A forklift must be checked properly and given a test run prior to buying it. This applies especially to trucks being obtained on-line. It is really essential to find possible issues with trucks purchased from companies on-line.
Starting the engine from cold is a great idea. Note whether there is excessive smoke and the ease with which the engine turns over. This is especially vital with IC engine trucks.
Testing the performance of the truck in challenging situations must be included in the test run. An operator who is trained can operate the truck in reverse and forward, up the ramp.
You can inspect an IC engine truck yourself. On a clear part of floor, run the truck around for a few minutes while a qualified driver tests the hydraulic functions. Then, examine the ground beneath for signs of fluid leakage. Even seemingly insignificant leaking could lead to serious problems that will be really costly to repair later on.
A trained person must inspect the chains and masts. Check with and without a load that the mast operates well. Watch for sticking or 'binding' of the mast. A warning sign is play in the mast channels or between the fork carriage and mast. Another is creeping forward or creeping down of the mast when loaded. These could be symptoms of issues with seals, ram or valve.
If the truck is not new, the mast might have been changed at some time. Make certain that the mast and any fitted attachments follow the rating plate on a truck. Make sure that the sideshift is not sticking when loaded.
When checking the forks, look closely at the heel thickness for damage or wear. The manufacturer of the truck specifies minimum thickness. A loose fit could mean the hanger points or carriage are worn. Watch for cracks on the arms at mountings and heels.