Denison Hydraulics Goldcup Series Operating and installation instructions

E-Mail: [email protected] Internet: http://www.denisonhydraulics.com
Publ. LT3-00058-2 Replaces S1-AM025-A Revised 9/02
goldcup series
DENISON HYDRAULICS
P6, P7, P8S
closed circuit piston pumps
service information

2
PAGE
installation 3
typical characteristics 3
fluid connections 4
general 5
description 5
mounting 5
shaft information 5
piping 5
service information 5
recommended fluids 5
viscosity 6
viscosity index 6
temperature 6
alternate fluids 6
maintenance 6
fluid cleanliness for new installation 6
start-up procedure 6
comparison of solid contamination classification system 7
troubleshooting 7
assembly tool drawings, T1, T2, T3, T4, T5 9
disassembly 11
rework of wear parts 12
assembly 13
drive shaft and bearing 13
barrel and auxiliary drive shaft 13
rocker cam 15
pistons and shoes 16
mounting flange, cam & cradle 16
housing 17
housing, end cap, cam and barrel 17
port block 18
mounting port block to housing 18
gerotor and barrel holddown 19
valve block (before 7-93) 20
valve block (after 7-93) 22
valve block for special mounting of servo valve (before 7-93) 26
valve block for special mounting of servo valve (after 7-93) 29
output controls 32
input controls 32
shaft and seal installation 33
mechanical shaft seal assembly procedure 33
counter-balance servo stem 34
rear drive adapter 34
pilot valve 36
shuttle valve 36
shuttle valve mounting 37
important instructions 38
instructions for replenishing circuit isolation plug 38
hydraulic circuit 40
test procedure 41
general requirements 41
basic pump test 41
(refer to manual S1-AM030 for controls service information)
ordering code 43
seal kits
complete S23-15092
valve block S23-00135
HI-IQ valve block S13-04226
shaft seal replacement S23-44302
shaft seal 623-00006
shuttle valve S23-15089
Note: New revisions are shown underlined.
Pages are marked Revised where changes have been made.
CONTENTS

3
TYPICAL CHARACTERISTICS Specification Term P 6 P7 P8
• displacement at max. angle in.3/rev. 6.00 7.25 8.00
cm3/rev (98) (119) (131)
• pressure ports A & B max. psi 5000 5000 3600
continuous bar (345) (345) (248)
max. intermittent psi 6000 6000 4350
bar (414) (414) (300)
• speed, max. continuous rpm 3000 3000 1800
• flow, ports A or B @ 1500 RPM gpm 38.9 47.1 51.9
(theoretical ) L/min. (147) (178) (196)
• flow, ports A or B @ 1800 RPM gpm 46.8 56.9 62.3
(theoretical ) L/min. (177) (214) (236)
• flow, internal replenishing pump gpm 6.9 6.9 6.9
@ 1800 RPM (theoretical ) L/min. (26.1) (26.1) (26.1)
• flow, auxiliary pump, external gpm 9.3 9.3 9.3
at 1800 RPM (theoretical) L/min. (35.2) (35.2) (35.2)
(see note)
• replenishing pressure psi 200 200 200
bar (14) (14) (14)
• servo pressure psi 335-535 335-535 335-535
bar (23-37) (23-37) (23-37)
• mounting-2 bolt flange SAE C C C
• shaft-spline SAE C C C
keyed
• fluid connection ports A & B in 1-1/2 1-1/2 1-1/2
SAE-4 bolt pad for 6000 mm (38.1) (38.1) (38.1)
split flange
• weight w/rotary servo lbs. 335 335 335
kg. (152) (152) (152)
Note: Any SAE-A or B mount pump may be used with the appropriate external drive
INSTALLATION
The product information, specifications, and descriptions contained in this publication have been
compiled for the use and convenience of our customers from information furnished by the man-
ufacturer; and we can not, and do not, accept any responsibility for the accuracy or correctness
of any description, calculation, specification, or information contained herein. No such descrip-
tion, calculation, specification, or information regarding the products being sold has been made
part of the basis of the bargain, nor has same created or amounted to an express warranty that
the products would conform thereto. We are selling the goods and merchandise illustrated
and described on this publication on an "as is" basis, and disclaim any implied warranty,
including any warranty of merchantability or warranty of fitness for any particular purpose
whatsoever, with respect to the goods and merchandise sold. All manufacturer warranties
shall be passed on to our customers, but we shall not be responsible for special, indirect, inci-
dental, or consequential damages resulting from the use of any of the products or information
contained or described on this publication. Further, we reserve the right to revise or otherwise
make product improvements at any time without notification.

4
port size function
A 1 1/2" 4 bolt SAE 6000 psi inlet/outlet
AG, BG SAE - 6 straight thread system pressure gage, ea. side
B 1 1/2" 4 bolt SAE 6000 psi outlet/inlet
C SAE - 16 straight thread internal auxiliary pump inlet
D1, D2 SAE - 12 straight thread case drain
D3 SAE - 16 straight thread replenishing relief drain
DG SAE - 6 straight thread case pressure gage
DS SAE - 4 straight thread shuttle repl. pilot drain (ext.drain)
FA, FB 1/4 - 18 dryseal NPTF control pressure gage, ea. side
G SAE - 8 straight thread int. aux. pump outlet to filter
H SAE - 8 straight thread filter return
I SAE -16 straight thread inlet to optional pump (gear pump)
SAE - 1 1/4 3000 psi, 4-bolt pad optional - vane pump
K SAE -16 straight thread aux. replenishing port
KA SAE - 12 straight thread aux. repl. inlet to shuttle
KG SAE - 6 straight thread replenishing pressure gage
M SAE - 8 straight thread auxiliary servovalve drain
S SAE - 8 straight thread servovalve inlet
VA/VB SAE - 4 straight thread individual compensator vent
Conversion Adapter Kit “A” mount S23-12438-0
“B” mount S23-12669-0
INSTALLATION
Revised

