Guide to

Maintenance,

Troubleshooting, and Repair

N4950, N5450, N6450,

N4300*, N5300*, N6300*

N4950TS, N5450CS

METAL HANDLE

HAND CUPS

* Some details may not apply to hand

cups with ABS plunger assemblies.

THE ORIGINAL

& TRUSTED NAME

IN VACUUM LIFTING

EQUIPMENT

General Maintenance

For maximum reliability, INSPECT THE HAND CUP REGULARLY: Make sure the air filter is in place; if not, discontinue use until the filter is replaced. Examine the plunger assembly and handle for dents, cracks or other damage. Examine the face of the vacuum pad for excessive glaze (a polished, glossy appearance) and for cuts or roughness on the sealing edges. Periodically test the cup for excessive leakage, sluggishness in plunger action or radical changes in the number of strokes needed to keep the red line hidden. If the cup does not function normally, review the

Troubleshooting Guide (overleaf) to determine what corrective action is needed.

To CLEAN THE VACUUM PAD, remove the air filter from the pad face. Use a clean sponge or lint-free cloth to apply soapy water or another mild cleanser to the cup face. Never use

solvents or rubber conditioners as a cleaning agent (see WARNINGS). To prevent liquid from contaminating the pump during cleaning, hold the cup face-down or cover the suction inlet in the filter recess. For 8" [20 cm] pads, be careful not to dampen the felt strip at the pad’s edge. Wipe all residue from the pad face and allow the cup to dry. Then reinstall the air filter.

908 West Main - P.O. Box 368

Laurel, Montana 59044 U.S.A.

406.628.8231 (phone)

406.628.8354 (fax)

800.548.7341

www.WPG.com

S

YS

TEM

R I A

ON

O

900

1:2

00 8

S S

Products are manufactured under an

ISO 9001 quality management system

Wood's Powr-Grip products are sold through authorized dealers.

Rev. 3.9/ 07-15 Metal Troubleshooter

1MTS

Inspecting and Testing the Cup for Leakage

To INSPECT THE SEALING EDGES of the vacuum pad for roughness or foreign material, slowly draw your finger along the entire length of the sealing edges. Examine the sealing edges for cuts by bending the edge of the pad face towards you to create a hump, turning the hand cup as necessary. If cuts or cracks are present in a sealing edge, a V-shaped gap will appear. Any pad that exhibits a gap or excessive roughness in a sealing edge must be replaced.

To LEAK-TEST THE HAND CUP, attach it to a clean, smooth, scratch-free piece of glass or metal for approximately 2 hours. The red line on the plunger serves as a vacuum indicator:

If the red line does not appear during the test period, the cup is usable; if the red line does appear, perform general maintenance and repeat the test. If the problem persists, check the

Troubleshooting Guide (overleaf) to identify possible causes and appropriate corrective actions.

If these measures do not restore the cup to normal performance, contact the Wood’s Powr-Grip

Customer Service department or an authorized dealer for assistance.

Environmental conditions can affect product performance and longevity; consult the product instructions on www.WPG.com or contact a Technical Sales Representative for more information.

Based on product information at time of publication.

32620

PARTS AND ASSEMBLY

1 90510 Handle

2 90520AM Plunger Assembly, Metal

90154AM Plunger Assembly, ABS

4

3

5

6

7

51506

60024

10002

8

9

61552

61514

10 10008

11

90524AM Plunger Assembly, with Audio Alarm (WBP)

90158AM Plunger Assembly, High Elevation

49486T Vacuum Pad, 8" [20 cm] Dia., Flat (G0695)

49488T Vacuum Pad, 8" [20 cm] Dia., Textured Surface (G0695TS)

49506T Vacuum Pad, 9" [23 cm] Dia., Flat (G0725)

49520T Vacuum Pad, 9" [23 cm] Dia., Concave (VPCS9)

49586T Vacuum Pad, 10" [25 cm] Dia., Concave (G0750)

90500 Valve Block with Release

Lever & Guard

Valve Guard

Air Filter

Handle Screws (6)

Check Ball

O-Ring

Valve Screws (2)

Red Line

29335

29334

29338

29342

28502

Not Shown

8” [20 cm] Case, Grey

8" [20 cm] Case, Black

9" [23 cm] Case, Black

10" [25 cm] Case, Black

Plunger Lube

TROUBLESHOOTING GUIDE

PROBLEM CAUSE

Cuts on sealing edge

Slow leakage

Severe leakage

Jammed or sluggish pump

Pad slips when attached

More than 10 strokes needed to apply

Dirt or lint inside pump

CORRECTION

Replace vacuum pad.

Wipe inside of handle with a soft cloth. Check for contamination on

U-cup or button.

Apply a light coating of plunger lube inside handle.

