Installation of the Giant Industries, Inc., pump is
not a complicated procedure, but there are some
basic steps common to all pumps. The following
information is to be considered as a general
outline for installation. If you have unique
requirements, please contact Giant Industries,
Inc. or your local distributor for assistance.
1. The pump should be installed flat on a base to a
maximum of a 15 degree angle of inclination to
ensure optimum lubrication.
2. The inlet to the pump should be sized for the
flow rate of the pump with no unnecessary restrictions that can cause cavitation. Teflon tape should
be used to seal all joints. If pumps are to be operated at temperatures in excess of 160oF (P56W),
190oF (P56W-HK) or 220o F (P56HT), it is important to insure a positive head to the pump to prevent
cavitation.
3. The discharge plumbing from the pump should be
properly sized to the flow rate to prevent line
pressure loss to the work area. It is essential to
provide a safety bypass valve between the pump and
the work area to protect the pump from pressure
spikes in the event of a blockage or the use of a shutoff gun.
4. Use of a dampener is necessary to minimize
pulsation at drive elements, plumbing, connections,
and other system areas. The use of a dampener with
Giant Industries, Inc. pumps is optional, although
recommended by Giant Industries, Inc. to further
reduce system pulsation. Dampeners can also
reduce the severity of pressure spikes that occur
in systems using a shut-off gun. A dampener
must be positioned downstream from the
unloader.
5. Crankshaft rotation on Giant Industries, Inc.
pumps should be made in the direction designated by the arrows on the pump crankcase.
Reverse rotation may be safely achieved by
following a few guidelines available upon
request from Giant Industries, Inc. Required
horsepower for system operation can be obtained from the charts on pages 3-4.
6. Before beginning operation of your pumping
system, remember: Check that the crankcase
and seal areas have been properly lubricated per
recommended schedules. Do not run the pump
dry for extended periods of time. Cavitation
will result in severe damage. Always remember
to check that all plumbing valves are open and
that pumped media can flow freely to the inlet of
the pump.
Finally, remember that high pressure
operation in a pump system has many
advantages. But, if it is used carelessly
and without regard to its potential hazard,
it can cause serious injury.
IMPORTANT OPERATING CONDITIONS
Failure to comply with any of these
conditions invalidates the warranty
1. Prior to initial operation, add oil to crankcase so
that the oil level is between the two lines on the oil
dipstick. DO NOT OVERFILL. Giant Recom-mended Oil. Crankcase oil should be changed after
the first 50 hours of operation, then at regular
intervals of 500 hours or less depending on operating conditions.
NOTE: Contact Giant Industries for Service School Information. Phone: (419)-531-4600.
2. Pump operation must not exceed rated
pressure, volume, or RPM. A pressure relief
device must be installed in the discharge of the
system.
3. Acids, alkalines, or abrasive fluids cannot be
pumped unless approval in writing is obtained
before operation from Giant Industries, Inc.
4. Run the pump dry approximately 10 seconds
to drain the water before exposure to freezing
temperatures.
Consult the factory for special requirements that must be met if the pump is to
operate beyond one or more of the limits specified above.
PULLEY INFORMATION
Pulley selection and pump speed are based on a 1725
RPM motor and "B" section belts. When selecting
desired GPM, allow for a ±5% tolerance on pumps
output due to variations in pulleys, belts and motors
among manufacturers.
1.Select GPM required, then select appropriate
motor and pump pulley from the same line.
2.The desired pressure is achieved by selecting the
correct nozzle size that corresponds with the pump
GPM.
P55W PULLEY SELECTION & HORSEPOWER
REQUIREMENTS
PUMP
7.75"4.00"
7.75"4.50"
7.75"5.00"
7.75"5.50"1201
7.75"6.00"1317
7.75"6.45"1420
7.75"7.751750
MOTOR
RPM GPM 500 PSI 1000 PSI 2000 PSI 2320 PSI
8512.91.02.04.04.6
9673.31.12.34.55.2
1084 3.71.32.55.15.9
4.11.42.85.66.5
4.51.53.16.27.2
4.91.73.46.77.8
6.02.14.1
HORSEPOWER INFORMATION
Horsepower ratings shown are the power requirements for the pump. Gas engine power outputs must
be approximately twice the pump power requirements shown above.
We recommend that a 1.1 service factor be specified
when selecting an electric motor as the power source.
To compute specific pump horsepower requirements,
use the following formula:
Consult the factory for special requirements that must be met if the pump is to
operate beyond one or more of the limits specified above.
PULLEY INFORMATION
Pulley selection and pump speed are based on a 1725
RPM motor and "B" section belts. When selecting
desired GPM, allow for a ±5% tolerance on pumps
output due to variations in pulleys, belts and motors
among manufacturers.
