Yes, you can occasionally find dump trucks being sold at auction. You can also check this site for used dump trucks in your area: http://www.commercialtrucktrader.com/.
I am not familiar with the company that sells dump trucks nor I do not know somebody right now who is selling such truck but I am pretty sure you can find for sale dump trucks on the government auction website. That is, if you are fine with buying second-hand dump trucks.
Some are. I know one of our contractors who has a Kenworth T-800 dump truck with a 525 Cummins, and that truck will move, I tell you. But a normal fleet truck isn't going to be particularly fast.
a lot who would need to know that
You will have to know the volume truck bed & the rate of spreed to determine the acres.
Need to know the specifics of the dump truck you had in mind. Tandem axle dumps in the company I work for... if they have a 'dirt tub' body, they can carry 16 cubic yards. The ones with the 'rock tub' dump bodies can carry 15 cubic yards.
Need to know the bed dimensions in order to answer this. Freightliner doesn't manufacture the dump bodies - aftermarket companies do.
If you are looking used dump truck for sale in United State or Canada I know the best companies I personally use this company so that's what I was thinking I can suggest to you, if you are looking used dump truck in United State then you can visit KAL Trailers & Leasing - and Canada you can visit Big Rick
The question is far too vague to answer. We don't know the make and model of the dump truck, we don't know if you're referring to an actual button or a knob of the type used in the air brake system of an older vehicle, whether it's OEM or aftermarket, etc.
A number of factors will decide how much your truck will sell for at an auction. Mileage, condition, features, etc. all need to be taken into consideration. This website gives an example of recent auction results. You will know better than anyone what condition your truck is in. http://www.auctiontime.com/List/List.aspx?oalresults=1&etid=6&bcatid=27&lp=trk
Need to know the exact model and configuration in order to answer this. A 26k GVW box truck and a 33K dump truck aren't going to have the same tare weight.
Since there are alot of questions out there about what kind of dump trucks are the best I recommend taking a look at www.autobuyingtips.com. They give you information about everything you need to know about these kinds of trucks.
Please give a specific model. The dump bodies and hydraulic system will be aftermarket, but you there's no way to tell you anything if we don't know whether you're talking about a 1/2 ton C/K pickup or one of the Class 8 trucks Chevrolet manufactured at the time (Chevrolet exited that market in 1980; GMC followed suit when their heavy truck division was bought out by A.B. Volvo in 1988).