Parker Commercial Hydraulics PGP030/031 Series User manual

Service Manual
PGP030/031 Series
PGP050/051 Series
Service Manual
HY09-SM030/031/050/051/US
Effective: August 2002
Supersedes: June 1989
new photo

2Parker Hannifin Corporation
Gear Pump Division
Youngstown, OH
FAILURE OR IMPROPER SELECTION OR IMPROPER USE OFTHE PRODUCTS AND/OR SYSTEMS DESCRIBED HEREIN OR RELATED ITEMS CAN CAUSE DEATH, PERSONAL
INJURY AND PROPERTY DAMAGE.
This document and other information from Parker Hannifin 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 its own analysis and testing, is solely responsible for
making the final 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, specifications, designs, availability and pricing, are subject to change by Parker Hannifin Corporation
and its subsidiaries at any time without notice.
WARNING
The items described in this document are hereby offered for sale by Parker Hannifin Corporation, its subsidiaries or its authorized distributors.This offer and its acceptance are
governed by the provisions stated in the “Offer of Sale”.
Offer of Sale
Service Manual HY09-SM030/031/050/051/US
Tableofcontents Series PGP 030/031 Series PGP 050/051
Use Genuine Parker Replacement Parts
DESCRIPTION PAGE NO.
General Instructions ............................................3
Disassembly instructions ..................................4-6
Assembly instructions......................................6-9
Guidelines for acceptable wear ...........................9
Tool list...............................................................10
Lubrication and oil recommendations ......... 11-12
Recommended start-up procedures
for new or rebuilt pump......................................12
Recommended test procedure..........................13
Offer of sale .......................................................14

3Parker Hannifin Corporation
Gear Pump Division
Youngstown, OH
Plug 5 in position B gives clockwise rotation.
Plug 5 in position A gives counterclock-wise rotation.
Check valves in both positions give bi-directional rotation.
Items shaded apply to
multiple assemblies only.
PARTS LIST
1. Snap Ring
2. Outboard Bearing
3. Seal
4. Shaft End Cover
5. Check Assemblies
or Plug
6. Ring Seals
7. Roller Bearings
8. Pocket Seals
9. Thrust Plates
10. Integral Drive Shaft
and Gear Set
PGP030/031/050/051
Service Manual
General Instructions
These service instructions will familiarize you with
Parker's single and multiple pumps:
•their component parts
•the relative position of each part
•proper methods for assembly or disassembly of
the units
To facilitate the repair of these units, and before
any work is done, we suggest that you first read
all of the steps used in disassembly and assembly.
Dirt is the enemy of any hydraulic system.The
first requirement of good maintenance of hydraulic
equipment is cleanliness. MAKE SURE YOU
DISASSEMBLE AND ASSEMBLE YOUR
HYDRAULIC EQUIPMENT IN A CLEAN AREA.
Our pictures show a Model PGP051. Notes in
the text cover variations between this unit and
the other models.
It is important to airblast all parts and wipe them
with a clean, lintless cloth before assembly.
11. Gasket Seals
12. Dowel Pins
(PGP031/051 only)
13. Bearing Carrier
14. Connecting Shaft
15. Matched Gear Set
16. Gear Housing
17. Port End Cover
18. Washers
19. Studs or Cap Screws
20. Nuts
A pump must be driven in the direction of rotation for
which it was built; otherwise, the pressure will blow
the shaft seal. Check the exploded view and notes at
right for proper direction of rotation.
Parker's Replacement Parts
Parker's replacement parts are of original equipment
standards. For assured quality of material and work-
manship, and for compatibility in assembly, USE
ONLY GENUINE PARTS.
It is a good idea to check all replacement parts
before installing them to be certain that they were
not damaged in shipment.
Service Manual HY09-SM030/031/050/051/US
GeneralInstructions ServiceManual Series PGP 030/031 Series PGP 050/051
USE CAUTION IN GRIPPING ALL PARTS IN THE
VISE TO AVOID DAMAGING
MACHINED SURFACES.

