machined surfaces and bearings with clean hydraulic
fluid.
47 Before beginning reassembly check the piston
slipper clearance:
First, use a vernier calipers to measure the spacer
height, height “A” in figure 14.
Next, measure the thickness of the slipper retainer plate
and piston slippers, Thickness “B” in the figure.
Finally, calculate the piston slipper clearance “C” by
subtracting thickness “B” from height “A”.
Clearance “C” must not exceed .008 in. [,20 mm].
Figure 14
Retaining
Strap
Spacer
Piston
Slipper Retainer
Plate
Thrust Plate Piston Slipper
Swashplate

13
Swashplate
Thrust Plate
Slipper Retainer
Plate
Loctite Four
Threaded Holes
Bearing Cup
Retaining
Strap
Figure 15
48 Position the cylinder barrel, pistons, and slipper
retainer so the piston slippers are on top.
49 Apply two drops of Loctite 271 in each of the four
retaining strap holes in the swashplate. Apply the
Loctite no closer than two threads from the running
surface. Do not apply Loctitie to the retaining strap
bolts.
Caution: Remove all excess Loctite, it will contaminate
the pump if not removed.
50 Place the thrust plate in the swashplate.
51 Install one of the retaining straps, and leave the bolts
loose.
52 Apply a light coating of clean hydraulic fluid to the
thrust plate.
53 Fit the swashplate onto the cylinder barrel assembly.
Be sure the slipper retainer plate is between the
swashplate and retaining strap.
54 Turn the swashplate and cylinder barrel over so the
swashplate is on the bottom.
55 Install the second retaining strap and tighten all four
retaining strap bolts to 18 lb-ft [25 Nm]. Remove all
excess Loctite.
56 Liberally lubricate the pistons slippers, thrust plate,
retainer plate, pistons, and cylinders. These parts must
have sufficient start-up lubrication.
57 Slide the shaft and bearing assembly through the
swashplate into the cylinder barrel.
Trunnion
Shims
O-ring
Control Valve
Mount
Shims O-ring
Figure 16
58 Carefully, put the swashplate, cylinder barrel, and
shaft into the pump housing. Be sure the feedback
linkage is by the control valve mount.
59 Lubricate and install a new o-ring on each trunnion.
60 Install the trunnions and shims in their original
locations.
61 Install the trunnion bolts and tighten them to the
specified torque given below:
Model Number Trunnion Bolt Torque
33, 39, 46 28 lb-ft [38 Nm]
54, 64 44 lb-ft [60 Nm]

Hydrostatic Variable Pump Repairs
14
62 After the bolts are torqued
strike one of the trunnions to
free up the swashplate’s
movement.
63 Measure the swashplate
breakaway force with a spring
compression scale. Attach the
scale to the feedback linkage as
shown in figure 17. A
swashplate breakaway force of
2 to 5 lb [,9 to 2,3 Kg] is
required. Add or subtract
trunnion shims as needed.
Important: The trunnion shims
on each side of the pump
should be equal thickness. The
maximum allowable difference
between the sides is .010 in. [,3
mm].
Spring
Compression
Scale
Strike the Trunnion to
Free-up Swashplate
Movement
66 Lubricate and install new o-rings on the servo
sleeves.
67 Install each servo sleeve in its original location. Start
by lifting one of the servo pistons, tilting the swashplate
to its maximum angle, then carefully fit the servo sleeve
over the piston. Next, lower the servo sleeve and piston
into the pump housing until the threads meet. Finally,
screw the servo sleeve in until the scribe marks line up.
Repeat this procedure for the second servo sleeve.
64 Install the servo pistons. Line up the servo piston
links and install the pins through the case drain holes as
shown in figure 18.
65 Carefully remove the shaft and bearing assembly.
Reposition the pump so it is sitting on the mounting
flange gasket surface.
Note: Do not let the cylinder barrel slide off of the
pistons.
Figure 18 Figure 19
Case Drain
Hole
Retaining
Rings Pin
Servo
Pistons
Servo
Sleeves
O-rings
Figure 17

15
Figure 20
68 Check the zero angle of the swashplate.
Important: Zeroing the swashplate insures that the
springs on the servo pistons will return the swashplate to
neutral when the control lever is centered.
69 Place parallel bars across the end cover gasket
surface and measure the depth to the swashplate on
each side of the cylinder barrel, as shown in figure 20.
The maximum allowable difference in the
measurements is .0005 inch [,012 mm].
The springs on the servo pistons must hold the
swashplate tight; The maximum allowable
swashplate rock is .001 inch [,03 mm].
Screw the servo sleeves in or out to adjust the zero
angle of the swashplate.
70 Install the servo sleeve retainers and re-stake if
necessary.
Parallel
Bars
Depth
Micrometer
Cross-
Section
Swashplate
Shipping
Strap
Dowel
Pin
Mounting
Flange
Bearing
Gasket
Figure 21
71 Reposition the pump so the control valve mount is on
top. Be careful do not let the cylinder barrel slide out off
the pump.
72 Carefully slide the shaft and bearing assembly into
the pump.
73 Install two dowel pins in the holes in the mounting
flange surface of the pump housing.
74 Place a new mounting flange gasket on the pump
housing. Hold it in place with petroleum jelly.
75 Lubricate the mounting flange bearing with clean
hydraulic fluid
76 Install the mounting flange on the pump.
77 Install the twelve mounting flange bolts. Remember
to install the shipping strap. Tighten the bolts to the
torque specified in the table below:
Model Number Mounting Flange
Bolt Torque
33, 39, 46 28 lb-ft [38 Nm]
54, 64 44 lb-ft [60 Nm]

