Operating Instructions and Parts Manual
Air/Hydraulic Bottle Jack
Models AHJ-12 and AHJ-20
WMH TOOL GROUP
2420 Vantage Drive
Elgin, Illinois 60123 Part No. M-456612
Ph.: 800-274-6848 Revision A 4/05
www.wmhtoolgroup.com Copyright © WMH Tool Group
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This manual has been prepared for the owner and operators of a JET AHJ-Series Bottle Jack. Its
purpose, aside from tool operation, is to promote safety using accepted operating and maintenance
procedures. To obtain maximum life and efficiency from your bottle jack and to aid in using it safely,
please read this manual thoroughly and follow the instructions carefully.
Warranty and Service
WMH Tool Group warrants every product it sells. If one of our tools needs service or repair, one of our
Authorized Repair Stations located throughout the United States can provide quick service or information.
In most cases, a WMH Tool Group Repair Station can assist in authorizing repair work, obtaining parts, or
perform routine or major maintenance repair on your JET product.
For the name of an Authorized Repair Station in your area, please call 1-800-274-6848, or visit our web
site at www.wmhtoolgroup.com
More Information
Remember, WMH Tool Group is consistently adding new products to the line. For complete, up-to-date
product information, check with your local WMH Tool Group distributor, or visit our web site at
www.wmhtoolgroup.com
WMH Tool Group Warranty
WMH Tool Group makes every effort to assure that its products meet high quality and durability standards
and warrants to the original retail consumer/purchaser of our products that each product be free from
defects in materials and workmanship as follows: 1 YEAR LIMITED WARRANTY ON ALL PRODUCTS
UNLESS SPECIFIED OTHERWISE. This Warranty does not apply to defects due directly or indirectly to
misuse, abuse, negligence or accidents, normal wear-and-tear, repair or alterations outside our facilities,
or to a lack of maintenance.
WMH TOOL GROUP LIMITS ALL IMPLIED WARRANTIES TO THE PERIOD SPECIFIED ABOVE,
BEGINNING FROM THE DATE THE PRODUCT WAS PURCHASED AT RETAIL. EXCEPT AS STATED
HEREIN, ANY IMPLIED WARRANTIES OR MERCHANTABILITY AND FITNESS ARE EXCLUDED.
SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG THE IMPLIED WARRANTY LASTS,
SO THE ABOVE LIMITATION MAY NOT APPLY TO YOU. IN NO EVENT SHALL WMH TOOL GROUP
BE LIABLE FOR DEATH, INJURIES TO PERSONS OR PROPERTY, OR FOR INCIDENTAL,
CONTINGENT, SPECIAL, OR CONSEQUENTIAL DAMAGES ARISING FROM THE USE OF OUR
PRODUCTS. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL
OR CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATION OR EXCLUSION MAY NOT APPLY
TO YOU.
To take advantage of this warranty, the product or part must be returned for examination, postage
prepaid, to an Authorized Repair Station designated by our office. Proof of purchase date and an
explanation of the complaint must accompany the merchandise. If our inspection discloses a defect, we
will either repair or replace the product at our discretion, or refund the purchase price if we cannot readily
and quickly provide a repair or replacement. We will return the repaired product or replacement at WMH
Tool Group’s expense, but if it is determined there is no defect, or that the defect resulted from causes
not within the scope of WMH Tool Group’s warranty, then the user must bear the cost of storing and
returning the product. This warranty gives you specific legal rights; you may also have other rights, which
vary from state to state.
WMH Tool Group sells through distributors only. Members of the WMH Tool Group reserve the right to
effect at any time, without prior notice, alterations to parts, fittings and accessory equipment, which they
may deem necessary for any reason whatsoever.
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Warning
1. Read and understand all warnings and operating instructions before attempting to use this jack.
2. Do not exceed rated capacity. Overloading can cause damage to and/or failure of the jack.
3. If jack is damaged and/or operates abnormally, remove from service until repaired.
4. Support load by appropriate means after lifting.
5. Always center load on the jack.
6. Use this jack as a lifting device only.
7. Use only on a hard, level surface capable of sustaining the load. Using the bottle jack on other than
hard, level surfaces can result in jack instability and possible loss of load.