5
GENERAL The DENISON HYDRAULICS Goldcup 6, 7, and 8 axial piston pumps feature advance
design concepts which are time proven and provide for advance pumping and control
concepts. The instructions contained in this manual cover complete disassembly and
reassembly of the unit. Before proceeding with the disassembly or reassembly of any
unit, this manual should be studied in order to become familiar with proper order and
parts nomenclature.
DESCRIPTION The use of a rocker cam to control the pump displacement provides a small package
size, reduces wear, and speeds control response. The control vane actuator eliminates
linkage and backlash inherent in typical stroking cylinder designs.
Standard controls for the Goldcup units are Rotary Servo and Compensator Override.
Additional optional controls are also available.
MOUNTING This pump is designed to operate in any position.The mounting hub and four bolt mount-
ing flange are in full conformance with SAE standard.The pump shaft must be in align-
ment with the shaft of the driven load and should be checked with a dial indicator. The
mounting pad or adaptor into which the fluid pump pilots must be concentric with the pump
shaft to prevent bearing failure. This concentricity is particularly important if the shaft is
rigidly connected to the driven load without a flexible coupling.
SHAFT INFORMATION Splined: The shafts will accept a maximum misalignment of 0.006" TIR (.15 mm).
Angular misalignment at the male and female spline axes must be less than ±.002” per
inch radius (.002 mm per mm radius).The coupling interface must be lubricated. DENI-
SON HYDRAULICS recommends lithium molybdenum disulfide or similar grease. The
female coupling should be hardened to 27-45 Rc and must conform to SAE-J498B
(1971) Class 1 flat root side fit.
Keyed: High strength heat treated keys must be used.Replacement keys must be hard-
ened to 27-34 Rc.The key corners must be chamfered .030"-.040" (.75-1 mm) at 45° to
clear radii that exist in the keyway.
Splined or Keyed: Both types of shafts will accept a side load of 170 lbs. (77 kg) at the
center of the spline or key, with a B10 life of 10,000 hours at 1800 RPM.
PIPING Connect inlet and outlet lines to the port block of the pump.
The maximum case pressure is 75 PSI (5.17 bar) continuous, 125 PSI (8.6 bar) inter-
mittent.Case pressures must never exceed inlet pressure by more than 25 PSI (1.7 bar).
When connecting case drain line make certain that drain plumbing passes above high-
est point of the pump before passing to the reservoir. If not, install a 5 PSI (.3 bar) case
pressure check valve to be certain the case is filled with oil at all times.
The case leakage line must be of sufficient size to prevent back pressure in excess of 75
PSI (5.7 bar) and returned to the reservoir below the surface of the oil as far from the
supply suction as possible. All fluid lines, whether pipe, tubing, or hose must be adequate
size and strength to assure free flow through the pump. An undersized inlet line will pre-
vent the pump from reaching full speed and torque. An undersized outlet line will create
back pressure and cause improper operation. Flexible hose lines are recommended. If
rigid piping is used, the workmanship must be accurate to eliminate strain on the pump
port block or to the fluid connections. Sharp bends in the lines must be eliminated wher-
ever possible. All system piping must be cleaned with solvent or equivalent before
installing pump. Make sure the entire hydraulic system is free of dirt, lint, scale, or other
foreign material.
SERVICE INFORMATION These hydraulic products are designed to give long dependable service when properly
applied and their systems properly maintained. These general instructions apply to typi-
cal systems. Specific instructions for particular equipment can be developed from them.
RECOMMENDED FLUIDS See DENISON HYDRAULICS bulletin SPO-AM305 for more details.
Caution: Do not use galvanized pipe. Galvanized coating can flake off with
continued use.
INSTALLATION
Revised

6
FILLING CASE It is essential to make certain that the case (pump housing) is as full of fluid as possible
and remains full during operation and at rest.
Always fill to the highest available point. Remove a plug or screw and allow the oil to
escape through this point.
Recommended fill points:
Mounting orientation vertical, shaft up.D1 or D2 (drain) port in housing
Vent DG2 port in mounting flange (new units)
or one of the upper screws which attach the
control. See installation drawing.
Vertical, shaft down 1) or horizontal D1 or D2 (drain port in housing.
drain ports to the side 1) Vent DG (case gage) port in port block.
MAINTENANCE This pump is self-lubricating and preventative maintenance is limited to keeping system
fluid clean by changing filters frequently. Keep all fittings and screws tight. Do not oper-
ate at pressures and speeds in excess of the recommended limit. If the pump does not
operate properly, check the Trouble Shooting Chart before attempting to overhaul the
unit. Overhauling is relatively simple and may be accomplished by referring to the
Disassembly, Rework Limits of Wear Parts and Assembly Procedures.
Fluid must be cleaned before and continuously during operation by filters that maintain a
cleanliness level of NAS 1638 Class 8.
START UP PROCEDURE •Read and understand the instruction manual. Identify components and their function.
•Visually inspect components and lines for possible damage.
•Check reservoir for cleanliness and drain and clean as required.
•Check fluid level and fill as required with filtered fluid at least as clean as that recom-
mended. Fill pump case with clean oil prior to starting.
•Check alignment of drive.
•Check oil cooler and activate it, if included in circuit. Check fluid temperature.
•Reduce pressure settings of relief valve.Make sure accurate pressure readings can be
made at appropriate places.
•If solenoids in system, check for actuation.
•Start pump drive. Make sure pump and motor fill properly.
•Bleed system of air. Recheck fluid level.
•Cycle unloaded machine at low pressure and observe actuation (at low speed, if
possible).
•Increase pressure settings gradually in steps. Check for leaks in all lines especially in
pump and motor inlet lines.
•Make correct pressure adjustments.
•Gradually increase speed. Be alert for trouble as indicated by changes in sounds, sys-
tem shocks and air in fluid.
•Equipment is operational.
FLUID CLEANLINESS
INSTALLATION
Revised

