Parker HP2 Series Manual

HP2 Series
Hydrostatic Tandem
Pump Service Procedure
HY13-1521-M1/US
Parker Hydrostatic
Tandem Pumps
Effective: March, 2009

Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Contents
WARNING
FAILURE OR IMPROPER SELECTION OR IMPROPER USE OF THE PRODUCTS AND/OR SYSTEMS DESCRIBED HEREIN OR RELATED
ITEMS CAN CAUSE DEATH, PERSONAL INJURY AND PROPERTY DAMAGE.
This document and other information from Parker Hannin Corporation, its subsidiaries and authorized distributors provide product and/or
system options for further investigation by users having technical expertise. It is important that you analyze all aspects of your application
and review the information concerning the product or system in the current product catalog. Due to the variety of operating conditions and
applications for these products or systems, the user, through his/her own analysis and testing, is solely responsible for making the nal
selection of the products and systems and assuring that all performance, safety and warning requirements of the application are met.
The products described herein, including without limitation, product features, specications, designs, availability and pricing, are subject
to change by Parker Hannin Corporation and its subsidiaries at any time without notice.
© Copyright 2008, Parker Hannin Corporation, All Rights Reserved
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Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Contents
Section 1 General Information
Denitions/Disclaimer ..........................................................................................4
Introduction/Design Features...............................................................................5
Troubleshooting Guide.........................................................................................6
Troubleshooting Checklist....................................................................................7
Tools & Materials Required for Servicing .............................................................8
Exploded Views.............................................................................................. 9-12
Section 2 Reseal & Repair
Disassembly................................................................................................. 13-32
Assembly...................................................................................................... 33-51
Section 3 Maintenance
System Maintenance Tips..................................................................................52
Hydraulic Fluids .................................................................................................53
Filtration .............................................................................................................53
Oil Temperature..................................................................................................53
3
3
General Information
Definitions/Disclaimer............................................................................................................................ 4
Introduction/Design Features ................................................................................................................ 5
Troubleshooting Guide .......................................................................................................................... 6
Troubleshooting Checklist ..................................................................................................................... 7
Tools & Materials Required for Servicing............................................................................................... 8
Exploded Views...............................................................................................................................10-11
Reseal & Repair
Disassembly...................................................................................................................................12-31
Assembly........................................................................................................................................32-50
Maintenance
System Maintenance Tips ................................................................................................................... 51
Hydraulic Fluids................................................................................................................................... 52
Filtration............................................................................................................................................... 52

Service Manual
HP2 Series Hydrostatic Tandem Pumps
4
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
HY13-1521-M1/US
General Information
WARNING A warning describes hazards or unsafe practices
which could result in severe personal injury or death.
CAUTION A caution describes hazards or unsafe practices which could
result in personal injury, product or property damage.
NOTE A note gives key information to make following a procedure
easier or quicker.
Disclaimer
This Service Manual has been prepared by Parker Hannin Corporation for reference and use by mechanics who
have been trained to repair and service hydraulic pumps on commercial and non-commercial equipment appli-
cations. Parker Hannin Corporation has exercised reasonable care and diligence to present accurate, clear and
complete information and instructions regarding the techniques and tools required for maintaining, repairing and
servicing the Parker HP2 Series Hydrostatic Tandem Pump. Since this is a general Service Manual, the photo-
graphs and illustrations may not look exactly like the pump being serviced. The procedures, therefore, must be
carefully read and understood before servicing.
If inspection or testing reveals evidence of abnormal wear or damage to the HP2 Tandem Pump or if you en-
counter circumstances not covered in the Manual, STOP - CONSULT THE EQUIPMENT MANUFACTURER’S
SERVICE MANUAL AND WARRANTY. DO NOT TRY TO REPAIR OR SERVICE A HP2 TANDEM PUMP WHICH
HAS BEEN DAMAGED OR INCLUDES ANY PART THAT SHOWS EXCESSIVE WEAR UNLESS THE DAMAGED
AND WORN PARTS ARE REPLACED WITH ORIGINAL PARKER REPLACEMENT AND SERVICE PARTS AND
THE UNIT IS RESTORED TO PARKER SPECIFICATIONS FOR THE HP2 TANDEM PUMP.
