A forklift should be checked properly and given a test run before buying it. This applies particularly to trucks being acquired on the World Wide Web. It is really vital to detect potential issues with trucks bought 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.
The test run must include an inspection of the truck's performance in challenging situations. A skilled operator could drive the truck in forward and reverse, up the ramp.
You could perform your own inspection of an IC engine truck. On a clear part of floor, run the truck around for a few minutes while a trained driver tests the hydraulic functions. Then, examine the ground underneath for signs of fluid leakage. Even seemingly minor leaking can indicate serious problems that will be really pricey to fix later on.
A qualified person should check 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 mast and fork carriage. Another is creeping forward or creeping down of the mast when loaded. These could be signs of issues with ram, valve or seals.
The mast may have been changed at some time if the truck is not new. 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.
When checking the forks, look closely at the heel thickness for damage or wear. 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 heels and mountings.