7
TROUBLESHOOTING
TROUBLESHOOTING Component problems and circuit problems are often inter-related. An improper circuit
may operate with apparent success but will cause failure of a particular component with-
in it.The component failure is the effect, not the cause of the problem.
This general guide is offered to help in locating and eliminating the cause of problems by
studying their effects:
effect of trouble possible cause fault which needs remedy
noisy pump air in fluid leak in suction line
leak at shaft seal
low fluid level
turbulent fluid
return lines above fluid level
gas leak from accumulator
excessive pressure drop in the inlet line from a
pressurized reservoir
suction line strainer acting as air trap
cavitation in fluid too cold
pump or motor fluid too viscous
rotating group fluid too heavy
shaft speed too high
suction line too small
suction line collapsed
suction strainer too small
suction strainer too dirty
operating altitude too high
boost or replenishment pressure too low
replenishment flow too small for dynamic conditions
misaligned shaft faulty installation
distortion in mounting
axial interference
faulty coupling
excessive overhung loads
mechanical fault piston and shoe looseness or failure
in pump bearing failure
incorrect port plate selection or index
eroded or worn parts in the displacement control
erosion on barrel air in fluid see above
ports and port cavitation see above
plate
high wear in excessive loads reduce pressure settings
pump and motor reduce speeds
contaminant improper filter maintenance
particles in fluid filters too coarse
introduction of dirty fluid to system
reservoir openings
improper reservoir breather
improper line replacement

8
TROUBLESHOOTING
effect of trouble possible cause fault which needs remedy
high wear in Improper fluid fluid too thin or thick for operating temperature range
pump and motor breakdown of fluid with time/temperature/shearing
(continued) effects
incorrect additives in new fluid
destruction of additive effectiveness with chemical
aging
improper repair incorrect parts
incorrect procedures, dimensions, finishes
unwanted water condensation
in fluid faulty breather/strainer
heat exchanger leakage
faulty clean-up practice
water in makeup fluid
pressure shocks cogging load mechanical considerations
worn relief valve needed repairs
worn needed repairs
compensator
slow response in replace or relocate
check valves
servo pressure increase pressure and check pressure drop
too low to through servo filter
maintain firm
control
excessive improve decompression control
decompression
energy rates
excessive line reduce line size or lengths
capacitance eliminate hose
(line volume,
line stretch,
accumulator
effects)
barrel blow-off re-check pump hold-down, rotating group, drain
pressure
heating of fluid excessive pump recheck case drain flow and repair as required
or motor fluid too thin
leakage improper assembly, port timing
relief valve set too low (compared to load or to compensator)
instability caused by back pressure, worn parts
compensator set too high (compared to relief)
worn parts
pump too large select smaller pump displacement
for fluid needs
heat exchanger water turned off or too little flow
water too hot
fan clogged or restricted
efficiency reduced by mud or scale deposits
intermittent hydraulic fluid flow
reservoir too little fluid
entrained air in fluid
improper baffles
insulating air blanket that prevents heat rejection
heat pickup from adjacent equipment
TROUBLESHOOTING
(continued)

9
ASSEMBLY TOOL DRAWINGS
Note: Dimensions in ( ) are mm.
T-1
T-2
MATERIAL
CRS 1" DIA. X 2 5/8"
(25.4mm) (66.68 mm)

10
ASSEMBLY TOOL DRAWINGS
Note: Dimensions in ( ) are mm.
Material:
OHTS 5 5/8 x 1 1/4 DIA
(130.17) x (31.75)
HardenedTip RC 58-62
T-3
T-4
T-5

