How to Fill the Oil Reservoir in a Sears Craftsman 3 1/2 Ton Floor Jack

Craftsman professional floor jacks are extremely efficient devices that will lift and hold up to 4 tons in a safe and secure manner. But a monthly check of the oil level in the master reservoir is a must. Failure to maintain factory specifications with regard to the oil level will cause premature failure of the jack or poor performance. Fortunately, proper checking and filling of the oil reservoir is a simple task.

Things You'll Need

  • Allen wrench set
  • Clean rags
  • Small plastic funnel
  • Hydraulic jack oil
  • Place the jack on a flat, level surface. Lower the jack so that it is in the full down position. Remove the magnetic tool tray located between the two rear wheels on the top of the jack. Set the magnetic tool tray aside.

  • Remove the oil-filler plug using an Allen wrench. Wipe away all dirt, grease and debris from the oil-filler plug and set it aside. Wipe away all dirt, grease and debris from around the oil-filler hole with a clean rag.

  • Inspect the oil level inside the oil-filler hole. The hydraulic jack oil should be visible 3/16 inch above the inner cylinder wall. If the oil is below this level, high-quality jack oil must be added.

  • Place the small end of a clean plastic funnel into the oil-filler opening (hole). Add a small quantity of hydraulic jack oil to the funnel, and allow it to dissipate into the hole. Wait 30 seconds, then recheck the oil level (3/16 inch above the inner cylinder is good).

  • Continue to add oil as needed, and keep rechecking the oil level. Do not overfill. Replace the oil-filler plug when the proper amount of oil has been added. Tighten the oil-filler plug and replace the magnetic tool tray on top of the jack.

  • Test the jack for full operation by running it all the way up (full raised position) and all the way down (flat position) with no load on the jack. Perform this test three times with no load on the jack to dissipate any air bubbles in the oil. The jack is now ready for use.