4Parker Hannifin Corporation
Gear Pump Division
Youngstown, OH
Start Disassembly Here
CAUTION:
1. If prying off sections becomes necessary, take extreme care not to mar or damage machined surfaces. Excessive force while prying
can result in misalignment and seriously damage parts.
2. Do not force parts during assembly, and never use an iron hammer.
3. Gears are closely matched, therefore they must be kept together as sets, when removed from a unit. Handle with care to avoid
damage to the journals or teeth.
4. Never hammer roller bearings into bores. Use only an arbor press or other suitable tool.
1) Mount the pump in a vise
with the shaft end pointing
down. Index mark all
sections with a punch. Be
sure to align these marks
when reassembling.
2) Remove the 4 cap
screws on single units,
or the 4 hex nuts, studs,
and washers on multiple
units with a socket
wrench.
3) Lift off the port end cover.
If necessary to pry loose,
refer to caution note.
If the thrust plate remains
in the gear housing, it can
be tapped out later with a
wooden hammer handle.
Be careful not to distort
the thrust plate.
4) Lift the gear housing
from the gears.Take care
not to damage machined
surfaces.
ForPGP031/051- Pry the
gear housing from the
gears and off the dowels
from opposite sides,
taking care not to
damage machined
surfaces.
For multiple assemblies only.
5) Carefully remove the
drive and driven gears,
withoutallowingtheteethto
comeintoroughhandling
contact. Keep these gears
together, because they are
a matched set. Examine
andreplaceifnecessary.
(Seepage9.)
For multiple assemblies only.
6) Lift or pry off the bearing
carrier carefully to prevent
damage to contact face
and edges.
ForPGP031/051,prythe
bearing carrieroffthe
dowelsfromopposite
sides.Takecare
nottodamagethe
machined surfaces.
Lift off the
bearing carrier.
For multiple assemblies only.
Service Manual HY09-SM030/031/050/051/US
DisassemblyInstructions Series PGP 030/031 Series PGP 050/051

5Parker Hannifin Corporation
Gear Pump Division
Youngstown, OH
7) Removethedrivegear
connecting shaft.
For multiple assemblies only.
8) Lift or pry off the first
section gear housing. Be
careful not to damage
machined surfaces. If the
thrust plate remains in the
gear housing, remove as
described in Step 3.
9) Remove the driven gear
and the integral gear and
drive shaft. Keep these
together as they are a
matchedset.Examine
andreplaceifnecessary.
Becarefulnot to damage
themachinedsurfacesof
thegears.
10) Pry the thrust plates
from the shaft end cover,
port end cover, or bearing
carrier with a screwdriver
or similar tool. Avoid
distorting the thrust plates.
Visually inspect thrust
plates for wear or damage.
Replaceifnecessary.
(Seepage9.)Removeand
discardallrubberpocket
sealsandgasketseals.
11) Examine all roller
bearings for scoring,
spalling, or pitting. If
replacement is necessary,
remove the bearings with
a bearing puller.
12) It is generally
advisable to replace ring
sealswhenrebuildingthe
unit.Toreplace,remove
thedrivegearbearing
withabearing puller,
andremovethering seal
from the bottom of the
bearing bore.
13) If the pump is
equipped with an out-
board bearing, place the
shaft end cover in a vise
with the mounting face up.
Remove the bearing snap
ring with a small
screwdriver or awl.
14) Use a bearing puller
to remove the outboard
bearing.
Service Manual HY09-SM030/031/050/051/US
DisassemblyInstructions Series PGP 030/031 Series PGP 050/051

6Parker Hannifin Corporation
Gear Pump Division
Youngstown, OH
Start Assembly Here
15) With the mounting face
down, remove the double lip
seal by inserting the special
seal removal tool (see Tool
List Pg. 10) into the notch
between the double lip seal
and the shaft end cover.Tap
the seal out and discard.
1) Stone off all machined
surfaceswithamedium-
grit,carborundum stone.
2) If the bearings have
been removed, deburr
bearing bores. Rinse
parts in a solvent.Air
blast all parts and wipe
with a clean, lintless cloth
before starting assembly.
3) Grip the shaft end
cover in a vise with the
mounting face down.
Examine the plug or the
2 check valves to be sure
that they're tightly in
place. Replacement is
necessary only if parts
are damaged. Remove
with a screwdriver or a
special check valve tool
(seeToolListpage10).
4) If plug or check valves
are being replaced, screw
in new parts tightly.Stake
the plug with a prick
punchat both ends of the
screwdriver slot and
around the edges. Screw
the check valves in tightly
with the tool. Peen edge
of hole 1/32" to 1/16" with
1-1/2" diameter steel ball.
Service Manual HY09-SM030/031/050/051/US
Disassembly/AssemblyInstructions Series PGP 030/031 Series PGP 050/051