11
INTRODUCTION The instructions contained in this section cover a complete teardown of the subject
pump. Disassemble only as far as necessary to replace or repair any worn parts.
DISASSEMBLY Position pump unit so that valve block assembly is on top.A bench or similar suitable sur-
face capable of supporting unit should be used. Disassembly area should be clean.
VALVE BLOCK See figure 14. Remove the eight hex. head cap screws (17) and lift the entire block
assembly from the port block.
See figure 12/13. Remove the four hex. head cap screws (58) and four soc. hd. screws
(53) and lift the entire block assembly from the port block.
See figure 10. Remove the four screws (39) to separate the cover (21) from the block
(11). Do not remove the check valves (19).
Remove plugs (43), (36) and pin (40). Remove the 8-32 nut from the bottom of cover (21)
to remove filter assembly (34).
Remove housing (29) and O-ring (28). Remove items (30), (31), (32) and (33) as a unit.
Insert a small brass rod thru the hole in the housing and tap out piston (27) and O-ring
(26).
Remove spring (25) and cone (24). Remove seat (23) and O-ring (22).
Note: Seat is made for hex. wrenching. Use 1/2" six point socket with 1/4" drive.
Remove O-ring (37) and replenishing relief valve (41). Inspect orifices (12) visually to
insure they are open. Do not remove unless damage or clogging is apparent.
Remove springs (16), (17) and (18). Remove retainer (15) and poppets (13) and (14).
Remove the four screws (4) from the plate (6) and (11). Remove gasket (7).
Remove seats (8) and (9). Do not remove roll pins (5) and (10) unless replacements are
needed.
See figure 11. Remove plugs (20), (23) and pin (21). Remove the 8-32 nut from the bot-
tom of block (1) to remove filter assembly (14). Do not remove the check valves (2).
Remove housing (8), O-ring (9), piston seal (10), O-ring (11), screw (6), nut (7), and
acorn nut (45) as a unit.
Remove spring (12) and cone (13). Remove seat (5) and O-ring (4).
Note: Seat is made for hex. wrenching. Use 1/2" six point socket with 1/4" drive.
Remove plug (25) and replenishing relief valve (36).
Remove O-rings (37), (48) and (47). Remove four screws (43) and remove the retainer
plate (42). Do not remove roll pins (46) unless replacements are needed.
Remove gasket (29) and seats (27) and (28). Remove poppets (30), (31) and springs
(32), (33), (35) and retainer (34).
Inspect orifices (3) visually to insure they are open. Do not remove unless damage or
clogging is apparent.
CONTROLS See figure 14. Remove the four screws (14) from the side cover (16) and remove the
input shear seal valve assembly
Note: The myltite washers (13) should be replaced at assembly.
Remove the four screws (14) from the side cover (15) and remove the counter balance
shear seal assembly.
Remove the two screws (12) and remove the balance stem (9) and balance plate (10)
See figure 14. Remove two screws (20) and remove external pump (21).
Remove four screws (23) and remove shuttle valve (24).
Remove four screws (9) fig. 15 and remove adapter (22).
See figure 9. Remove retainer ring (16), pin (14), holddown nut (13), insert (15), thrust
washers (10), bearing (11) and seal ring (12).
Remove pressure plate (9), Gerotor side plate (5) “O” rings (7) and (8).
Remove Gerotor assembly (3), dowel pin (4), key (2), and side plate (1).
BARREL HOLDDOWN AND
GEROTOR ASSEMBLY
EXTERNAL PUMP, SHUTTLE
VALVE AND REAR ADAPTER
(after 7-93)
(before 7-93)
UNIT DISASSEMBLY

12
PORT BLOCK See figure 8. Remove four screws (1) that secure the port block (2) to the housing (6).Use
caution when removing screws on valve block side to prevent marring valve block face.
Remove port block (2) and gasket (5). Remove port plate (4) and port plate pins (3).
Note: port plate will in some instances adhere to port block upon disassembly.
See figure 7. Remove the check valve assemblies (7) from the port block.
Remove needle bearing (2) from the port block.
Remove two screws (5), lockwashers (6), check rings (3), and clamps (4). Only one
check ring assembly in open circuit pumps.
BARREL AND AUXILIARY SHAFT Remove face plate (2, fig. 6) from face of barrel assembly.
Remove the barrel assembly (1, fig. 4) by grasping the auxiliary shaft and lifting the com-
plete assembly out of the housing.
DRIVE SHAFT See figure 14. Remove the four screws (8) and gaskets (7). Remove seal retainer (6),
and the stationary part of the shaft seal (4). Refer to view of item 4.
Carefully remove the carbon ring and the remainder of the shaft seal from the shaft.
Caution: Do not scratch seal surface of shaft when removing seal.
Remove snap ring (3) and the shaft and bearing assembly (1). Remove shim (2).
HOUSING After shaft assembly has been removed, position the unit on end with the mounting
flange turned down.
Push the ends of the small tube lines away from the housing.
Lift the housing from the mounting flange, remove the gasket, and dowel pins from the
mounting flange.
Do not remove the roll pins and the bearing from the housing unless the bearing is dam-
aged and must be replaced.
See figure 4. Remove the complete assembly (5) from the mounting cap (7) and posi-
tion on a clean flat surface with the two tubes (2) in a horizontal position and located at
the top. Mark the cam (24) and cradle (20) as indicated in Figure 3. These marks will
determine positioning of parts during reassembly.
Carefully remove the small tube lines (3) and (4) from the cradle.
Caution: Do not bend these lines
See figure 3. Position the assembly in an upright position on the flat surface of the cra-
dle (20). Remove the retaining ring (1) and thrust washer (2). Remove the piston and
shoe assembly (4) and the creep plate (5) from the cam (24). Carefully remove the two
set screws (6a) and two screws (6) that secure the servo plate to the cam (24) and
remove the servo input parts (7, 8 and 9).
Remove the four 7/16" screws (10) and eight 1/4" screws (11) and (12) from the control
covers (15R) and (15L). Remove the four dowel pins (16) and remove the two chambers
(17). Remove the two special seals (18) and the four steel balls (19). Remove the two
vane seal cartridge assemblies (23) and the four holddown vanes (22) from the rocker
cam (24).
Remove the rocker cam (24) from the cradle (20).
Caution: Do not remove the plugs from the rocker cam.
Note: Some units may have thin shims under the holddown vanes.
ROCKER CAM AND CONTROL
STROKING ASSEMBLY
UNIT DISASSEMBLY
BARREL AND AUXILIARY SHAFT

