Regardless of whether you want to sell a Mercedes truck as a used car or a used excavator, these machines are typically heavily used. As with the purchase of a private car, the overall visual impression counts here. A construction machine or a vehicle that has already been damaged from the outside and is badly dented does not have a good inkling of the interior.
You can see details especially when you look more closely. You should make sure that chains and tires are in good condition, because new purchases can quickly become expensive here. With small wheel loaders, for example, a set of new tires costs 1,500 euros, with track excavators, several thousand euros only come together for new chains.
The connections and lines of the hydraulics in construction machines should also be checked (especially for corrosion and leaks). You do this by warming up the device and then moving all the joints and attachments. If you don't notice defective hydraulic pumps when you buy, you pay a lot. With older mini excavators, for example, it is hardly worth repairing the hydraulics.
If you want to be on the safe side, you should also request machine test reports and proof of maintenance. You should also be granted access to the logs of the statutory safety and UVV tests. If necessary, you can protect yourself against costly repairs with various guarantees