It is the responsibility of the mechanic performing the maintenance, repairs or service on a particular HP2 Tan-
dem Pump to (a) inspect the unit for abnormal wear and damage, (b) choose a repair procedure which will not
endanger his/her safety, the safety of others, the equipment or the safe operation of the HP2 Tandem Pump, and
(c) fully inspect and test the HP2 Tandem Pump and the hydraulic system to ensure that the repair or service of
the HP2 Tandem Pump has been properly performed and that the HP2 Tandem Pump and hydraulic system will
function properly.
Conversions INCHES mm INCHES mm
.020 .511 1.060 26.92
.021 .531 1.295 32.89
.029 .741 1.297 32.94
.030 .760 1.396 35.46
.111 2.81 1.398 35.51
.119 3.02 1.620 41.15
.152 3.86 1.622 41.20
.160 4.06 1.983 50.37
.296 7.52 1.985 50.42
.304 7.72 2.120 53.85
.460 11.68 2.122 53.90
.470 11.94 2.233 56.72
.500 12.70 2.235 56.77
.585 14.86 2.483 63.07
.595 15.11 2.485 63.12
.660 16.76 2.500 63.5
.675 17.15 2.88 73.2
1.058 26.87
Definitions
4

Service Manual
HP2 Series Hydrostatic Tandem Pumps
5
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
HY13-1521-M1/US
General Information
Introduction
The three-column format used in this Service Manual will help make it easy for you to service a hydraulic pump.
Column 1 illustrates the procedure with photographs, Column 2 gives a brief key for each step, and Column 3
explains in detail the procedure you should follow. Pay special attention to the notes, cautions and warnings.
This manual contains troubleshooting information and checklists. With them you can diagnose a hydraulic
system problem without removing the HP2 Tandem Pump. The checklists will help you to determine where the
problem may be.
Item numbers on the exploded view correspond with item numbers used throughout the Service Manual.
As you gain experience in servicing the HP2 Tandem Pump, you may nd that some information in this Service
Manual could be clearer and more complete. If so, let us know about it. Don’t try to second-guess the Service
Manual; if problems occur that you cannot solve, please contact our service department at 423-639-8151, or
your local Parker approved distributor. Servicing the HP2 Tandem Pump should be safe and productive. Visit our
web site at www.parker.com/pumpmotor.
HP2 SERIES VARIABLE DISPLACEMENT, CLOSED LOOP DUAL PISTON PUMP
Large area cooling ns result in a cooler running system•
Center block and housings are sturdy, lightweight aluminum, excellent at dispersing•
heat, resulting in an overall cooler system
Replaceable bi-metal port plate increases contamination resistance and efciency of•
pump as well as serviceability
Forged trunnion shaft increases shaft strength and lengthens pump life•
Nylon caged thrust bearings improve lubrication and vibration absorption, thus•
lengthening life of pump
Compact size for similar systems for increased exibility in machine design•
Larger radial shaft bearings (20mm) provide additional side load capacity and less•
machine downtime
18% larger shaft than competitive pumps for reduced shaft breakage•
Smaller diameter pistons reduce load on thrust bearings compared to competitive•
pumps
Reduced maximum swash plate angle lowers piston-to-bore velocity and enables•
pistons to be more centered on the thrust bearing when swash plate is inclined
resulting in increased pump and bearing life
Two independently controlled, variable displacement, over-center piston pumps•
Single input drive shaft•
2.5 quart integral reservoir•
Integral lter and system cooling fan•
5

Service Manual
HP2 Series Hydrostatic Tandem Pumps
6
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
HY13-1521-M1/US
General Information
Hydraulic Components
If you think the problem is caused by a hydraulic com-
ponent, start by checking the easy-to-reach items.
