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12 VOLT DIESEL TRANSFER PUMP
item 66784
tM
ITEM 66784
UPC 193175542670
DO NOT REMOVE
TM
Serial:
24e
12 VDC / 13.5 A / 30 Minutes Per Hour Duty Cycle
Owner’s Manual & Safety Instructions
Save This Manual Keep this manual for the safety warnings and precautions, assembly,
operating, inspection, maintenance and cleaning procedures. Write the product’s Date Code in the back of
the manual near the assembly diagram (or month and year of purchase if product has no number). Keep
this manual and the receipt in a safe and dry place for future reference. 26j
When unpacking, make sure that the product is intact and
undamaged. If any parts are missing or broken, please
visit harborfreight.com/customer-support/contact-us
as soon as possible.
Copyright
©
2024 by Harbor Freight Tools
®
. All rights reserved.
No portion of this manual or any artwork contained herein may be reproduced in
any shape or form without the express written consent of Harbor Freight Tools.
Diagrams within this manual may not be drawn proportionally. Due to continuing
improvements, actual product may differ slightly from the product described herein.
Tools required for assembly and service may not be included.
Read this material before using this product.
Failure to do so can result in serious injury.
SAVE THIS MANUAL.
Page 2
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Item 66784
SaFety OperatiOn MaintenanceSetup
table of contents
Safety ......................................................... 2
Specifications ............................................. 6
Setup .......................................................... 7
Operation .................................................... 8
Maintenance ............................................... 9
Component List and Diagram .................... 10
Warranty .................................................... 12
tM
WarninG SyMBOLS anD DeFinitiOnS
This is the safety alert symbol. It is used to alert you to potential
personal injury hazards. Obey all safety messages that
follow this symbol to avoid possible injury or death.
Indicates a hazardous situation which, if not avoided,
will result in death or serious injury.
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
Indicates a hazardous situation which, if not avoided,
could result in minor or moderate injury.
Addresses practices not related to personal injury.
iMpOrtant SaFety inFOrMatiOn
General Safety Warnings
read all safety warnings and all instructions.
Failure to follow the warnings and instructions may result in electric shock, fire and/or serious injury.
Save all warnings and instructions for future reference.
The warnings, precautions, and instructions discussed in this instruction manual cannot cover all possible
conditions and situations that may occur. It must be understood by the operator that common sense and
caution are factors which cannot be built into this product, but must be supplied by the operator.
Work area Safety
1. Keep work area clean and well lit. Cluttered
or dark areas increase the risks of electric
shock, fire, and injury to persons.
2. Do not operate pumps in explosive
atmospheres, such as in the presence of
flammable liquids, gases or dust. Pumps create
sparks which may ignite the dust or fumes.
3. Keep bystanders, children, and visitors away
while operating the pump. Distractions are
able to result in the loss of control of the pump.
Page 3
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Item 66784
SaFetyOperatiOnMaintenance Setup
electrical Safety
1. Do not expose pumps to rain or wet
conditions. Water entering a pump will
increase the risk of electric shock.
2. Do not abuse the power cables. never use
the cables for carrying or pulling the pump.
Keep cables away from heat, oil, sharp edges
or moving parts. Damaged or entangled
cables increase the risk of electric shock.
personal Safety
1. Stay alert, watch what you are doing and use
common sense when operating a pump. Do not
use a pump while you are tired or under the
influence of drugs, alcohol or medication.
A moment of inattention while operating pumps
may result in serious personal injury.
2. prevent unintentional starting. Ensure
the switch is in the off-position before
connecting to the power supply.
3. Do not overreach. Keep proper footing
and balance at all times. Proper footing
and balance enables better control of
the pump in unexpected situations.
4. use safety equipment. A dust mask, non-
skid safety shoes and a hard hat must be
used for the applicable conditions.
5. Dress properly. Do not wear loose clothing or
jewelry. Keep your hair, clothing and gloves
away from moving parts. Loose clothes, jewelry
or long hair can be caught in moving parts.
6. Wear ANSI-approved safety goggles
during setup and use.
pump use and care
1. Do not force the pump. use the correct
pump for your application. The correct
pump will do the job better and safer at
the rate for which it was designed.