1.Select GPM required, then select appropriate
motor and pump pulley from the same line.
2.The desired pressure is achieved by selecting the
correct nozzle size that corresponds with the pump
GPM.
Horsepower ratings shown are the power requirements for the pump. Gas engine power outputs
must be approximately twice the pump power
requirements shown above.
We recommend that a 1.1 service factor be specified
when selecting an electric motor as the power source.
To compute specific pump horsepower requirements,
use the following formula:
Consult the factory for special requirements that must be met if the pump is to
operate beyond one or more of the limits specified above.
PULLEY INFORMATION
Pulley selection and pump speed are based on a 1725
RPM motor and "B" section belts. When selecting
desired GPM, allow for a ±5% tolerance on pumps
output due to variations in pulleys, belts and motors
among manufacturers.
1.Select GPM required, then select appropriate
motor and pump pulley from the same line.
2.The desired pressure is achieved by selecting the
correct nozzle size that corresponds with the pump
GPM.
HORSEPOWER INFORMATION
Horsepower ratings shown are the power requirements for the pump. Gas engine power outputs
must be approximately twice the pump power
requirements shown above.
We recommend that a 1.1 service factor be specified
when selecting an electric motor as the power source.
To compute specific pump horsepower requirements,
use the following formula:
The Pressure and/Worn packing sealsReplace packing seals
or the DeliveryBroken valve springReplace spring
DropsBelt slippageTighten or Replace belt
Worn or Damaged nozzleReplace nozzle
Fouled discharge valveClean valve assembly
Fouled inlet strainerClean strainer
Worn or Damaged hoseRepair/Replace hose
Worn or Plugged relief valve on pumpClean, Reset, and Replace worn parts
CavitationCheck suction lines on inlet of
pump for restrictions
UnloaderCheck for proper operation
Water in crankcaseHigh humidityReduce oil change interval
High CrankcaseWrong Grade of oilGiant oil is recommended
TemperatureImproper amount of oil in crankcaseAdjust oil level to proper amount
9
Page 10
P55W / P56W / P56W-HK REPAIR INSTRUCTIONS
NOTE: Always take time to lubricate all metal and nonmetal parts with a light film of oil before reassembly.
This step will ensure proper fit, at the same time protecting the pump nonmetal parts (i.e., the elastomers)
from cutting and scoring.
1. With a 22mm socket, remove
the three discharge (43) and
three inlet (41) manifold plugs.
Check o-ring (44) for wear and
replace as necessary.
4. Drain the oil from the pump.
Turn the pump over to remove
the four manifold stud nuts (46)
with a 17mm wrench.
2. Remove the discharge spring
retainer (34), valve spring (35),
and valve plate (36).
5. Tap the back of the manifold
(29) with a rubber mallet to
dislodge, and slide off the
pump.
3. Use a small slide hammer to
remove valve seats (37) from
manifold (29). Inspect valve
plates (36) and valve seats (37)
for wear. If excessive pitting is
seen, replace the worn parts.
Check valve seat o-ring (38) for
wear and replace as necessary.
Tighten manifold plugs (41 and
43) to 50 ft.-lbs.
6. From the front inlet valve ports,
remove the inlet valve assembly
(34-40) and pressure springs
(33).
7. Turn the manifold (29) over.
Using a 15mm socket, tap out
the v-sleeves, Insert v-sleeve
(31) high temperature seals
( 31A for P56W-HK &P56HT
pumps), support rings (32), and
pressure rings (30) through
back of manifold.
31
3032 33
8. Inspect and clean the manifold and pressure ring.
Reinstall the pressure ring (30) with the groved side
pointed towards the front. Insert v-sleeve (31) high
temperature seals ( 31A for P56W-HK &P56HT
pumps), support ring (32), and pressure spring (33) into
the manifold (29).
31A
(P56W-HK & P56HT)
10
Page 11
36373534
48
50
9. If pitted or worn, replace inlet valve seats (36), valve
plates (37), springs (35) and spring retainers (34).
Re-insert items 34-38 into valve adapter (39). Install
valve assembly (34-40) into manifold (29). Reinstall
manifold plugs (43) and torque plugs to 50 ft.-lbs.
49
10.The rear v-sleeve housing
(48) may be removed by
prying evenly outward
with a flat screwdriver.
After slipping housing
over ceramic plunger
(24A), inspect seals (50)
and o-ring (49) and
replace as necessary. If the
crankcase is to be disassembled, the housing
should not be replaced
until later.