13
max. rework
6, 7.25 and 8.0 in3from original min. dimension after rework
port plate face .010” (0,254 mm) .295” (7,49 mm)
shoe retainer face .005” (0,127 mm) .307” (7,8 mm)
piston shoe face .006” (0,152 mm) .008” (0,2 mm)
(pocket)
creep plate face .005” (0,127 mm) .286” (7.13 mm)
face plate none replace
IMPORTANT:
The port plate both faces finish must be 25 microinches (635 mm), flat within .00006
(0015 mm) and parallel within .001(0254 mm) T.I.R.
The creep plate wear face finish must be 10 microinches (254 mm), flat within .0002
(0381 mm) and parallel to the backside within .0005 (0127 mm)T.I.R.
The shoe retainer wear face finish must be 32 microinches (813 mm), and flat within
.0015 (0381 mm) (must not be convex).
The piston shoes wear face finish must be 5 microinches (127 mm), and must be lapped
in a set with the retainer plate, all shoe sole thicknesses to be within .001 (0254 mm) after
lapping.The maximum permissible shoe and piston axial looseness is .010 (254 mm).
The special retaining ring service kit (S23-12461) may be required to control shoe
holddown clearance.
REWORK LIMITS OF WEAR
PARTS
UNIT DISASSEMBLY

14
CLEANING AND INSPECTION All parts must be inspected and be free of material defects, dirt, scratches or any foreign
material.
All parts must be cleaned with a suitable cleaning solvent and all holes and passages
blown out with dry, clean, compressed air.
After cleaning and inspection, all parts must be covered with a light film of oil and pro-
tected from dirt and moisture. Excessive handling of internal parts should be avoided
prior to assembly.
During assembly, lapped and ground surfaces must be lubricated with clean oil and pro-
tected from nicks or surface damage.
DRIVE SHAFT AND BEARING See figure 1. Pass one retaining ring (3) over the internal end of drive shaft (1) and install
in the groove near the shaft seal surface.
Caution: Do not pass the ring over the seal surface.
Press the bearing (2) over the same end of the shaft and seat against the ring.
Support only the inner race of the bearing and press on the coupling end of the shaft.
Caution: Do not use excessive force and distort or damage the retaining ring.
Install the other retaining ring (3) in the other retaining ring groove. Be sure that both
rings are fully seated.
PARTS LIST FOR FIGURE 1
S13-41805 DRIVE SHAFT ASSEMBLY (SPLINED)
S13-41806 DRIVE SHAFT ASSEMBLY (W/KEYWAY)
quantity
item description part no. #3 #2
1 #3 (splined shaft) 033-70567 1 -
#2 (keyed shaft) 033-70579 - 1
2 shaft bearing 230-82140 1 1
3 retaining ring 033-70817 2 2
4 square key 5/16 x 1-1/4 033-71348 - 1
See figure 2. Position the barrel (1) in a press with the large end turned down and insert
tool figure T-1 in the splined shaft hole in the barrel.
Place stop (3) and spring (4) over shaft (2) in the same sequence as shown.
Insert shaft (2) in barrel (1) and rest on tool figureT-1.Position the spring retainer (5) over
the shaft (2) and against spring (4).
Carefully place tool figure T-2, with the large end of the tapered hole up, over the shaft
(2) and against the barrel face (1). Insert ring (6) around the shaft (2) and in the tool.
Position the ring with the gap within 5/8" (16 mm) of the notch in the barrel for easy
removal.
Place tool figure T-3 over the shaft (2) with the small end against ring (6). Press on the
end of the assembly tool and seat the ring (6) in the groove of the barrel (1).
Remove the assembly tools.Check to be sure that the ring is properly seated.Check bar-
rel face to be certain it is not marred.
PARTS LIST FOR FIGURE 2
S23-12363 P6 COMPLETE BARREL AND SHAFT ASSEMBLY
S23-12500 P7 COMPLETE BARREL AND SHAFT ASSEMBLY
S23-12717 P8 COMPLETE BARREL AND SHAFT ASSEMBLY
quantity
item description part no. P6 P7 P8
1 barrel & sleeve ass’y (P6) S13-43657 1 - -
barrel & sleeve ass’y.(P7) S13-47511 - 1 -
barrel & sleeve ass’y (P8) S23-12718 - - 1
2 auxiliary drive shaft 033-91050 1 1 1
3 stop 033-53944 1 1 1
4 barrel holddown spring 033-70493 1 1 1
5 spring retainer 033-53945 1 1 1
6 retaining ring 033-70494 1 1 1
Consult DENISON HYDRAULICS Service for parts prior to 1983 units.
BARREL AND AUXILIARY
DRIVE SHAFT
ASSEMBLY PROCEDURES
Figure 2
Figure 1

