How to Add Oil to Floor Jacks

Floor jacks are useful tools that should last for many years with very little maintenance. Although floor jacks do not "consume" oil, it may leak out from one of several places over time. For safety's sake, it is always a good idea to check the various components of the jack during the oil filling procedure to determine whether the jack is safe to use. The reason for having to add oil should always be investigated as part of this maintenance procedure.

Things You'll Need:

• Clean rags
• Hydraulic jack oil (or as suggested by manufacturer)
• Small funnel
• Flashlight
• Slotted screwdriver or Allen wrench

1. Place the floor jack on a hard, level surface

Place the floor jack on a hard, level surface. Put the jack in the down position by opening the release valve--the valve that when opened allows oil to flow back into the main oil reservoir located at the bottom of the jack, thus lowering the ram piston. Look for any oil seepage around this valve. Wipe off the area around the release valve with a clean rag.

2. Locate the oil fill plug

Locate the oil fill plug. On older jacks, this plug may be hidden behind a removable cover near the bottom of the jack. On newer jacks, this plug is usually located near the top of the oil reservoir (cylinder containing oil when the unit is in the down position). Once you've located the plug, look for any oil seepage around the plug, and wipe the area clean with a rag to prevent contamination during the refill step.

3. Remove the oil fill plug by unscrewing it with a large slotted screwdriver or an Allen wrench

Remove the oil fill plug by unscrewing it with a large slotted screwdriver or an Allen wrench, depending on the manufacturer. Once the plug is removed, use a flashlight to look into the oil filler hole. The oil level should be 1/8 inch below the neck (opening) of the oil filler hole.

4. Add oil by inserting a small funnel into the oil filler hole

Add oil by inserting a small funnel into the oil filler hole, then slowly add a small quantity of jack oil. Remove the funnel. Wait 30 seconds for the oil to dissipate, then check the level with the flashlight method again.

5. Replace the oil fill plug, and wipe up any spilled hydraulic jack oil

Replace the oil fill plug, and wipe up any spilled hydraulic jack oil. Raise the jack to the full up position by pumping the pump handle. Look for any oil seepage around this handle. Once the jack is in the full up position, inspect the ram piston for oil seepage. The ram piston is the component that actually raises the item being lifted during the jacking process. Wipe away any oil from the ram piston.

6. Release the jack to the full down position

Release the jack to the full down position. Inspect the area under the jack for oil seepage.

Tips and Warnings

If you found excessive oil around any components of the jack during the oil filling process, the jack may require oil seal replacement. Oil may be added frequently, but excessive oil loss will reduce the holding power of the jack thus rendering it unsafe in some conditions.

Do not use brake fluid in a hydraulic jack. The alcohol content in the brake fluid will destroy the seals in the hydraulic jack very quickly.

Video: How To Add Oil To A Floor Jack

Helpful comments on this video:

• I have a Crewline 1.5 aluminum jack and it does not pump for the first few inches of handle travel which makes it unusable if it has to go way under a car. It also stops pumping up before it gets to the top. The manual points to the top and says "Fill hole" but there are 3 possible fill holes. There is a big fastener with a slot in it that has another slotted thing inside if removed (safety valve?) Then a hex nut with a small philips screw in it and says "Breather valve" and then a plug that takes a 5/16 allen wrench. The philips screw starts hitting resistance after opening a few turns so I did not remove it. The big slotted one is already full. If I cycle the jack and lower it, some bubbles will come out but the oil level goes up when that happens so no more can be added. If I start loosening the allen screw, oil just gushes out no matter where the handle jack ram is or if the release is open or closed. What gives and how do I get it to function properly. I added to the big slotted hole in the past but like I said, it is already full.
• Did not have any screws in mine, rubber plug. It still won't work.