2. Do not use the pump if the switch does not turn
it on and off. Any pump that cannot be controlled
with the switch is dangerous and must be repaired.
3. Disconnect the cables from the power
supply before making any adjustments,
changing accessories, or storing pumps.
Such preventive safety measures reduce
the risk of starting the pump accidentally.
4. Store idle pumps out of the reach of children and
do not allow persons unfamiliar with the pump or
these instructions to operate the pump. Pumps
are dangerous in the hands of untrained users.
5. Maintain pumps. check for misalignment or
binding of moving parts, breakage of parts
and any other condition that may affect the
pump’s operation. if damaged, have the
pump repaired before use. Many accidents
are caused by poorly maintained pumps.
6. use the pump, accessories and pump bits
etc. in accordance with these instructions,
taking into account the working conditions
and the work to be performed. Use of the
pump for operations different from those
intended could result in a hazardous situation.
Battery precautions
under abusive conditions, liquid may be ejected from the battery. avoid contact. if
contact accidentally occurs, flush with water. if liquid contacts eyes, additionally
seek medical help. Liquid ejected from the battery may cause irritation or burns.
Service
pump service must be performed only by qualified repair personnel, using only identical replacement parts.
This will ensure that the safety of the pump is maintained.
Page 4
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Item 66784
SaFety OperatiOn MaintenanceSetup
Specific Safety instructions
1. this pump is designed for use with diesel fuel or
kerosene only. not for use with fluids that have a
flash point below 100° F (i.e., gasoline, alcohol).
2. never smoke near the pump or use
the pump near an open flame.
3. Do not use for fluid transfer into or from aircraft.
4. this product is not designed for
use with medical products, water, or
fluids for human consumption.
5. anchor the barrel or tank
(not included) to prevent tipping.
6. Do not use while on a motorized vehicle
while the engine is running.
7. Avoid unintentional starting. Prepare to
begin work before turning on the Pump.
8. When using a handheld pump, maintain
a firm grip on the pump with both
hands to resist starting torque.
9. Do not leave the Pump unattended when
it is connected to a power supply. Turn
off the pump, and disconnect it from
its power supply before leaving.
10. Do not operate switch with wet hands.
11. Do not keep bypass valve open
more than 2 minutes.
12. This product is not a toy. Keep it
out of reach of children.
13. Stop using Pump if fuel leakage is detected.
14. Maintain labels and nameplates on the
Pump. These carry important safety
information. If unreadable or missing, contact
Harbor Freight Tools for a replacement.
15. People with pacemakers should consult their
physician(s) before use. Electromagnetic fields in
close proximity to heart pacemaker could cause
pacemaker interference or pacemaker failure. In
addition, people with pacemakers should:
• Avoid operating alone.
• Do not use with power switch locked on.
• Properly maintain and inspect
to avoid electrical shock.
16. The warnings, precautions, and instructions
discussed in this instruction manual cannot
cover all possible conditions and situations
that may occur. It must be understood by the
operator that common sense and caution are
factors which cannot be built into this product,
but must be supplied by the operator.
SaVe tHeSe inStructiOnS.
Page 5
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Item 66784
SaFetyOperatiOnMaintenance Setup
Symbology
Double Insulated
V
Volts
~
Alternating Current
a
Amperes
n
0
xxxx/min.
No Load Revolutions per Minute (RPM)
WARNING marking concerning Risk
of Eye Injury. Wear ANSI-approved
safety goggles with side shields.
Read the manual before
set-up and/or use.
WARNING marking
concerning Risk of Fire.
Do not cover ventilation ducts.
Keep flammable objects away.
WARNING marking concerning
Risk of Electric Shock.
Properly connect power cord
to appropriate outlet.
Page 6
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Item 66784
SaFety OperatiOn MaintenanceSetup
Specifications
Product
Applications
Only use with diesel fuel or kerosene.
Do not use with gasoline, alcohol, water, corrosive chemicals,
solvents, or liquids that have a flash point below 100° F.