15
PARTS LIST FOR FIGURE 3
rocker cam, pistons and retainer
item description part no qty.
1 retaining ring (yellow) .083" (2.11 mm) 033-70484 1
retaining ring (green) .081" (2.06 mm) 033-70488
retaining ring (red) .079" (2.01 mm) 033-70490
retaining ring (white) .087" (2.21 mm) 033-72175
retaining ring (blue) .085" (2.16 mm) 033-72176
retaining ring (black) .077" (1.96 mm) 033-54826
retaining ring service kit S23-12461
2 thrust washer 033-72249 1
3 not used
4 piston & shoe assy. w/retainer See below
5 creep plate 033-71261 1
6 button hd. screw 353-25041 2
6a setscrew, 2 ea. 312-09032 2
7 servo stem 033-71312 2
8 orifice screw 033-70819 2
9 servo plate 033-53874 1
*10 hex. hd. screws 7/16-14 x 2-1/2 306-40183 4
*11 hex. hd. screws 1/4-20 x 1-1/4 306-40188 4
*12 hex. hd. screws 1/4-20 x 2-1/4 306-40187 4
*13 hex socket plug SAE-4 488-35001 2
*14 O-ring 90-6290-4 691-00904 2
*15R right side chamber cover CW rot. 033-70572 1
right side chamber cover CCW rot. 033-70612
*15L left side chamber cover CW rot. 033-70571 1
left side chamber cover CCW rot. 033-70574
*16 dowel pin 1/4 x 1-1/2 324-21624 4
*17 chamber 033-72266 2
*18 seal 606-25036 2
*19 steel ball 3/16 201-06001 4
*20 rocker cradle 033-53951 1
*22 hold down vane 033-70816 4
*23a -seal backup plate 033-70802 4
*23b -vane seal 033-70501 2
*23c -O-ring 90-914-20 691-00120 2
*23d -spacer 033-70519 2
*23e -check valve 033-70803 2
*24 rocker cam S23-12105 1
25 pressure tube 033-70524 2
*Note: Item 10 through 24 can be ordered as a complete rocker cam & control stroking
assembly.
S23-12196 is for RH pumps
S23-12197 is for LH pumps
item description P6S P7S P8S qty.
4 piston & shoe assy. S13-43655 S13-42308 S21-11650 1
w/retainer
4a shoe retainer 033-54290 033-54290 033-57376 1
4b piston & shoe assy. S13-45680 S13-46040 S21-11649 7
ASSEMBLY PROCEDURES

16
ROCKER CAM/PISTONS
AND RETAINER
ROCKER CAM See figure 3. Position the cradle (20) on a clean flat surface with the large flat area down.
Position the rocker cam (24) on the cradle (20). Note marks made earlier to indicate top
of rocker cam & cradle.
Place O-ring (23c) around spacer (23d) and insert in the vane seal (23b).
Insert check valve (23e) inside of spacer (23d) and assemble between the two backup
plates (23a) with the notched V’s exposed.
Install assembled cartridge in slot in cam as indicated in Figure 3.Repeat steps 1, 2 and
3 on other side of cam.
Insert the four holddown vanes (22) in the slots on each side of the control vanes (23).
Position both control chambers (17) on a clean flat surface with seal grooves turned up.
Drop the four steel balls (19) in the four counterbored holes at each end of the seal
grooves.
Lubricate seals (18) and insert in seal grooves in control chamber (17).
The tapered side of the seals must be pushed into the grooves and the ends must cover
the steel balls.
Install the control chamber (17) with seal (18) and steel balls (19) assembled over the
control vane (23).The seal must be against the cam. Rotate the chamber until it passes
over the control vane assembly, then rotate in the opposite direction until the 1/4" dowel
pins (16) can be pushed through the chamber (17) and into the cradle (20).Install cham-
ber in the same manner on the other side of the cam.
Two sets of chamber covers are available.The set marked CW must be installed in the
right hand rotation pump and the set marked CCW must be used in the left hand rota-
tion pump. (Rotation is determined facing the shaft end of pump.) The covers must be
installed with the tubing holes and the tapped holes at the top of the unit. Install cham-
ber covers (15r) and (15l) on the control chambers (17) over the dowel pins (16). The
tapped holes must be at the top. Refer to the “T” marked on the rocker cam (24) and cra-
dle (20).
Install four 1/4-20 screws, two (11) and two (12), in each side and torque to 10 ft.-lbs.
(13.56 Nm)
Install two 7/16-14 screws (10) in each side and torque to 45 ft.-lbs. (61.0 Nm)
Install O-ring (14) and plug (13) in each cover.
ASSEMBLY PROCEDURES
Figure 3
Note: Install items 6, 7, 8, and 9 on side shown of rocker
cam if pump model number has “B” suffix. Install on
opposite side if “A” suffix.
Marks Designate
Top of Assembly