8. Lift only on areas of the vehicle specified by the vehicle manufacturer.
9. Always replace damaged, missing or worn labels and use only genuine factory replacement parts
when replacement is necessary.
10. Only use attachments and/or adapters supplied with, or sold specifically for, the jack.
11. No alterations shall be made to this product.
12. Failure to comply with all of these warnings may result in loss of load, damage to jack, and/or
personal injury or property damage.
Specifications
Model Number.................................................................AHJ-12..................................................AHJ-20
Stock Number..................................................................456612.................................................. 456620
Rated Capacity (ton)............................................................... 12..........................................................20
Minimum Height (in.).............................................................9.65.......................................................9.65
Maximum Height (in.)..........................................................18.70.....................................................18.70
Air Pressure Required (psi)...........................................90 to 145...............................................90 to 145
Base Size (L x W)(in.) ...............................................8.27 x 6.30.............................................8.66 x 6.89
Net Weight (lbs)..................................................................26.46.....................................................30.86
Shipping Weight (lbs)..........................................................30.86.....................................................39.68
The above specifications were current at the time this manual was published, but because of our policy of
continuous improvement, WMH Tool Group reserves the right to change specifications at any time and
without prior notice, without incurring obligations.
(NOTE: Numbers in parentheses refer to item
numbers on the breakdown, page 5.)
Inspection Before Use
Prior to each use, visually inspect for leaking
hydraulic oil, damaged, loose or missing parts. If
jack becomes worn or damaged in any way, or
operates abnormally, remove it from service and
contact your nearest service center for repair.
Purging the Hydraulic System
During transit, the jack’s hydraulic system may
become filled with air, causing a spongy ram
action. The air should be purged from the
system before operating.
1. To purge air from the hydraulic system,
open the release valve (49) by turning it
counterclockwise for 2 to 3 turns.
2. Turn the jack 90° to its horizontal position.
Be sure that the air motor is underneath the
ram assembly (37).
3. Connect the air valve (29) to an air supply,
and press the lever on the air valve (29) for
20 seconds to operate the jack.
4. Close the release valve (49) by turning it
clockwise while the jack remains at its
horizontal position. If the ram assembly (37)
doesn’t extend, repeat steps 1 through 4.
Operation
Jack operation is controlled either manually or
by external air pressure. To operate manually,
insert the handle (61) into the handle socket
(60). To operate by air pressure, connect the air
valve (29) to an external air pressure source.
Clean the air connections and lubricate air motor
prior to assembly.
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To raise the jack, turn the release valve (49)
clockwise until it is tight, and either manually
pump with the handle, or press the lever on the
air valve (29) if connected to an air supply.
To lower the jack, turn the release valve (49)
counterclockwise slightly and very slowly. Do not
turn valve too quickly or more than twice.
When lowering the jack, do
not turn release valve too quickly or turn the
valve more than twice. This can cause the
load to descend too rapidly creating a
dangerous situation.
Maintenance
Maintain oil at full level. To check the oil,
proceed as follows:
1. With the jack in an upright position and the
ram completely retracted, open the release
valve (49) by turning it counterclockwise.
2. Unscrew and remove the filler plug (31). The
oil level should be just up to the hole.
3. If necessary, fill with clean hydraulic jack oil.
4. Re-install the filler plug (31).
With the release valve (49) open, manually
pump the handle six times. This will keep
internal components lubricated.
To prevent corrosion, occasionally lubricate the
handle socket pivot point (60), release valve
screw thread (49), and air valve (29), with a light
coat of oil.
Troubleshooting the AHJ Bottle Jack
Trouble Probable Cause Remedy
Air in hydraulic system.
Bleed air by opening release valve (49).
Pump for 20 seconds.
Viscosity of oil is too high. Change to a lower viscosity oil.
Erratic Action.
Internal leakage in ram (37).
Replace worn packing. Look for excessive
contamination or wear.
Release valve (49) is open. Close release valve (49).
Low or no oil in reservoir.
Fill reservoir with oil and bleed air from
system.
Air locked in system.
Bleed air by opening release valve (49).
Pump for 20 seconds.
Ram does not advance.
Load is above capacity. Use correct equipment rated for that load.
Low oil level in reservoir.
Fill reservoir with oil and bleed air from
system.