Electrical Input 12VDC / 13.5A
Fuse 25A (included)
Motor
30 Minute Duty Cycle*
2800 RPM
Pump
Self-Priming, Volumetric, Rotating Vane, with Bypass Valve
Inlet / Outlet: 3/4″ Female NPT
Lift: 6.6 Feet
Flow Rate: 10 GPM
Operating Conditions
-4° – 140° F
up to 90% Relative Humidity
Hose Size
3/4″ I.D., 1-1/4″ O.D.,
13′ Long
Thermal Overload
Protection
Yes
*Duty cycle (Duration of use)
30 Minute Duty cycle
30 minutes pumping
followed by
at least 30 minutes of rest
avoid damage to the pump by not pumping for
more than the prescribed duty cycle time. The Duty
Cycle defines the number of minutes, within a one hour
period, during which a given pump can pump without
overheating. For example, this Pump with a 30 minute
duty cycle must be allowed to rest for at least 30 minutes
after every 30 minutes of use. Failure to carefully
observe duty cycle limitations can easily over-stress
a pump contributing to premature pump failure.
This pump has an internal thermal protection
system to help prevent this sort of over-stress.
When the unit overheats, it automatically shuts
down, then it automatically begins pumping
again after cooling off. When the pump can be
used again, use shorter pumping periods and
longer rest periods to prevent needless wear.
tM
Page 7
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Item 66784
SaFetyOperatiOnMaintenance Setup
Setup - Before use:
read the entire iMpOrtant SaFety inFOrMatiOn section at the beginning of this
manual including all text under subheadings therein before set up or use of this product.
tO preVent SeriOuS inJury FrOM acciDentaL OperatiOn:
Disconnect the pump from its power supply before assembly/installation.
note: For additional information regarding the parts listed in the following pages,
refer to Component List and Diagram on page 10.
assembly
note: Thread seal tape mentioned hereafter
is not supplied with this pump.
1. Cut the supplied hose, into two lengths, keeping
in mind that the suction end should be long
enough to reach within one inch of the supply
tank bottom and at the same time to be long
enough so that the Pump could be located at
a point away from the supply tank opening.
nOZZLe (12)
HOSe
cOnnectOr (8)
HOSe
cLaMp (10)
HOSe
cLaMp (10)
HOSe
cOnnectOr (11)
HOSe (27)
puMp
OutLet
2. Apply pipe thread seal tape to the threads
of one 3/4″ Hose Connector (8) and
screw it firmly into the Pump outlet.
3. Apply pipe thread seal tape to the threads
of the 1″ Hose Connector (11) and
screw it firmly into the Nozzle (12).
note: The included Hose (27) can be cut to
provide an inlet and outlet hose, or another hose
of the same size can be purchased as needed.
any hose used with this product must be
designed for use with the liquid being pumped.
4. Slide two Hose Clamps (10) onto the discharge
Hose (27). Twist each end of the hose over
the two barbed fittings and push forward
until the hose ends presses firmly over the
O-rings and against the fitting shoulder.
5. Slide the Hose Clamps to within 3/8″ of
the fitting shoulder and tighten the screws,
securing the hose onto the fittings.
6. Apply pipe thread seal tape to the threads
of one 3/4″ Hose Connector (8) and
screw it firmly into the Pump inlet.
3/4″ HOSE
cOnnectOr (11)
HOSe (27)
Strainer (33)
HOSe
cLaMp (10)
HOSe
cLaMp (10)
puMp
inLet
7. Slide two Hose Clamps (10) onto the inlet Hose
(27). Twist one end of the hose over the pump
inlet barbed fitting and the other end over the
barbed fitting on the strainer. Push the hose
forward until the hose ends presses firmly over
the O-rings and against the fitting shoulders.
8. Slide the Hose Clamps to within 3/8″ of
the fitting shoulder and tighten the screws,
securing the hose onto the fittings.
Page 8
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Item 66784
SaFety OperatiOn MaintenanceSetup
Operating instructions
read the entire iMpOrtant SaFety inFOrMatiOn section at the beginning of this manual
including all text under subheadings therein before set up or use of this product.
inspect pump before use, looking for damaged, loose, and missing parts. if
any problems are found, do not use pump until repaired.
pump Set up
tO preVent SeriOuS inJury FrOM acciDentaL OperatiOn:
Disconnect the pump from its 12 volt power source before performing
any inspection, maintenance, or cleaning procedures.
1. Designate a work area that is clean and well-lit.
The work area must not allow access by children
or pets to prevent distraction or injury.
