Hi, 2500 hours is nothing! Our ford has got 15,000 on it and only just done a rebuild, also keep in mind machine hours are not the same as human hours, diesels count there hours based on a set engine rpm, most are around the 1800rpm mark but the do differ. What this means is you can only take the hours as a ruff guide. The example being if the previous owner has done lots of work with it but only at low rpm ( most hobby users) then the engine is rarely under it's rated load, then this can lead to worn bearings and carbon buildup just to name a couple of options. This engine would show low hours but might have problems. On the other hand, an engine that is run flat strap all the time but not under load is going to gain hours quickly, so that kind of operation is going to have done damage aswell. My point with this is don't base your decision on hours as it's only a very small part of the story.
I would be more concerned about how the tractor looks, how easily does the engine start? When it first starts what comes out the exhaust? when it's running and you rev the engine does it respond quickly (good) or slowly(fuel timing problems) does it bellow Hugh amounts of smoke? Take it for a test drive, try it in all the ranges and gears, do all the gears feel the same, even across the ranges, some times driving a tractor in high range all the time can mask gear problems when you put it in low range and vise versa. How Does the clutch feel? Are the brakes good? With the tractor in a low gear and decent rev's stamp on the brakes, does the engine die or can it hold on, or do the brakes not do anything? This simulates the tractor under load. and will give you good insight into the engine's ability to pull. Feel the steering and watch the wheels is there any slop? If there is this could mean hydraulic problems ( presuming power steering) once the tractor has been running for a while check the temp gauge, it should read around 80 deg C, have a feel of the bottom of the radiator, carefully it will be hot, but should be around 50deg C have a good look at all the greasepoints do they look like fresh grease covering up old caked up grease? Or does it look well maintained? With loaders and back hoes, look for wear on pins and joints, with the implement off the ground move it side to side by hand ( machine off) and see how much movement you get? If bush's are good you should get almost none.
Check for oil leaks around the transmission, these can be costly to fix, and the old rule is if oil can get out, dirt can get in.
Follow these steps and you should have a really good idea of what your up for.