Ram does not extend or
only partially.
Pump plunger (57) is binding.
Look for dirt, gummy deposits, leaks,
misalignment, worn parts, or defective
packing.
Low air pressure. Adjust air pressure to 90 to 145 psi.
Ram advances slowly.
Leaking seals. Replace seals.
Release valve (49) is open. Close release valve (49).
Ram advances but does
not hold load.
Ram seals are leaking. Replace seals.
Release valve (49) is closed. Open release valve (49).
Reservoir is too full. Drain oil to correct level.
Ram will not retract, or
retracts slowly.
Ram damaged internally.
Take jack to authorized service center for
repair.
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AHJ-12 and AHJ-20 Bottle Jacks
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Replacement Parts
Replacement parts are listed on the following pages. To order parts or reach our service department, call
1-800-274-6848 between 7:30 a.m. and 6:00 p.m. (CST), Monday through Friday. Having the Model
Number and Serial Number of your product available when you call will allow us to serve you quickly and
accurately.
Parts List: AHJ-12 Bottle Jack
Index No. Part No. Description Size Qty
1...............AHJ12-1.................. Pump Cylinder............................................. .........................................1
2...............AHJ12-2.................. Y-Seal*........................................................5.8x12x5.2mm..................1
3...............AHJ12-3.................. Nylon Gasket*..............................................5.8x12x1.25mm................1
4...............AHJ12-4.................. Copper Washer ........................................... .........................................1
5...............AHJ12-5.................. Nut .............................................................. .........................................1
6...............AHJ12-6.................. O-Ring.........................................................18x2.65mm.......................1
7...............TS-1503051............ Socket Head Cap Screw..............................M6x20...............................8
8...............AHJ12-8.................. Base Cover.................................................. .........................................1
9...............SB-3........................Steel Ball.....................................................Ø 3mm..............................4
10.............AHJ12-10................ Air Motor Housing........................................ .........................................1
11.............AHJ12-11................ Nut .............................................................. .........................................1
12.............AHJ12-12................ Spring.......................................................... .........................................1
13.............AHJ12-13................ Washer........................................................ .........................................1
14.............AHJ12-14................ Air Pump Plunger......................................... .........................................1
15.............AHJ12-15................ Air Piston Base............................................ .........................................1
16.............AHJ12-16................ O-Ring.........................................................20.3x2.65mm....................2
17.............AHJ12-17................ Air Shuttle Valve.......................................... .........................................1
18.............AHJ12-18................ O-Ring.........................................................43x3.55mm.......................2
19.............AHJ12-19................ Air Piston..................................................... .........................................1
20.............TS-1502021............ Socket Head Cap Screw..............................M5x10...............................3
21.............AHJ12-21................ Shuttle Valve Seal ....................................... .........................................1
22.............AHJ12-22................ O-Ring.........................................................57x5.3mm.........................2
23.............AHJ12-23................ O-Ring.........................................................67x2.4mm.........................1
24.............AHJ12-24................ Top Cover.................................................... .........................................1
25.............AHJ12-25................ Snap Ring....................................................Ø 14mm............................1
26.............AHJ12-26................ O-Ring.........................................................11.5x1.5mm......................2
27.............AHJ12-27................ Coupler........................................................ .........................................1
28.............AHJ12-28................ Air Hose Assembly ...................................... .........................................1
29.............AHJ12-29................ Air Valve Assembly...................................... .........................................1
30.............AHJ12-30................ Oil Tank Assembly....................................... .........................................1
31.............AHJ12-31................ Oil Filler Plug............................................... .........................................1
32.............AHJ12-32................ Snap Ring....................................................Ø 36mm............................1
33.............AHJ12-33................ O-Ring Retainer........................................... .........................................1
34.............AHJ12-34................ O-Ring* .......................................................36x4.6mm.........................1
35.............AHJ12-35................ Seal Washer*............................................... .........................................1
36.............AHJ12-36................ Piston Ring.................................................. .........................................1
37.............AHJ12-37................ Ram Assembly ............................................ .........................................1
38.............AHJ12-38................ Bushing....................................................... .........................................2
39.............AHJ12-39................ O-Ring* .......................................................43x3.55mm.......................1
40.............AHJ12-40................ Snap Ring.................................................... .........................................1
41.............SB-4........................Steel Ball.....................................................Ø 4mm..............................1
42.............AHJ12-42................ Safety Valve Ball Seat ................................. .........................................1
43.............AHJ12-43................ Safety Valve Spring..................................... .........................................1
44.............AHJ12-44................ Safety Valve Adjusting Screw...................... .........................................1