2. Route the Power Cables along a safe route to reach
the work area without creating a tripping hazard
or exposing the cables to possible damage. The
cables must reach the work area with enough extra
length to allow free movement while working.
3. There must not be hazardous objects, such
as utility lines or foreign objects, nearby that
will present a hazard while working.
4. Have rags nearby to clean up any fuel spills.
5. Have multiple fully charged ABC fire
extinguishers nearby in case of fire.
6. Ensure destination tank has sufficient
capacity before transfer.
General Operating instructions
1. Connect the Cables with Clamps to a 12 volt power
supply (such as a battery, not included). Connect
the RED Clamp to the Positive (+) terminal and
the BLACK Clamp to the Negative (-) terminal.
2. Insert the Nozzle into the destination tank.
3. Insert the Hose with its Strainer into the fuel supply
tank. Immerse the Strainer in the fuel fully.
4. Press the Power Switch to start the Pump.
note: Use Power Switch to start/stop Pump; do not
use power supply connection for this purpose.
5. Squeeze trigger of the Nozzle to
discharge fuel into the destination tank.
Hold the Nozzle firmly during the fuel transfer.
6. To reduce hand fatigue during extended pumping,
lock the Trigger in one of the two positions by lifting
and positioning the spring loaded trigger lock into
one of the two recessed steps under the trigger.
Ease back on trigger to lock it in place.
To stop pumping, pull slightly on the
trigger to release the lock.
7. When the fuel has been transferred, release
pressure on the Nozzle Trigger. When fuel stops
flowing, turn off the Pump. Do not run pump dry.
8. Disconnect the Cables with Clamps black first,
then red, from the 12 volt power supply.
9. Remove the Nozzle from the destination
tank and place in a secure location.
10. Remove the Hose with its Strainer from
the fuel supply tank, allowing fuel to drain
out of the Hose before removing it.
11. Cap both supply and the destination
tanks to prevent fuel spills.
12. Clean and dry all exterior parts of the Pump
Body, Hose, Nozzle, and Cables with Clamps.
13. Store the Pump indoors and out of reach of
children and other unauthorized persons.
Page 9
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Item 66784
SaFetyOperatiOnMaintenance Setup
Maintenance and Servicing
procedures not specifically explained in this manual must
be performed only by a qualified technician.
tO preVent SeriOuS inJury FrOM acciDentaL OperatiOn:
Disconnect the pump from its 12 volt power source before performing
any inspection, maintenance, or cleaning procedures.
tO preVent SeriOuS inJury FrOM puMp FaiLure:
Do not use damaged equipment. if abnormal noise, vibration, or leaking
air occurs, have the problem corrected before further use.
cleaning, Maintenance, and Lubrication
1. BeFOre eacH uSe, inspect the general
condition of the pump. Check for:
• loose hardware,
• misalignment or binding of moving parts,
• damaged cord/electrical wiring,
• cracked or broken parts, and
• any other condition that may
affect its safe operation.
2. aFter uSe, wipe external surfaces
of the pump with clean cloth.
3. tO repLace tHe FuSe:
a. Disconnect the Cables from
the 12V power source.
b. Open the Fuse Holder on the Cable.
c. Remove the Fuse by pulling it straight out of
the Fuse Holder. Then press in a new Fuse
of the same type, size, and rating (25A).
d. Close the Fuse Holder on the Cable.
troubleshooting
problem possible causes Likely Solutions
Pump will not start. 1. Battery is dead or discharged.
2. Clamps are not properly
connected.
3. Fuse burned out.
1. Check battery power.
2. Make sure clamps are securely connected.
3. Replace with new fuse.
Pump will not
operate or pumps
fuel in wrong
direction.
Clamps are connected
in wrong polarity.
Reverse clamps.
(Red clamp on positive (+) terminal.
Black clamp on negative (–) terminal).
Poor fuel transfer. 1. Intake hose is not
submerged in fuel or supply
tank is low or empty.
2. Clogged Strainer.
3. Kinked hoses.
4. Hoses are leaking.
5. Hoses or handle is clogged.
1. Check intake hose and supply tank.
2. Wash/replace Strainer.
3. Straighten Hose.
4. Check hoses for leaks and repair or replace.
5. Check and clean hoses and handle.
Follow all safety precautions whenever diagnosing or servicing the tool.