7Parker Hannifin Corporation
Gear Pump Division
Youngstown, OH
5) ASSEMBLY STEPS 5,
6, 7, 9 AND 11 APPLY TO
THE SHAFT END
COVER, BEARING
CARRIERS, ANDTHE
PORT END COVER.
If the ring seals are being
replaced, insert into the
bottom of drive the gear
bearing bore.The notch
in the ring seal MUST BE
VISIBLE.This is a check
to be certain that the
notched side is next to
the bearing.
6) If any bearings have
been removed from the
shaft end cover, port end
cover, or bearing carrier,
replace the bearings by
pressing them into the
bearing bore with an
arbor press.
7) Before inserting a new lip
seal in the shaft end cover,
coat the outer edge of the lip
seal and its recess with
Permatex Aviation Form-A-
GasketNo.3 Non-hardening
SealanTM orequivalent.With
the metal side of the lip seal
up,pressitintothemounting
flangeside of the shaft end
cover with an arbor press and
bar(SeeTool List page10).On
thePGP030/031series, make
certain that the lip seal is fully
seatedin the recess.Onthe
PGP050/051series,donot
attempt to bottom-out the seal;
press it in only until it is flush
with the face of the recess.
Wipe off surplus sealant.
8) Check all thrust
plates for wear. Replace
ifnecessary(see page 9).
Notethatthe thrust plates
forpumpsandmotorsare
different. Pump thrust
plates have a single relief
pocket and must be
installed with this groove
on the high pressure side.
Motor thrust plates are
grooved on both sides.
ForPGP031/051,the
reliefgrooveon all the
unidirectionalthrustplates
must be towards the high
pressure (outlet) side of
thepump.
PGP030/050seriespump
andmotorplatesresemble
themotorplateillustration.
9) Grip the shaft end
cover in a vise with the
mounting face down. Cut
2pocketseals 7/32”long
from the pocket seal strip.
Grease these pocket
seals well and insert them
into the middle slots on
the reverse side of the
thrust plate.
10) With the pocket
seals facing down, place
the thrust plate over the
bearings in the shaft end
cover.Tap thrust plate
with a soft hammer to
about 1/32" from the
machined surface.
11) Cut 4 pocket seals
approximately 1/4" long from
the pocket seal strip. Insert
one pocket seal into each of
the slots in the thrust plate.
Push each pocket seal all the
way in so that it touches the
roller bearings.Tap the thrust
plate down firmly against the
machined surface with a soft
hammer. Use a sharp razor
blade to trim the exposed end
of the pocket seal square and
flush with the thrust plate.
12) Insert the splined
end of the drive shaft into
the special steel sleeve
(seeToolListpage10).
Lightly grease the drive
shaft and sleeve. Insert
the integral gear and
drive shaft with sleeve
into the shaft end cover
with a twisting motion.
Be careful not to damage
the double lip seal. Push
down carefully until the
gear rests against the
thrust plate. Remove the
steel sleeve. Insert the
driven gear.
Service Manual HY09-SM030/031/050/051/US
AssemblyInstructions Series PGP 030/031 Series PGP 050/051
motor pump

8Parker Hannifin Corporation
Gear Pump Division
Youngstown, OH
13) Grease the new gasket
seals and insert them into
the grooves in both sides
of all gear housings.
Forthe PGP031/051 -
Examinealldowelpins.
(Seepage9.)* Before
inserting a pin, makecertain
that the hole is clean and
freefromburrs.Startthe
pininto the hole gently and
straight,tapping lightly with
asofthammer.
14) Slide the first section
gear housing over the
gears and tap it with a
soft hammer until it rests
tightly against the shaft
end cover.
Be careful not to pinch the
gasket seal. Squirt oil over
the gears to provide initial
lubrication when the pump
is started.
Forthe PGP031/051-Line
up the dowels with the
matching holes. When the
parts are parallel, squeeze
them together or gently tap
alternately over dowels
with a plastic hammer until
the parts become parallel
and move smoothly
together. Do not force.
15) With the thrust plates
mounted on the bearing
carrier (as in steps 9, 10,
11), position it on the gear
housing so that the roller
bearings receive the journals
of the drive and driven
gears. Make sure that the
drain port in the bearing
carrier is on the suction or
inlet side if the unit is being
built as a pump. (Motors do
not have drain vents in the
bearing carrier.) Make sure
that the index marks are
properly aligned.
Insertdowel pins
(PGP031/051only).
For multiple assemblies only.
16) Insert the connecting
shaft in the spline of the
drive gear.
For multiple assemblies only
17) Insert the drive and
the driven gears of the
second section into their
respective bearings.
Make certain gears are
in contact with the thrust
plate face.
For multiple assemblies only.
18) Slidethesecond section
gearhousingoverthegears
and tap it tight against the
bearingcarrier with a soft
hammer.Becareful not to
pinchthegasketseal.Squirt
oiloverthegears to provide
initiallubricationwhenpump
isstarted.
For PGP031/051 line up the
dowels and the holes in the
2 castings.When parts are
parallel, squeeze them
together or gently tap
alternately over the dowels
with a plastic hammer
until parts move smoothly
together.Do not force.Insert
dowel pins (PGP031/051only).
For multiple assemblies only
19) Place the port end
cover over the gear
journals and tap tightly
against the gear housing.
Be careful not to pinch the
gasket seal.
ForPGP031/051 Align the
dowels with the holes in the
mating casting. Being
careful not to pinch the
gasket seal, tap the port
end cover lightly in the
center between bearing
bores to engage the dowels
and to move parts together
in final seating.
20) Thread the 4 fasteners
(cap screws and washers,
or studs, washers, and
nuts) into the shaft end
cover and tighten
alternately or cross-corner.
Rotate the drive shaft with
a 6" wrench to make
certain there is no binding
in the pump.
Service Manual HY09-SM030/031/050/051/US
AssemblyInstructions Series PGP 030/031 Series PGP 050/051