Check all hoses and lines for cracks, hardening or
other signs of wear. Reroute any usable hoses that are
kinked, severely bent, or that rest against hot parts.
Look for leaks, especially at couplings and ttings.
Replace any hoses or lines that don’t meet system
ow and pressure ratings.
Next, go to the reservoir and lters. Check uid level
and look for air bubbles. Check the lter(s). A lter
with a maximum of 20 micron ltration is included for
the HP2 Tandem pump system.
Visually check other components to see if they are
loosely mounted, show signs of leaks, or other dam-
age or wear.
Excessive heat in a hydraulic system can create
problems that can easily be overlooked. Every system
has its limitation for the maximum amount of tempera-
ture. After the maximum temperature is attained and
passed, the following can occur:
• oil seal leaks
• pump loss of efciency (resulting in lower
transmission speeds)
• pump failure
• hoses become hard and brittle
• hose failure
A normal temperature range means an efcient
hydraulic system. Consult the manuals published by
equipment and/or component manufacturers for maxi-
mum allowable temperatures and hydraulic tests that
may be necessary to run on the performance of the
hydraulic components. The HP2 Tandem pump is not
recommended for hydraulic systems with maximum
temperatures above 230° F (110° C).
Troubleshooting Guide
NOTE Before troubleshooting any system problem,
check service literature published by the
equipment and/or component manufacturers.
Follow their instructions, if given, for checking
any component other than the HP2 Tandem
pump.
Preparation
Make your troubleshooting easier by preparing as
follows:
• work in a clean, well-lighted place
• have proper tools and materials nearby
• have an air pressure source.
WARNING Since solvents are ammable, be ex-
tremely careful when using any solvent.
Even a small explosion could cause injury
or death.
WARNING Wear eye protection and be sure to com-
ply with OSHA and other maximum air
pressure requirements.
Preliminary Checks
Hydraulic systems are often trouble-free. Hence, the
problem an operator complains of could be caused
by something other than the hydraulic components.
Thus, once you have determined that a problem ex-
ists, start with the easy-to-check items, such as:
• Parts damaged from impact that were not
properly repaired, or that should have been
replaced
• Improper replacement parts used in previ-
ous servicing
• Mechanical linkage problems such as bind-
ing, broken or loose parts, or slipping belts
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Service Manual
HP2 Series Hydrostatic Tandem Pumps
7
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
HY13-1521-M1/US
General Information
Troubleshooting Checklist
Trouble
Oil Leakage
No / Low Power
Noisy Unit
Cause Remedy
Operates Hot
1. Damaged seal.
2. Air trapped in system.
1. Debris buildup.
2. Cooling fan damaged.
3. Oil level low or contaminated.
4. Excessive loading.
5. Air trapped in system.
6. Inlet leak.
Remove debris, replace seals using
seal kit p/n SK000234 for HP2 Tandem
pump.
Purge system per instructions.
Remove debris.
Replace fan.
Fill or change oil and lter.
Reduce vehicle load.
Purge per instructions.
Check all external connections to inlet.
1. Engine speed low.
2. Oil level low or contaminated.
3. Bypass loose.
4. Excessive loading.
5. Air trapped in system.
6. Inlet leak.
7. Clogged inlet lter.
8. Suspect internal damage.
Adjust setting.
Fill or change oil and lter.
Tighten.
Reduce vehicle load.
Purge per instructions.
Check all external connections to inlet.
Replace.
Disassemble and inspect.
1. Excessive speed input.
2. Oil level low or contaminated.
3. Excessive loading.
4. Air trapped in system.
5. Inlet leak.
6. Bypass loose.
Adjust input speed above 1800 rpm and
below 3600 rpm.
Fill or change oil and lter.