Dry pump

Scratches inside handle (between midpoint and closed end)

Release valve pad contamination

Contaminated pad face

Release valve O-ring leakage

Valve stem leakage

Severe contamination

Gouges or cuts on sealing edges

Broken handle or release valve

Dry pump

Obstructed release valve stem

Severe contamination

Dented handle

Bent plunger

Contaminated load surface

Contaminated pad face

Excessive glaze or wear on pad face

Any of the above

Check ball sticking

Replace handle.

Sealing edge not contacting load surface

Open release valve and blow valve pad clean with air hose.

Clean vacuum pad.

Tighten valve screws and/or replace O-ring.

Adjust stem for better alignment.

Clean plunger assembly and inside of handle.

Replace vacuum pad.

Replace handle / release valve assembly

Apply a light coating of plunger lube inside handle.

Remove obstruction (through suction inlet behind air filter).

Clean plunger assembly and inside of handle.

Replace handle.

Replace plunger assembly.

Wipe surface clean. If necessary, wash and allow to dry.

Clean vacuum pad.

Replace vacuum pad (at least once every two years).

Perform general maintenance.

Clean check ball and seat. Replace check ball if rough.

Remove handle screws and separate vacuum pad from handle.

Determine whether handle or pad is bent and replace as appropriate.

Disassembly Procedures

Remove Plunger Assembly from Handle

Grasp the head of the plunger assembly and pull it straight out from the handle. If the plunger assembly is too tight to be removed this way, it is best to return the cup to the factory for repair.

Replace the plunger assembly if the plunger housing is bent or dented. Otherwise, wipe the plunger assembly clean with a soft, lint-free cloth. Be careful to keep the plunger assembly clean and free from contaminants when it is not in the handle. Disassembly of the plunger assembly is not recommended.

Remove Release Valve from Handle

Remove the 2 screws holding the release valve to the handle. Carefully slide the valve stem out from the nipple on the vacuum pad. As the valve is removed, the nylon check ball may roll out; be careful not to lose it!

Remove Handle from Vacuum Pad

Remove the 6 handle screws, and separate the handle from the pad. Wrap a small dowel or rod with a soft, lint-free cloth and wipe the inside of the handle, to make sure it is clean and dry

(lubricant-free).

Assembly Procedures

Inspect and Attach Handle to Vacuum Pad

Carefully examine the inside of the handle for scratches and contaminants, using a flashlight for illumination. Scratches between the mid-point and the closed end of the handle can cause leakage. Scratches near the open end of the handle rarely present a problem. Make sure that no lubricant remains inside the handle. Then place the handle on the pad so its nipple fits through the large hole in the base plate near the closed end of the handle. Align the screw holes and reinstall the handle screws.

Reinstall Release Valve on Handle

Apply a light coating of plunger lube to the valve stem. Make sure the check ball and O-ring are in position, and slide the valve stem into the pad nipple, keeping the O-ring against the closed end of the handle. Place the valve guard over the release valve and align the screw holes in the guard, valve and handle. Then reinstall the screws. Even when the screws are tight, the valve may not always appear to fit flush against handle end plate. This is normal.

Reinsert Plunger Assembly into Handle

Using a soft swab, apply a ring of lubricant around the inside of the handle, at a point about 1"

[25 mm] from the closed end. Keep the open end of the handle as dry (lubricant-free) as possible.

Silicone lubricant is recommended and available in appropriate quantities by contacting Wood’s

Powr-Grip Customer Service. Do not use improper lubricants in the handle.

Insert the U-cup end of the plunger assembly into the handle, and push until the plunger assembly begins to tighten; then seat the plunger assembly with one strong, swift motion. Operate the plunger to spread the lubricant, thoroughly coating the outside of the U-cup by twisting the plunger as it moves. Now the cup is assembled and ready for testing.

WARNINGS

Wood’s Powr-Grip has taken great care to produce the most reliable vacuum-operated handling device available. Nevertheless, mistreatment or misuse may damage a hand cup or otherwise create conditions which could cause the hand cup to fail, resulting in an unexpected release. The following warnings are offered to help users avoid most potential hazards.

Failure to observe WARNINGS could damage the cup or the load, or cause injury to the user.

• Do not use the cup with loads that exceed the load capacity.

• Do not use the cup to support a person.

• Do not place the pad face against surfaces which could damage the sealing edges.

• Avoid conditions that could cause the cup to slip or to disengage prematurely, such as: contaminants, cuts or scratches in the pad face or load surface; applying the cup to porous materials; or applying pressure against the pad edge.

• Do not use the cup to lift when the red line is visible. If the red line reappears testing.

frequently, discontinue use and follow the instructions for general maintenance and

• Do not allow anything to interfere with free movement of the plunger while the cup is attached. This could prevent the red line from warning the user of vacuum loss.

• Do not touch the valve release lever while lifting.

• Do not attach 10" [25 cm] diameter cups (models N6450 & N6300) to thin, fragile materials.

• Do not use harsh chemicals (such as solvents or gasoline) or unauthorized rubber cleaners and conditioners to clean the cup. See www.WPG.com for more information.