17
Install tubes (25) in reamed holes in each cover.These tubes must be a tight fit. If tubes
are loose, the ends can be expanded with a tapered punch.
Tap the tubes in place with a plastic mallet.
Install two orifice screws (8) in the servo stem (7).
Install servo plate with the end of the screws (6) through the servo stem. The orifice
screw end of the servo stem must be against the servo plate.
Position the stem and plate on the rocker cam input side at 9 o’clock position on “B” suf-
fix or 3 o’clock on “A” suffix models with the screws positioned over the 10-24 tapped
holes.Torque the screws (6) to 40 in. lbs. (4.5 Nm). Install setscrews (6a) and torque to
5 ft.-lbs. (6.8 Nm). Caution: The set screws must not protrude from the servo plate.
Install creep plate (5) over center post on rocker cam with small O.D. of plate turned
toward cam.
PISTONS AND SHOES See figure 3. Insert the seven piston and shoes (4b) in the shoe retainer (4a). Position
the assembly (4) over the center post and against the creep plate.
Install thrust washer (2), over center post.
Five different retaining rings (1) are available for the holddown assembly. Each ring is
marked; white dot .087 (2.21 mm) thick, blue dot .085 (2.16 mm) thick, yellow dot .083
(2.11 mm) thick, green dot .081 (2.06 mm) thick, and red dot .079 (2.01 mm) thick.Install
the thickest ring (1) with the dot up, that will fit in the groove on the center post and allows
a maximum clearance of .002-.004 (.051-.102 mm) between the shoe and creep plate
while grasping one piston and lifting tightly against shoe retainer.
The piston and shoe assembly (4) must be free to rotate easily by hand. The assembly
must be rotated through 360° to confirm there is no binding and that each shoe is always
free in the retainer plate. Oil the assembly thoroughly.
Position the cradle and cam assembly with the piston and shoe assembly attached with
T marked on the cradle turned up.
See figure 4. Insert tube line assemblies (3 and 4) in the holes provided in cradle.
Note: Tube assemblies (3 & 4, fig.4) must be a snug fit into holes in cradle. Expand end
of tubes with a pointed tool to assure fit.
Position the mounting flange (7) with the large open end up, and install two dowel pins
(6) in the cradle mounting surface of the flange and two dowel pins (6) in the outer edge
of the flange.
Install rocker cam and cradle assembly over the two dowel pins (6) in the mounting
flange.Be certain that cradle is seated over the pins and against the flange with the tube
lines (3) and (4) in the grooves in the flange.
Position the mounting flange with the rocker cam assembly installed on the top or bottom
side and install two or more 1/4-20 x 1-1/4" screws through the seal retainer area into the
cradle. Be certain the cradle is fully seated in flange.These screws are required to hold
the rocker cam assembly in place and will be removed later.
Return the assembly to an upright position with the mounting flange down.
Tilt the rocker cam to either extreme position in the cradle.
Position the Barrel Assembly with Auxiliary Shaft (1) directly over the pistons. Start with
the uppermost piston and guide them one at a time into the barrel.Return the rocker cam
to a level position in the cradle.
PARTS LIST FOR FIGURE 4
item description part no. qty.
1 barrel and auxiliary shaft assy. See fig. 2 1
2 pressure tube 033-70524 2
3 tubing assy. (right side) S13-42402 1
4 tubing assy. (left side) S13-42403 1
5 rocker cam and stroking assy. See fig. 3 1
6 dowel pin 3/8" X 3/4" 324-22412 4
7 mounting flange 033-70604 1
MOUNTING, FLANGE, CAM &
CRADLE, BARREL
ROCKER CAM
(continued)
ASSEMBLY PROCEDURES
Figure 4
See
Fig. 3

18
HOUSING See figure 5. Position housing (1) on a clean flat surface with the large open end up.
Wash and dry all parts. During assembly, lapped and ground surfaces should be kept
lubricated with clear oil and protected from nicks or surface damage.
Clean housing, item #1, and barrel bearing, item #2. Apply loctite primer grade "T" & loc-
tite retaining compound #609 to bearing O.D. & bearing bore of housing. Rest housing
on mounting flange end.
Position notch on bearing (2) with hole in housing bore. Insert Pressing Plug tool (figure
T-4) in the bearing. With smooth and steady force, press the bearing into the housing
bore until seated. DO NOT HAMMER OR BEAT INTO PLACE.
Install bearing retainer (7) with O-ring (8).Torque to 50 lb.-ft. (68 Nm).
Turn housing (1) on side and install roll pin (4) in the 1/4" through hole in the control cover
pad. The pin must be 3/8" below the pad surface. THE PIN END MUST NOT INTER-
FERE WITH THE INTERNAL BEARING CAGE. Install two dowel pins (3) in the blind
holes in the same pad.
Repeat the above step on the opposite side of the housing.
Place O-ring (5) on plug (6) and install in bottom of housing (1). (Roll pins (4) are in bot-
tom of housing.)
PARTS LIST FOR FIGURE 5
item description part no. qty.
1 housing 033-91108 1
2 bearing 033-91107 1
3 dowel pin 324-21608 4
4 roll pin 325-16280 2
5 O-ring 90-6290-12 691-00912 1
6 hollow hex plug SAE-12 488-35014 1
7 retainer-bearing 033-91106 1
8 O-ring, 90 S-1 ARP 908 691-00908 1
See figure 6. Insert the three face plate pins (1) in the holes provided in the barrel face.
Apply heavy grease to the face of the barrel and install the face plate (2) over the pins
(1) in the barrel.
Make certain the face plate is properly seated on the barrel and pins with the steel
side towards the barrel face. The face plates have only one side bronzed and this
should be toward the port plate. If necessary, remove coating from edge of face plate
to determine bronze side.
Install gasket (3) over the two dowel pins (item 6 on Fig. 4) in the mounting flange.
Position the Housing Assembly (4) over the Barrel and Auxiliary Shaft Assembly and
carefully guide the pressure tubes and tube lines (items 2, 3 and 4 on Fig. 4) through the
Housing Assembly (4).
PARTS LIST FOR FIGURE 6
item description part no. qty.
1 face plate pins 033-49825 3
*2 barrel face plate 6 in3 only 033-71530 1
barrel face plate 7.25 and 8.0 in3033-72532 1
3 housing gasket 033-91067 1
4 housing assembly See fig. 4 1
*Note: item 2: (Ref. only) Arcuate port width: 6 in3is 13/32" (10,3 mm), 8.0 & 7.25 in3is
1/2" (12.7 mm)
HOUSING, END CAP, CAM
AND BARREL
ASSEMBLY PROCEDURES
Figure 5
Figure 6
Drive
Shaft
End
Right
Side
Bottom
Port Block End
Left
See
Fig. 4
3
4
S13-42335
2
1