Reduce vehicle load.
Purge per instructions.
Check all external connections to inlet.
Tighten bypass.
7

Service Manual
HP2 Series Hydrostatic Tandem Pumps
8Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
HY13-1521-M1/US
General Information
Tools and Materials Required for Servicing
• Clean, petroleum-based solvent
• Emery paper
• Vice with soft jaws
• Air-pressure source
• Arbor press
• Flat screwdriver
• Grease pencil or paint pen
• Small gear puller
• 3/8" torque wrench: 155-190 in-lbs, 282-342 in-lbs, 90-110 in-lbs, 160-200 in-lbs
• Sockets: 3/8" drive ratchet, 5/8", 9/16" and 13mm, 11/16, 1/4" Allen, 5/16" Allen
• Allen wrenches: 1/4" and 5/16"
• Combination wrenches: 9/16" for fan part only
• Vise grip™ pliers
• Internal snap ring pliers
• Clean corrosion resistant grease. Recommended grease is Mobil Mobilith SHC
®
460 or equivalent.
• Rubber hammer
CAUTION Mixing greases that have different
bases can be detrimental to bearing
life.
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Item Description Item Description
No. No.
1 ADAPTER-EXPANSION TANK
2 THRUST BEARING
3 HOUSING SEAL RING
4 SEAL - INPUT
5 SHAFT - PUMP
SEAL - THRU SHAFT
6 CHARGE COVER
7 FAN - HYDRO
8 SWASHBLOCK
9 CONTROL BLOCK
10 RETAINING RING
11 CENTER SPRING
12 NOTAVAILABLE
13 DOWEL PIN
14 GEROTER SET
15 CHARGE RELIEF KIT
16 SEAL RING - CHARGE COVER
17 BOLT - T2-HX FL
18 WASHER
19 HEX BOLT
20 NOTAVAILABLE
21 WASHER - FAN RETAINER
22 NUT - INSERT - NYLON
23 HUB - FAN
24 THRUST WASHER
25 PISTON & BARRELASSEMBLY
26 PORT PLATE - PUMP 1
27 PORT PLATE - PUMP 2
28 HOUSING ASSEMBLY - PUMP 1
CRADLE BEARING
29 CENTER BLOCK ASSEMBLY
30 HOUSING ASSEMBLY - PUMP 2
CRADLE BEARING
31 SHAFTASSEMBLY - PUMP 1
32 NOTAVAILABLE
33 CHECK VALVE ASSEMBLY
34 FILTER - TANDEM TRANSMISSION
35 VALVE - BYPASS
36 BACKUP RING
37 O-RING
38 TRUNNION ARM
39 SEAL - TRUNNION
40 RETAINING RING
41 SEAL KIT
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
General Information
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
10

54
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Notes
10
General Information
Exploded View - Typical
4
3
2
2
8
9
5
24
3
17
6
9
33
33
1
14
30 15
19
23
22
21
19
17
16
17
17
11
25
13
27
33
33
20
13
25
11
8
17
17
17
10
18
31
17
28
13
26
29 13
INSTALL FAN WITH PART NUMBER TOWARDS PUMP
2X TORQUE 17.5-21.5 N-m
(155-190 in-lbs)
4X TORQUE 18.1-22.6 N-m
(160-200 in-lbs)
8X TORQUE 31.9-38.6 N-m
(282-342 in-lbs)
2X TORQUE 9.0-11.3 N-m
(80-100 in-lbs)
34
37 36 35
35
40 39
38
40 39
38
PARKER HP2 TANDEM PUMP
7
41 - Seal Kit
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Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Option Disassembly and Assembly
Before you disassemble the HP2 Tandem pump or any of its components, read this entire manual. It provides
important information on parts and procedures you will need to know to service the HP2 Tandem pump.
Thoroughly clean off all outside dirt, especially from around ttings and hose connections before disconnecting
and removing the HP2 Tandem pump. Remove rust or corrosion from the coupling shaft.