Hydrostatic Variable Pump Repairs
16
Bearing Cone Driver
Shaft
Support
Bearing
Cup
Shims
Temporarily
Assemble Without
Valve or Bearing
Plates to Check
Shaft End Play
Figure 23
81 Install two dowel pins in the holes in the end cover
surface of the pump housing.
82 Install a new end cover gasket.
83 Check the pump shaft end play before installing the
bearing and valve plates.
Be sure the bearing cup and shims are in the end cover
and place it on the pump.
Install the eight end cover bolts and tighten them
alternately to the torque specified in the table below:
Turn the pump over so the mounting flange and shaft
are on top. Place a block of wood under the end cover
so the weight of the pump is not on the servo sleeves.
Figure 22
78 Turn the pump over so the shaft is vertical and the
mounting flange is down.
79 Support the pump’s shaft and use a bearing driver to
install the end cover bearing cone, see figure 22. Be
sure the bearing cone is seated against the shoulder of
the shaft.
Note: A detailed drawing of the bearing cone driver is
shown in Appendix E of this manual.
80 Remove the shaft support.
Model Number End Cover Bolt
Torque
33, 39, 46 39 lb-ft [53 Nm]
54, 64 63 lb-ft [85 Nm]

17
Magnetic Base
Dial Gauge
Pliers
Figure 24 Figure 25
Dowel Pins
Valve
Plate
Bearing
Plate
Gently tap the shaft into the pump with a plastic hammer
to seat the bearings.
Place a dial gauge, with a magnetic base over the shaft
as shown in figure 24. Grasp the shaft low with a pliers
and pry it up to get the end play reading.
The pump shaft end play must be from .002 in. to
.007 in. [,05 mm to ,17 mm].
Adjust the end play by adding or subtracting shims from
under the end cover bearing cup.
84 Turn the pump over and remove the end cover.
85 Install two dowel pins in the holes in the cylinder
barrel face.
86 Place the bearing plate on the cylinder barrel and
engage it with the dowel pins.
87 Liberally lubricate the bronze surface of the bearing
plate with clean hydraulic fluid.
88 Install a dowel pin in the hole in the end cover.
89 Place the valve plate on the end cover. Be sure it
engages with the dowel pin.

Hydrostatic Variable Pump Repairs
18
End Cover
Figure 26
90 Holding the valve plate in place carefully install the
end cover.
Note: Use petroleum jelly to help hold the valve plate to
the end cover.
91 Install the eight end cover bolts, remember the
shipping strap.
92 Tighten the end cover bolts evenly so the cylinder
barrel spring pre-load is taken-up gradually. Torque
them alternately to the specifications given in the table
below:
93 Lubricate and install new o-rings and back-up rings
on the check valves. The back-up ring must be installed
on the charge pump side of the o-ring, see figure 27.
94 Install the check valves in the pump end cover.
Push them down until their tops are flush with the
surface of the end cover.
Figure 27
End Cover
Back-up
Ring
O-ring
Check
Valves
Model Number End Cover Bolt
Torque
33, 39, 46 39 lb-ft [53 Nm]
54, 64 63 lb-ft [85 Nm]

19
95 Install the two remaining dowel pins in the holes in
the end cover, see figure 28.
96 Place a new charge pump gasket on the end cover.
97 Rotate the charge pump shaft so the tang and the
dowel pin holes line-up correctly with the pump. Then
carefully install the charge pump.
Note: Some charge pumps have splined drives.
98 Install the four hex head bolts that hold the charge
pump to the pump end cover. Torque them alternately
to 25 lb-ft [34Nm]. Charge pumps that have ‘A’ or ‘B’
pads require a torque of 22 lb-ft [30 Nm].
Figure 28
Bolt (4)
Charge
Pump
Dowel Pin
Gasket
Control Valve
Gasket
Feedback
Linkage
Figure 29
99 Reposition the pump so the control valve mount is on
top.
100 Place a new control valve gasket on the pump.
101 Connect the feedback linkage and position the
control valve on the pump.
Important: When the control valve is positioned on the
pump make sure the feedback linkage points towards
the end cover.
102 Install the six hex head bolts and tighten them
finger tight.
103 Move the control lever back and forth; it should
move freely in both directions and self-center. If it
doesn’t recheck the feedback linkage.
104 Tighten the six hex head bolts to 16 lb-ft [22 Nm].

Hydrostatic Variable Pump Repairs
20
Retaining
Ring Stationary
Seal Rotating
Seal
Pulling
Tool O-ring
Figure 30
105 Reposition the pump so the shaft seal can be
installed.
Note: Eaton recommends replacing the entire shaft
seal. Use Shaft Seal Kit P/N 990231.
Important: The metal-to-metal sealing surfaces are
critical. Clean the areas of contact with a suitable
solvent then blow them dry. The solvent must evaporate
without leaving a residue. Do not touch the sealing
surfaces after cleaning.
106 Apply petroleum jelly to the o-ring and install it in
the rotating seal
107 Apply a light coating of clean hydraulic oil to the
cleaned metal sealing surface of the rotating seal.
108 Install the rotating seal using the special pulling tool
(CAS 1844).
109 Screw a 3 in. X 1/4-20 bolt into the threaded hole in
the new stationary seal. The bolt provides a convenient
means for holding the seal.
110 Apply petroleum jelly to the o-ring that is around
the largest part of the stationary seal.
111 Apply a light coating of clean hydraulic oil to the
cleaned metal sealing surface of the stationary seal.
112 Install the stationary seal.
113 Using the retaining ring pliers install the retaining
ring with the beveled side out, be sure that it is seated
properly.
Caution: Verifying the accuracy of repairs on an
authorized test stand is essential.