If you want to buy second-hand machine, when see a car, be sure to please a senior old tractor driver to help, to commissioning, buy second-hand machine, don't covet petty gain, feel much lower machine than I expected, that which must be a issue, so be careful shopping.
Buy anything at first glance is appearance, excavators, too, experienced users, one eye can estimate the vehicle usage, how many hours of work, how wear, etc.
So what appearance to see, what do you think?
This is also a lot of troubles users, then introduce you to what appearance look.
First, large excavator forearm, observe excavators have big arm and forearm fractures, trace of welding, if there is a crack, prove machine used to dry condition is poor, badly damaged machine.
Such a machine if buy, is not good.
Second, observing the oil cylinder to have the trace of knock against, if there is a knock against, prove that the machine has a serious damage, oil cylinder will keep oil, even if change new oil seal also continued to leak in a short period of time, so buying second-hand machine, check the oil cylinder is also very important.
Third, check the four-wheel area, the first observation of driving wheel, guide wheel.
Fourth, commonly known as 'heart' of excavator engine, so be very careful when buying second-hand machine check engine, trial did when listening to the engine noise, power strong, working whether appear off speed phenomenon, at the same time also can look up into the system, whether the exhaust emission is larger, if the displacement is larger that partial engine working time is long, need an overhaul, in addition, the blue smoke coming observed whether or not when you start the engine, we haven't start after started working there is smoke, is proved that the engine is to burn the oil.
Fifth, buy used machines to inspection of the rotating motor, observe whether the rotation, has made a lot of noise during rotation, which parts need to see if there is a noise is noise, again carefully look at the rotating chassis gap, second also want to scrutinize the distributor of excavators, as a result of the distributor function mainly control the action of each work, so when buying used test must see excavator each work action is coherent, if there is a pause.
Mining is strong, the test method is to dig up a bucket of soil and then referred to the highest observed whether each cylinder inside leaking phenomenon, these are important considerations in buying a used car, so be sure to carefully choose the car.
Sixth, the hydraulic pump is the power of the hydraulic system components, its effect is the prime mover can convert the mechanical energy of liquid pressure, oil pump in the hydraulic system, it supplies power to the entire hydraulic system.
So it is also important to check hydraulic pump, buy second-hand machine should use hand to touch the hydraulic pump, watch for shake hand feeling, then check that the hydraulic pump have crack, whether any serious circumstances, to carry on the test, observe whether hydraulic pump is strong, no noise.
Seventh, check the electrical system, whether the circuit can work normally, and then into the computer system to check the mainboard, if you can see all the work after entering the system, such as revolution, pressure, maintenance mode, etc. , prove that computer board is normal.