Remove shaft connections and hose ttings and immediately plug port holes and uid lines.
Remove the HP2 Tandem pump from the system, drain it of uid and take it to a clean work surface.
Clean and dry the HP2 Tandem pump before you start to disassemble the unit.
As you disassemble the HP2 Tandem pump, clean all parts, except seals, in clean, OSHA approved solvent, and
air blow them dry.
WARNING Since they are ammable, be extremely careful when using any solvent. Even a small explosion or
re could cause injury or death.
WARNING Wear eye protection and be sure to comply with OSHA and other maximum air pressure require-
ments.
WARNING Never steam or high pressure wash hydraulic components. Do not force or abuse closely tted parts.
Keep parts separate to avoid nicks and burrs.
Discard all seals and seal rings as they are removed from the HP2 Tandem pump. Replace all seal rings and any
damaged or worn parts with genuine Parker Hannin Corporation or OEM approved service parts.
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Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Disassembly
Removal of fan
Mark assembly for
alignment
Remove fan nut
1. Clean and remove debris from exterior of
pump to prevent contamination. Secure pump
in vise using only mounting ange to prevent
damage while servicing.
NOTE Before troubleshooting any system
problem, check service literature
published by the equipment and/or
component manufacturers. Follow their
instructions, if given, for checking any
component other than the HP2 Tandem
pump.
2. Place an alignment mark on the side of the fan
assembly and onto the top of the charge pump
cover. This will make reassembly easier.
3. Remove 3/8-24 nylon insert nut from shaft us-
ing a 9/16" wrench. Lift out special washer and
remove fan.
12
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15
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Disassembly
Remove washer
Remove fan
Remove fan
spacer
4. Due to the taper in shaft, use an open end
wrench to pry fan spacer from one side to the
other until loosened, or use a small gear puller.
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16
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Disassembly
Remove fan
spacer
Remove fan
spacer
Mark charge
pump cover to
housing
5. Place an alignment mark on the side of the
charge pump cover to housing assembly. This
will make reassembly easier.
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15

17 Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Disassembly
Remove bolts
Remove bolts
Removal of charge
cover
6. Remove two M8 x 1.25 bolts (19) on charge
end cover using a 13mm socket.
15
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18
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Disassembly
Remove seal
Remove spring
Lift off charge
pump rotor set
7. Watching for a loose ball and spring, lift off
charge pump end cover. The O-ring (16) should be
inside the base of the cover. Remove and inspect
for damage.
8. Remove spring (14) and tip pump to remove
plastic ball (15) in check valve.
9. Lift off the rotor set (stator, rotor).
CAUTION Be very careful to not scratch or
damage the charge surface on the
rear housing as this will result in
lower efciency of charge pump
when reassembled.
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19
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Disassembly
Lift off charge
pump rotor set
Ball removal
Remove filter
10. Using a small amount of grease, remove check
ball (15) from rear housing.
11. Using a 5/8" socket remove lter. Replace later
during reassembly with a new lter.
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20
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Disassembly
Check /shock
valve removal
Check /shock
valve removal
Check /shock
valve removal
12. Remove shock (33), or check (34) valves on
either side of the center block. (You will use:
- 1/4" wrench insert for check valve
- 11/16" socket on shock valves.)
NOTE Replace any valve that may have heavy
wear marks on the seat area.
NOTE Lift out valve assembly and check for
wear on valve seating surface and re-
place if necessary. Using a light source,
check seats in center block for wear
(heavy pitting marks on check valve
cavity) or deformation of sealing sur-
face.
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21 Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA
Service Manual
HP2 Series Hydrostatic Tandem Pumps
HY13-1521-M1/US
Disassembly
Check /shock
valve removal
Bypass valve
removal
Remove bypass
valves
Mark center block
to rear housing
13. Using a 5/8" socket, remove the bypass
valves.
19
20