45.............AHJ12-45................ O-Ring* .......................................................7.5x2.65mm......................2
46.............AHJ12-46................ Screw.......................................................... .........................................1
47.............AHJ12-47................ Copper Washer ........................................... .........................................4
48.............AHJ12-48................ Valve Block Assembly.................................. .........................................2
49.............AHJ12-49................ Release Valve Assembly ............................. .........................................1
50.............SB-6........................Steel Ball.....................................................Ø 6mm..............................1
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51.............AHJ12-51................ Link Pin ....................................................... .........................................2
52.............AHJ12-52................ Pin............................................................... .........................................3
53.............AHJ12-53................ Pump Cylinder............................................. .........................................1
54.............AHJ12-54................ O-Ring* .......................................................7x3mm..............................1
55.............AHJ12-55................ Nylon Gasket*..............................................7x12x1.5mm.....................1
56.............AHJ12-56................ Dustproof Ring.............................................12.5x18.5x6mm................1
57.............AHJ12-57................ Pump Plunger.............................................. .........................................1
58.............AHJ12-58................ Pump Plunger Pin........................................ .........................................1
59.............AHJ12-59................ Link ............................................................. .........................................1
60.............AHJ12-60................ Handle Socket............................................. .........................................1
61.............AHJ12-61................ Front Handle................................................ .........................................1
62.............AHJ12-62................ Rear Handle................................................ .........................................1
63.............TS-1540031............ Hex Nut.......................................................M5....................................1
64.............TS-2361051............ Lock Washer................................................M5....................................1
65.............TS-1550031............ Flat Washer.................................................M5....................................1
66.............TS-2285302............ Phillips Pan Head Machine Screw................M5x30...............................1
67.............AHJ12-67................ Hex Nut (Thin).............................................M10..................................2
68.............AHJ12-68................ Return Spring.............................................. .........................................2
69.............AHJ12-69................ Screw ......................................................... .........................................2
70.............AHJ12-70................ Spring Lid.................................................... .........................................1
.................AHJ12-RK............... Repair Kit for AHJ-12 *................................. ...........................................
Items marked with an asterisk (*) are included in the Repair Kit.
Parts List: AHJ-20 Bottle Jack
Index No. Part No. Description Size Qty
1...............AHJ12-1.................. Pump Cylinder............................................. .........................................1
2...............AHJ12-2.................. Y-Seal*........................................................5.8x12x5.2mm..................1
3...............AHJ12-3.................. Nylon Gasket*..............................................5.8x12x1.25mm................1
4...............AHJ12-4.................. Copper Washer ........................................... .........................................1
5...............AHJ12-5.................. Nut .............................................................. .........................................1
6...............AHJ12-6.................. O-Ring.........................................................18x2.65mm.......................1
7...............TS-1503051............ Socket Head Cap Screw..............................M6x20...............................8
8...............AHJ12-8.................. Base Cover.................................................. .........................................1
9...............SB-3........................Steel Ball.....................................................
Ø3mm...............................4
10.............AHJ12-10................ Air Motor Housing........................................ .........................................1
11.............AHJ12-11................ Nut .............................................................. .........................................1
12.............AHJ12-12................ Spring.......................................................... .........................................1
13.............AHJ12-13................ Washer........................................................ .........................................1
14.............AHJ12-14................ Air Pump Plunger......................................... .........................................1
15.............AHJ12-15................ Air Piston Base............................................ .........................................1
16.............AHJ12-16................ O-Ring.........................................................20.3x2.65mm....................2
17.............AHJ12-17................ Air Shuttle Valve.......................................... .........................................1
18.............AHJ12-18................ O-Ring.........................................................43x3.55mm.......................2
19.............AHJ12-19................ Air Piston..................................................... .........................................1
20.............TS-1502021............ Socket Head Cap Screw..............................M5x10...............................3
21.............AHJ12-21................ Shuttle Valve Seal ....................................... .........................................1
22.............AHJ12-22................ O-Ring.........................................................57x5.3mm.........................2
23.............AHJ12-23................ O-Ring.........................................................67x2.4mm.........................1
24.............AHJ12-24................ Top Cover.................................................... .........................................1
25.............AHJ12-25................ Snap Ring....................................................