24C
11.Inspect ceramic plunger (24A)
tips for wear. If necessary,
replacement of the ceramic
plungers may be accomplished
by removing the plunger bolt
assemblies (24B and 24C) with
a 13mm wrench. Ceramic
plungers should now slide off
the stainless steel plunger base
(22). Excessive resistance to
plunger removal may be
overcome by heating the
stainless steel plunger base.
This will melt any excess loctite beneath the ceramic plunger
allowing easy removal.
12.Replace copper ring (24C) onto
plunger bolt (24B). Slide
plunger bolt assembly into
ceramic plunger (24A). Apply
a light film of loc-tite to
plunger bolt threads and place
plunger assembly onto stainless
steel plunger base (22) and
tighten to 105 in.-lbs.
13.To replace plunger oil seals
(26), proceed to “Gear End
Disassembly” section below.
Otherwise, continue as described below.
11
14.Before replacing pump manifold (29), first rotate crankshaft
(18) until two outside plungers
(24A) extend evenly forward.
Next lubricate v-sleeves (50) in
the rear v-sleeve housing (48)
and slide housing over plungers. Lubricate ceramic plungers
with a light film of oil. Carefully and evenly slide manifold
over plungers and press
manifold firmly against
crankcase (1). Replace
manifold stud bolts (45),
washers (47) and nut (46) and
tighten to 35 ft.-lbs.
Page 12
Gear End Disassembly
NOTE: The manifold (29) weep seal housing (48) and spacer sleeve (26A) must be removed. See above
for directions.
15. Remove the crankcase cover screws (9). Inspect the crankcase cover o-ring (4) for wear. Replace if
necessary.
16. Inspect the dipstick (5) vent hole for signs of clogging. Clean if necessary.
17. To remove the crankshaft (18), first remove the bearing cover plates (12). Remove the key (19).
18. With a 5 mm allen wrench remove the connecting rod screws (21) and rear portion of connecting rod
assemblies (20). Push the connecting rod (20) and plunger rod (22) down as far as possible into the
crankcase housing.
19. Hold the pump rear assembly with a wooden fixture, or other suitable device, in order to secure it while
removing the crankshaft (18). Using a plastic mallet, tap the crankshaft from one side while turning it
from the other side. The turning insures that during this sequence the crankshaft does not become
wedged against the front portion of the connecting rods (20). The far side bearing (15) will remain in the
crankcase (1). When free, the crankshaft can be removed by hand. The opposite side crankshaft seal (14)
will be removed by this procedure. It is important that you turn the crankshaft (18) constantly while
tapping from the opposite end to avoid any binding. The crankshaft bearing (15) remains on the
crankshaft as it is removed. If necessary, use a bearing puller to remove the crankshaft bearing (15).
20. Remove the front portion of the connecting rods (20) and plunger base assembly (22) from the rear of the
pump by pulling straight out of the crankcase crosshead guides. Notice that the connecting rod (20)
halves are numbered or colored. Connecting rods must be positioned with their numbers or colors
on the upper left-hand side, in the same numerical sequence as when they were removed.
21. Using a dowel and a rubber mallet, tap the oil seals (26) out from the rear of crankcase (1). The area onto
which the oil seal rests should be clean and dry. Put a small drop of loc-tite on the oil seals and place into
crankcase with lips facing the rear of the pump.
22. To remove the crosshead pin (23) from the crosshead (22), the assembly should be positioned on a
wooden fixture to avoid damage to crosshead. Drive out the pin on opposite side of mark located on the
crosshead. On those pumps without mark on crosshead, drive out pin by tapping on tapered side of pin.
23. To remove the bearing (15) remaining in the crankcase (1), insert small end of Giant bearing tool and tap
with a rubber mallet until bearing and seal (14) are completely removed. The bearing can only be
removed from the inside by inserting the Giant Bearing Tool through the opposite side of the
crankcase. The crosshead guide in the crankcase should be inspected for possible damage.
24. To reassemble, place the far bearing (15) in the crankcase (1) bearing housing and with the Giant Bearing
tool as a driver, tap into the crankcase using a rubber mallet.
25. Insert the far side crankshaft oil seal (14) with the Giant Bearing Tool making sure it is firmly seated and
well oiled. Always make sure that the crankshaft seal lip does not show signs of wear and that the garter
spring is firmly in place on the seal before reinserting into the pump. Replace the bearing cover (12) and
o-ring (13) and tighten securely.
12
Page 13
26. Replace the front portion of the connecting rod (20) and plunger rod/ crosshead assembly (22) by press-fitting
the crosshead pin (23). Make sure to insert the beveled edge of the crosshead pin into crosshead. If the
crosshead has a mark, install pin from marked side. The crosshead pin (23) should not extend beyond
either side of the crosshead (22) in order to prevent damage to the crosshead bore of the crankcase (1).