9Parker Hannifin Corporation
Gear Pump Division
Youngstown, OH
Guidelines for acceptable wear
Gear Housings
Wear in excess of .005" cutout necessitates
replacement of the gear housing.
Place a straight-edge across the bore. If you can slip
a .005" feeler gage under the straight-edge in the
cut-out area, replace the gear housing.
Pressure pushes the gears against
the housing on the low pressure side.
As the hubs and bearings wear, the
cutout becomes more pronounced.
Excessive cutout in a short period of
time indicates excessive pressure or
oil contamination. If the relief valve settings are within
prescribed limits, check for shock pressures or
tampering. Withdraw oil sample and check it and
the tank for dirt.
Where cut-out is moderate, .005" or less, the gear
housing is in good condition, and both ports are of the
same size, the housing may be flipped over and reused.
Gears
Any wear on the gear hubs detectable by touch, or in
excess of .002" necessitates replacement. Scoring,
grooving, or burring of the outside
diameter of teeth requires replacement.
Nicking, grooving, or fretting of teeth
surfaces also necessitates replacement.
Drive Shafts
Replace if there is any wear detectable by
touch in the seal areas or at the drive
coupling. .002" wear is the
maximum allowable.
Wear in the shaft seal areas
indicates oil contamination. Wear or damage to
splines, keys or keyways necessitates replacement.
Thrust Plates
The thrust plates seal the gear section at the sides of
the gears. Wear here will allow internal slippage,
meaning the oil will bypass within the pump. The
maximum wear allowable is .002".
Replace the thrust plates if they are
scored, eroded or pitted. Check the
center of the thrust plates where the
gears mesh. Erosion here indicates oil
contamination. Pitted thrust plates
indicate cavitation or oil aeration. Discolored thrust
plates indicate overheating, probably insufficient oil.
Dowel Pins
If either the dowel pin or dowel hole is damaged, the
pin, machined casting, or both, must be replaced.
If more than reasonable force is required
to seat dowels, the cause may be
poorly deburred or dirty parts; cocking
of dowel in the hole or improper pin-to-hole fit.
Continued on the following page
Service Manual HY09-SM030/031/050/051/US
GuidelinesforAcceptableWear Series PGP 030/031 Series PGP 050/051
22) If the unit is equipped
withanoutboardbearing,
guide the bearing into its
recess in the shaft end
cover.This is not a press
fit. Insert the snap ring
into its groove to retain
theoutboard bearing.
21)After the fasteners are
tight and you are sure
there is no internal binding,
torque the diagonally
opposite fasteners to
200 ft. lbs. (2400 in. lbs.).

10 Parker Hannifin Corporation
Gear Pump Division
Youngstown, OH
Guidelines for Acceptable Wear continued
Bearings
If the gears are replaced; the bearings must
also be replaced. Bearings should fit into the
bore with a light press fit. A near, hand-fit
is allowable.
Seals and Gaskets
Replace all of the rubber and polymer seals
whenever disassembling the pump. Include
all of the "O" rings, the pocket seals behind
the thrust plates, the shaft seal, and the gasket seals.
Check Valves
Examine the small check valves in the shaft
end cover to make sure that they are intact
and functioning. If there are no check valves
here, make sure that the high pressure side of the
shaft end cover is plugged.
Tool List
• Arbor press
•Awl
• 1-1/2" dia. steel ball
• Bearing puller (Owatonna Tool Co. MD-956 or
equivalent)
• Clean, lintless cloths
• Deburring tool (an old file with the cutting teeth
ground off)
• Machinists hammer
• Soft hammer
• Permatex Aviation Form-A-Gasket No. 3
Non-hardening SealantTM or equivalent
• Medium-grit, carborundum stone
• Oil and grease
• Snap-ring pliers
• Prick punch
• Sharp, razor blade
• Scale (1/32" for graduations)
• Small screwdriver
• Torque wrench
• Vise with 6" minimum open spread
• Bar for lip seal installation
Note: For P30/P31, use 1-3/4" dia. by 2 bar.
For P50/P51, use 2-1/2" dia. by 2" bar.
• Special steel sleeve
Service Manual HY09-SM030/031/050/051/US
Tool List Series PGP 030/031 Series PGP 050/051