Ø14mm.............................1
26.............AHJ12-26................ O-Ring.........................................................11.5x1.5mm......................2
27.............AHJ12-27................ Coupler........................................................ .........................................1
28.............AHJ12-28................ Air Hose Assembly ...................................... .........................................1
29.............AHJ12-29................ Air Valve Assembly...................................... .........................................1
30.............AHJ20-30................ Oil Tank Assembly....................................... .........................................1
31.............AHJ20-31................ Oil Filler Plug............................................... .........................................1
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32.............AHJ20-32................ Snap Ring....................................................Ø40mm.............................1
33.............AHJ20-33................ O-Ring Retainer........................................... .........................................1
34.............AHJ20-34................ O-Ring* .......................................................46.8x4.6mm......................1
35.............AHJ20-35................ Seal Washer*............................................... .........................................1
36.............AHJ20-36................ Piston Ring.................................................. .........................................1
37.............AHJ20-37................ Ram Assembly ............................................ .........................................1
38.............AHJ20-38................ Bushing....................................................... .........................................2
39.............AHJ20-39................ O-Ring* .......................................................53x4.6mm.........................1
40.............AHJ20-40................ Snap Ring.................................................... .........................................1
41.............SB-4........................Steel Ball.....................................................
Ø4mm...............................1
42.............AHJ12-42................ Safety Valve Ball Seat ................................. .........................................1
43.............AHJ12-43................ Safety Valve Spring..................................... .........................................1
44.............AHJ12-44................ Safety Valve Adjusting Screw...................... .........................................1
45.............AHJ12-45................ O-Ring* .......................................................7.5x2.65mm......................2
46.............AHJ12-46................ Screw.......................................................... .........................................1
47.............AHJ12-47................ Copper Washer ........................................... .........................................4
48.............AHJ12-48................ Valve Block Assembly.................................. .........................................2
49.............AHJ12-49................ Release Assembly....................................... .........................................1
50.............SB-6........................Steel Ball.....................................................
Ø6mm...............................1
51.............AHJ12-51................ Link Pin ....................................................... .........................................2
52.............AHJ12-52................ Pin............................................................... .........................................3
53.............AHJ12-53................ Pump Cylinder............................................. .........................................1
54.............AHJ12-54................ O-Ring* .......................................................7x3mm..............................1
55.............AHJ12-55................ Nylon Gasket*..............................................7x12x1.5mm.....................1
56.............AHJ12-56................ Dustproof Ring.............................................12.5x18.5x6mm................1
57.............AHJ12-57................ Pump Plunger.............................................. .........................................1
58.............AHJ12-58................ Pump Plunger Pin........................................ .........................................1
59.............AHJ12-59................ Link ............................................................. .........................................1
60.............AHJ12-60................ Handle Socket............................................. .........................................1
61.............AHJ12-61................ Front Handle................................................ .........................................1
62.............AHJ12-62................ Rear Handle................................................ .........................................1
63.............TS-1540031............ Hex Nut.......................................................M5....................................1
64.............TS-2361051............ Lock Washer................................................M5....................................1
65.............TS-1550031............ Flat Washer.................................................M5....................................1
66.............TS-2285302............ Phillips Pan Head Machine Screw................M5x30...............................1
67.............AHJ20-67................ Hex Nut (Thin).............................................M10..................................2
68.............AHJ20-68................ Return Spring.............................................. .........................................2
69.............AHJ20-69................ Screw.......................................................... .........................................2
70.............AHJ20-70................ Spring Lid.................................................... .........................................1
.................AHJ20-RK............... Repair Kit for AHJ-20 *................................. ...........................................
Items marked with an asterisk (*) are included in the Repair Kit.
WMH Tool Group
2420 Vantage Drive
Elgin, Illinois 60123
Phone: 800-274-6848
www.wmhtoolgroup.com
