A forklift should be checked correctly and given a test run before buying it. This applies particularly to trucks being purchased online. It is important to detect possible issues with trucks obtained from businesses on-line.
Starting the engine from cold is a good idea. Note whether there is too much smoke and the ease with which the engine turns over. This is specifically essential with IC engine trucks.
The test run must include an inspection of the truck's performance in challenging situations. A skilled operator could operate the truck in reverse and forward, up the ramp.
You could carry out your own inspection of an IC engine truck. On a clear area of floor, run the truck around for several minutes while a trained driver tests the hydraulic functions. After that, look at the ground underneath for indications of fluid leakage. Even seemingly minor leaking could result in serious issues which would be costly to repair later on.
A trained person should check the chains and masts. Check with and without a load that the mast works smoothly. Watch for sticking or 'binding' of the mast. A warning sign is play in the mast channels or between the mast and fork carriage. Another is creeping down or creeping forward of the mast when loaded. These could be signs of issues with valve, seals or ram.
If the truck is not new, the mast may have been changed at some time. Make sure that the mast and any fitted attachments adhere to the rating plate on a truck. Make certain that the sideshift is not sticking when loaded.
Looking closely at the thickness of the heel for damage or wear must be included in the inspection. The truck's manufacturer specifies minimum thickness. A loose fit might mean the hanger points or carriage are worn. Look for cracks on the arms at mountings and heels.