I have a little experience with dozers, but not very much info on what your looking at.
The new paint job sets of red flags. The only reason to do that is to hide something. Nobody is gonna think twice about buying a dozer with some scratches and wear on the paint.
He's not telling you anything about the machine. This is red flag number two. Playing stupid is just a way to cover his but. He knows what's wrong with it and can probably look at the machine from a hundred feet and know what it is. Why he's not telling you is a sign of what you can expect down the road when you figure out what the problem is.
Telling you what a machine cost brand new and that he's giving you a deal really sets of those red flags!!! He just sounds sleazy to me. But to be honest, that's not very uncommon with used equipment sales people. Just my opinion.
Before you even look at the machine, you need to know where you can buy parts for it. It will break down. How often and how expensive is the mystery.
If you want to own a dozer, you better have a good set of tools and be willing to bust your but doing your own repairs. Nobody wants to come out to help you. Your on your own!!!
My dozer weighs almost 40,000 pounds and has about 170 hp. It's a big machine and pretty much useless on stumps and large trees. I can get them out, but it's a major task that requires moving tons of dirt. The backhoe is allot better for this.
It's good for grading roads, cutting trails and moving dirt short distances. I moved hundreds and hundreds of yards of dirt today with mine. I did the same yesterday and will do the same tomorrow. I burn about 30 gallons of diesel a day and right now with a new engine, about a quart of oil every other day.
Threre's really four main parts to a dozer. Undercaraige, hydraulics, transmission and engine.
Not much to check on the engine. Look at the oil, the water and check for leaks. I looked at a Cat D7 that was priced right, but when I started it up, there was a steady stream of green water coming out of someplace. I didn't want to mess with it, so I passed on that one.
If the engine goes on you, what will you do?
The next one is the big money item. The transmission. Clutches or hydrostatic. Either one will be a pain to fix if it goes out. You will have to run it to get an idea if it's ok. Start the engine, warm it up, and open the throttle all the way. Always run a dozer in full throttle.
Drive forward and see how it tracks. Does it go straight forward? If it goes to one side or the other, this might be a simple adjustment, or a five thousand dollar repair that's just a few months away. Do the same in reverse. Turn it, spin it and run it through some manuvers. If you find it doesn't respond properly just once, you got issues!!!
Put the blade all the way down. It should lift the front of the dozer off the ground. Put it in forward and try to push it. Both tracks should spin evenly. If one is faster than the other, you got problems.
The big wear item is the undercaraige. If it's a solid machine, it could still have a worn bottom end. Do the tracks have a master link? Is the sprocket one piece, or five? If it's one piece, you have to take off the tracks to change the sprocket. One pice sprockets are a royal pain to replace but the five piece ones are super simple.
The next big item and the one you really need to check are the spindles on the tracks. This is what the sprocket grabs when driving. It's also what wears out the fastest and is very expesive to replace. They have to be pressed on and I've heard it can cost $5,000 to have them turned over.
Feel them by hand. Are they totaly round? I doubt it. Is one side round and the other flat? This is what mine are like. This means they have been turned. One side wore out and now I'm on the other side.
The hydraulics will leak after awhile. This is normal enough and the parts are usually around a hundred bucks, give or take, for a rebuild kit. I do my own, but the first one was a real learning experience. I've done about a dozen cylinders now and most have been pretty straight forward. Some are sealed together with loctite and you will need to torch them to melt the loctite to get them off. You will probably need a special spanner tool to get them apart as well.
Run the dozer, get it good and warm and look for leaks. Drive it forward a ways and then get off and look at the area between your tracks for leaks. When the engine is warm, and all the preasure is up on the hydraulics, you should be able to see if there's a leak or not.
Finally, compare prices. I like ebay just to get an idea of what they go for.
www.equipmenttraderonline.com is a really good source for prices in your area.
www.machinerytrader.com is gonna be very high on prices. If you spend the time to check out their links for dealers in your area, you might find what things are selling for, but never consider it as a good source for prices. I also like the local free classifieds. Here its called the American Classifieds. I check it every week for certain items. If you can find a machine that was used on a farm like what you want, you might get a good deal that way.
From what you've said and the sellers attitude, I'd probably walk away from this deal.
Good luck,
Eddie