27. Place each crosshead/ plunger assembly into the pump making sure that all of the parts are well oiled before
insertion into the crankcase (1). Notice that the connecting rod (20) halves are numbered or colored.
Connecting rods must be positioned with their numbers or colors on the upper left-hand side, in the
same numerical sequence as when they were removed.
28. Replace near side bearing (15) on crankshaft by using the Giant Bearing Tool and mallet to tap into place.
Take the crankshaft (18) end with the bearing (15) and insert the other end through the bearing housing and
tap with a rubber mallet until the bearing is seated.
29. When reassembling the connecting rods (20), note that the connecting rod halves are numbered or colored
and that the numbers or colors must be matched and aligned. Torque the connecting rod bolts to 125-150 in.lbs.
30. Insert the near side crankshaft oil seal (14) with the Giant Bearing Tool making sure it is firmly seated and
well oiled. Replace the bearing cover (12) and o-ring (13) and tighten securely.
See instructions above for re-installing fluid end onto the gear end.
31. Fill the P55W / P56W crankcase (1) with 14 oz. of Giant Industries’ oil and check the oil level with the
dipstick (5). Proper level is center of two lines. Reinstall the pump into your system.
13
Page 14
Preventative Maintenance Check-List & Recommended Spare Parts List
CheckDailyWeekly50hrsEvery Every Every
500 hrs 1500 hrs 3000 hrs
Oil Level/QualityX
Oil LeaksX
Water LeaksX
Belts, PulleyX
PlumbingX
Recommended Spare Parts
Oil Change (1 Gallon) p/n 1154X X
Plunger Packing Kits (1 kit/pump) X
(See page 8 for kit list)
Valve Assembly Kit (1 kit/pump) X
(See page 8 for kit list)
Oil Seal Kit (1 kit/pump) X
(See page 8 for kit list)
Pump Mounting Selection Guide
Bushings
01056 - 22 mm Tapered H Bushing
Pulley & Sheaves
01055 - 9.75” Cast Iron - 2 gr.-AB Section
01061 - 7.75” Cast Iron 1 gr. - AB Section
01062 - 7.75” Cast Iron - 2 gr. - AB Section
Rails
01034 - Steel Box Rails
(L=9.25” x W=1.18” x H=1.62”)
01075 - Plated Steel Channel Rails
Giant Industries, Inc. pumps and accessories are warranted by the manufacturer to be free from defects in
workmanship and material as follows:
1.For portable pressure washers and car wash applications, the discharge manifolds will
never fail, period. If they ever fail, we will replace them free of charge. Our other pump
parts, used in portable pressure washers and in car wash applications, are warranted
for five years from the date of shipment for all pumps used in NON-SALINE,
clean water applications.
2.One (1) year from the date of shipment for all other Giant industrial and consumer
pumps.
3.Six (6) months from the date of shipment for all rebuilt pumps.
4.Ninety (90) days from the date of shipment for all Giant accessories.
This warranty is limited to repair or replacement of pumps and accessories of which the manufacturer’s
evaluation shows were defective at the time of shipment by the manufacturer. The following items are NOT
covered or will void the warranty:
1.Defects caused by negligence or fault of the buyer or third party.
2.Normal wear and tear to standard wear parts.
3.Use of repair parts other than those manufactured or authorized by Giant.
4.Improper use of the product as a component part.
5.Changes or modifications made by the customer or third party.
6.The operation of pumps and or accessories exceeding the specifications set forth
in the Operations Manuals provided by Giant Industries, Inc.
Liability under this warranty is on all non-wear parts and limited to the replacement or repair of those products
returned freight prepaid to Giant Industries which are deemed to be defective due to workmanship or failure of
material. A Returned Goods Authorization (R.G.A.) number and completed warranty evaluation form is
required prior to the return to Giant Industries of all products under warranty consideration. Call (419)-5314600 or fax (419)-531-6836 to obtain an R.G.A. number.
Repair or replacement of defective products as provided is the sole and exclusive remedy provided hereunder
and the MANUFACTURER SHALL NOT BE LIABLE FOR FURTHER LOSS, DAMAGES, OR EXPENSES, INCLUDING INCIDENTAL AND CONSEQUENTIAL DAMAGES DIRECTLY OR INDIRECTLY ARISING FROM THE SALE OR USE OF THIS PRODUCT.
THE LIMITED WARRANTY SET FORTH HEREIN IS IN LIEU OF ALL OTHER WARRANTIES OR
REPRESENTATION, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY WARRANTIES OR MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE AND ALL SUCH
WARRANTIES ARE HEREBY DISCLAIMED AND EXCLUDED BY THE MANUFACTURER.