19
PORT BLOCK See figure 7. Position the port block (1) on a clean flat surface with the two open ports up.
THE OPPOSITE FACE MUST NOT BE SCRATCHED OR DAMAGED. Position needle
bearing (2) on tool (Figure T-5) with the marked end of the bearing against the shoulder on
the tool and press the bearing (2) into the port block.The bearing must be .010-.025" (.254-
.635 mm) below the surface.
Slip check ring (3) into the two 1.50" (38 mm) ports and align holes in the ring with the
side holes in the port wall.
Place lock washers (6) on special screws (5).Insert (5) through port wall and drilled holes
in checks (3) and thread into clamps (4).Torque to 10 ft. lbs. (13.56 Nm).
Thread socket pipe plugs (8) into port block.
Thread two check valve assemblies (7) into valve face of port block.
Place O-ring (10) on hollow hex plug (9) and thread into tapped hole in top of the port
block.
PARTS LIST FOR FIGURE 7
item description part no. qty.
1 port block 033-71296 1
2 needle bearing 230-82146 1
3 check ring 033-70502 2
4 clamp 033-70489 2
5 special screw 033-70908 2
6 no. 10 lock washer 348-10016 2
7 check valve assy. S13-40266 2
8 1/4 soc. pipe plugs 431-90404 2
9 hollow hex plug SAE-6 488-35041 1
10 O-ring 90-6290-6 691-00906 1
See figure 8 on next page. Position the pump with the unplugged hole (top drainport) in
the housing assembly at 12 o'clock position.
Install gasket (5) on the housing assembly (6).
Install the two special pins (3) in the face of the port block assembly.Apply petroleum jelly
or heavy grease to the plate (4) and position port plate over the pins (3) on the port block.
Port plate must be fully seated and indexed towards direction of rotation. (See port plate
view in figure 8.)
Slide the port block assembly and port plate over the end of the auxiliary shaft. Be cer-
tain that tubes 2, 3 and 4 shown on Fig. 4 are engaged and that the port plate (4) is still
on the pins (3).
When the pump is properly assembled, the valve mounting surface will be at the top of
the unit.
Install the four bolts (1), and torque to 225 ft.-lbs.(305 Nm). Caution: Use care to prevent
damage to the valve mounting surface while installing and torquing the two top bolts.
PARTS LIST FOR FIGURE 8
item description part no. qty.
1 hex head cap screw 5/8-11 x 9 306-40182 4
2 port block assy. See Fig. 7 1
3 port plate pins 033-49825 2
4 RH port plate 6 in3 033-71526 1
LH port plate 6 in3 033-71525 1
RH port plate 7.25 in3 033-72811 1
LH port plate 7.25 in3 033-53776 1
RH port plate 8.0 in3 033-91252 1
LH port plate 8.0 in3 033-91553 1
5 housing gasket 033-91060 1
6 housing Assy. S13-42335 1
7 mounting flange See Fig. 4 1
MOUNTING PORT
BLOCK TO HOUSING
ASSEMBLY PROCEDURES
Figure 7

20
See figure 9. Position the unit with the shaft in a horizontal position and the valve block
mounting surface turned up. Rotate the shaft until the small keyway in the auxiliary shaft
is at 12 o’clock.
If pump is being assembled for right hand rotation install dowel pin (4) in hole in port
block at the 9 o’clock position; if left hand pump, install at 3 o’clock position when view-
ing from port block end of unit.
Install side plate (1), steel side first, over dowel pin. Insert key (2) in shaft keyway. Install
the inner gear of the gerotor assembly (3b) on the shaft and over the key (2). Install the
eccentric ring (3a) on the dowel pin (4). Install the large outer gear of the gerotor assem-
bly (3b) inside the eccentric ring (3a) and over the inner gear.
Note: When changing pump rotation consult parts list for proper side plate.
Place O-rings (7) and (8) on side plate assembly.Lubricate the O-rings and slip the pres-
sure plate (9) over the O-rings on the side plate assembly. Slip the two plates over the
auxiliary shaft and position the gerotor side plate over the dowel pin (4).
Place seal ring (12) on auxiliary shaft.Position bearing (11) between the two thrust wash-
ers (10) and install around the seal ring (12). Install insert (15) over spline on shaft.
Thread holddown nut (13) on the shaft and tighten no more than 10 ft. lbs. (13.56 Nm)
max. Back off the nut (13) until second slot is aligned with pin hole in the shaft.Insert pin
(14) through nut and shaft and secure with ring (16).
Check the main shaft for smooth rotation. If not smooth, check the gerotor parts for posi-
tion and hold down nut for proper adjustment.
GEROTOR AND BARREL
HOLDDOWN
ASSEMBLY PROCEDURES
Figure 8
Figure 9
Rear View –
Width of Arcuate Ports
6 in.3is 13/32" (10,3 mm)
7.25 and 8.0 in.3is 1/2 (12,7 mm)
MOUNTING PORT
BLOCK TO HOUSING
(continued)
14
16 13 15
GEROTOR IN POSITION FOR RH ROTATION