1. Radiator leakage failure. Common failures are leakages, mainly caused by corrosion, perforation, and mechanical damage. Radiator penetrant inspection may be carried out with a sealed tester.
(1) when inspecting the leaking part, first remove the radiator cover and inject cooling liquid into the cooling system.
(2) Install the radiator cover tester and apply 117.6kPa of pressure to the cooling system with the radiator cover tester. Then, in turn, check the radiator, the water chamber and radiator core, pump and hose connections for leakage phenomenon.If a leak is found, Welding and repairing with tin.
(3) If the leakage is in the upper or lower chamber, it can be covered with a thin copper cover and welded over the broken part.
If the leakage in the radiator core outside of the water pipe, soldering iron repair or thin copper cover welding.
If the internal water pipe leaks, it is often repaired by acetylene welding.
2. Check radiator temperature control switch
The radiator temperature control switch is wax sealed and the color is black.The switch can be checked in two ways.
(1) On-board inspection: turn the ignition switch to the "ON" position, remove the joint of the temperature control switch and ground it. The fan motor shall rotate. If not, the fuse and fan motor shall be checked.
(2) ①Component inspection: select the multimeter as the resistance.
②Component inspection: the multimeter is selected as the resistance, the two multimeter probes are connected to the wiring terminal and the housing of the radiator temperature control switch respectively, and then the water temperature is changed to observe the dynamics of the pointer of the multimeter. When the cooling water temperature reaches (92 + / - 0.5) ℃, radiator temperature control switch conduction, multimeter pointer said connected;When cooling water temperature starts to drop, the radiator temperature control switch conduction, still until the cooling water temperature dropped (87 + 2) ℃, radiator temperature control switch to cut off and the multimeter to cut off the pointer instructions.
（3） Inspection and maintenance of radiators and related components.
①Special attention should be paid to the radiator core pipe knock - off deformation damage and water leakage.
②Special attention should be paid to check whether there are weeds, dirt and other blockages of the radiator core, and clean and clean when necessary, so as not to affect the heat dissipation performance and avoid scraping the core tube in operation.
③Pay attention to check and ensure that the belt and cone sleeve cone surface accuracy.The taper degree of belt pulley taper hole and cone sleeve should be consistent. After pressing the cone sleeve into the taper hole with the thumb, it is required that the small end of the cone sleeve should be 2-3mm lower than the end face of the belt pulley taper hole, and the cone surface has good contact.
④Check that the belt wheel fastening nut at shaft end is really pressed.Adjust if necessary.
⑤Pump shaft end nut should be tightened, tightening torque in line with technical requirements.
⑥The anchor nut of the radiator shall be tightened in time if it becomes loose.The fan blade should be repaired or replaced with new parts in time. The screw of the engine foot is loose and should be repaired when the whole machine moves forward.
(3)Maintenance of radiator mandrel
If you find leakage of radiator core tube, remove it for inspection.First determine the leakage site, and then the surface treatment clean, and then solder with soldering tin.
After welding and repairing, generally use compressed air (117kPa pressure) for pressure test, and keep it for 1min without leakage, otherwise it will be repaired again.