Disconnect power supply before service.
Page 10
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Item 66784
SaFety OperatiOn MaintenanceSetup
component List and Diagram
pLeaSe reaD tHe FOLLOWinG careFuLLy
THE MANUFACTURER AND/OR DISTRIBUTOR HAS PROVIDED THE COMPONENT LIST AND ASSEMBLY
DIAGRAM IN THIS MANUAL AS A REFERENCE TOOL ONLY. NEITHER THE MANUFACTURER OR
DISTRIBUTOR MAKES ANY REPRESENTATION OR WARRANTY OF ANY KIND TO THE BUYER THAT HE
OR SHE IS QUALIFIED TO MAKE ANY REPAIRS TO THE PRODUCT, OR THAT HE OR SHE IS QUALIFIED
TO REPLACE ANY PARTS OF THE PRODUCT. IN FACT, THE MANUFACTURER AND/OR DISTRIBUTOR
EXPRESSLY STATES THAT ALL REPAIRS AND PARTS REPLACEMENTS SHOULD BE UNDERTAKEN BY
CERTIFIED AND LICENSED TECHNICIANS, AND NOT BY THE BUYER. THE BUYER ASSUMES ALL RISK
AND LIABILITY ARISING OUT OF HIS OR HER REPAIRS TO THE ORIGINAL PRODUCT OR REPLACEMENT
PARTS THERETO, OR ARISING OUT OF HIS OR HER INSTALLATION OF REPLACEMENT PARTS THERETO.
component List
part Description Qty
1 Screw (M5x10) 8
2 Front Cover 1
3 O-Ring 1
4 Rotor 1
5 Blade 5
6 Pump Body 1
7 Bypass Valve 1
8 3/4″ Male Hose Connector 2
9 Handle 1
10 Hose Clamp 4
11 1″ Hose Connector 1
12 Nozzle 1
13 Fuse (25A) 1
15 Power Switch 1
16 Cables with Clamps and Fuse Holder 1
part Description Qty
17 Terminal Board 1
18 Screw (M4x15) 2
19 Compression Nut 1
20 Tapered Ring 1
21 Nut (M5) 2
22 Terminal 2
23 12VDC Motor 1
24 Bearing 2
25 Spring Collar 1
26 Seal 1
27 Hose 1
30 Bypass Spring 1
31 Base 1
32 Key 1
33 Strainer 1
record product’s Date code Here:
note: if product has no Date code, record month and year of purchase instead.
note: Some parts are listed and shown for illustration purposes only, and are not
available individually as replacement parts. Reference UPC 193175542670.
The component list and assembly diagram are shown for reference only.
To view all currently available replacement parts, please visit harborfreight.com/parts
Page 11
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Item 66784
SaFetyOperatiOnMaintenance Setup
assembly Diagram
tM
26677 agoura road • calabasas, ca 91302 • 1-800-444-3353
Limited 90 Day Warranty
Harbor Freight Tools Co. makes every effort to assure that its products meet high quality and durability standards,
and warrants to the original purchaser that this product is free from defects in materials and workmanship for the
period of 90 days from the date of purchase. This warranty does not apply to damage due directly or indirectly,
to misuse, abuse, negligence or accidents, repairs or alterations outside our facilities, criminal activity, improper
installation, normal wear and tear, or to lack of maintenance. We shall in no event be liable for death, injuries
to persons or property, or for incidental, contingent, special or consequential damages arising from the use of
our product. Some states do not allow the exclusion or limitation of incidental or consequential damages, so the
above limitation of exclusion may not apply to you. THIS WARRANTY IS EXPRESSLY IN LIEU OF ALL OTHER
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS.
To take advantage of this warranty, the product or part must be returned to us with transportation charges
prepaid. Proof of purchase date and an explanation of the complaint must accompany the merchandise.
If our inspection verifies the defect, we will either repair or replace the product at our election or we may
elect to refund the purchase price if we cannot readily and quickly provide you with a replacement. We will
return repaired products at our expense, but if we determine there is no defect, or that the defect resulted
from causes not within the scope of our warranty, then you must bear the cost of returning the product.
This warranty gives you specific legal rights and you may also have other rights which vary from state to state.
