Pallet jacks are a staple of warehouse equipment, particularly for moving shipping or storage pallets around. Although pallet jacks are fairly compact in size, what they lack in structure is compensated by force. These small units can lift pallets with ease, and the wheels on the base make it simple to roll those pallets to their new home. When you're regularly rotating stock or unloading shipments, they are a worthwhile investment. Unfortunately, they aren't fail-proof. If your pallet jack stops lifting, it's important to know how to deal with it. Here's a look at what you should know about a grounded pallet jack.
What Causes a Pallet Jack to Stop Lifting?
The most common reason for a pallet jack to stop lifting properly is an air pocket in the hydraulic system. Since the hydraulic pressure is what's required to operate the jack, any air pocket can disrupt that pressure and keep the jack from lifting. Although the hydraulic system is usually tightly sealed, a worn, damaged or cracked o-ring by the valve cartridge could allow air to seep through. If you're seeing moisture or hydraulic fluid leaking near the bottom of the pallet jack handle, that's a sure sign that you have a damaged o-ring.
What Can You Do About Damaged O-Rings?
If your pallet jack has a leaky o-ring, the only way to fix it is to replace the ring and then fill the hydraulic system with fluid again. You can get replacement o-rings from most industrial equipment suppliers, tool supply centers and similar sources. You'll just need the model number of the pallet jack to be sure that you get the right ring. You can also remove the old one and take it to a supplier for proper sizing.
How Do You Replace a Damaged O-Ring?
- Lift The Jack: Position a set of four jack stands on the floor so that they support the pallet jack forks at each end. You should have one jack stand at the tip of each fork and one jack stand at the end of each fork near the pallet jack body. This elevates the jack enough for you to work on it safely.
- Drain The Fluid: Locate the drain screw on the lower right side of the hydraulic pump, near the rear tire. Put a small bucket under the stem of the drain screw, then use an Allen wrench to pull the screw out. This allows the hydraulic fluid to drain from the system. You may need to pump the handle of the jack up and down a couple of times to flush the rest of the fluid out. Then, put the drain screw back in place and tighten it.
- Disconnect The Lower Lever: Locate the pin that sits on the right side of the pump body, securing the lower lever in place. Use a small Phillips screwdriver to drive the pin out of place. Just place the screwdriver on the pin and tap the handle of the screwdriver with a hammer. The light pressure of the screwdriver should be enough to remove the pin from the lever. Pull the lever off the pump body.
- Remove The O-Ring: Locate the valve cartridge that was covered by the lower lever. Use pliers to turn the valve cartridge counterclockwise. Once it's loose enough, unscrew it the rest of the way and remove it by hand. Then, reach into the ridge of the pump body where the cartridge was and remove the o-ring. Use a clean rag to wipe the whole area clean so that there's no residual debris. This is particularly important if the old o-ring was crumbling or cracked.
- Install The New O-Ring: Put the new o-ring in place of the old one and put the valve cartridge back in place. Screw it in by hand, then use the pliers to turn it an extra quarter to half of a turn.
- Reassemble The Pallet Jack: Put the lowering lever back in place, then insert the retaining pin to keep it there. Tap the retaining pin into place using the screwdriver and hammer if necessary. Once everything is back in place, open the screw at the top of the pump body and fill the pump with hydraulic fluid until it reaches the bottom of the screw threads. Replace the screw, making sure it's tight.
Test the operation of the pallet jack to ensure that this resolves the problem. If it doesn't, you'll need to reach out to a local pallet jack manufacturer like Garland's, Inc.or a repair shop to help you troubleshoot the problem.