Lesson 5/Learning Event 2
If you do not have a pressure tester, make a visual inspection of the radiator cap. Check the rubber sealing
surfaces of the pressure and vacuum valves of the cap. Check the valves for freedom of operation. If the cap
is damaged or worn in any way that will prevent it from sealing or operating, replace it.
To further ensure that the radiator cap will seal, clean the radiator filler neck and examine it for damage.
Install the cap by placing it on the radiator filler neck and turning it clockwise as far as it will go. If the cap
fits properly, two distinct clicks or notches can be felt as it is being turned.
Radiator hoses should be examined for leaks, condition, and proper installation. If the hose connections are
leaking, tighten the hose clamps and recheck for leaks. Hoses that are collapsed, cracked, or have a soft spot
should be replaced. Ensure that the hoses are positioned so they do not rub against other parts. All clamps and
hoses should be installed over the connections far enough to provide secure fastening. The normal pressure in
the cooling system can blow off improperly installed hoses.
If the vehicle is equipped with a shroud, examine it for secure mounting bolts, position, and condition. Replace
or tighten any missing or loose mounting bolts. Ensure that the shroud is positioned so the fan will not hit it.
If the shroud has any large cracks or is excessively bent, it should be replaced.
Fan belts must be checked often to ensure that they are in good condition and properly adjusted. Belts that are
badly frayed, worn, or cracked should be replaced before they break in operation. When more than one belt is
used, they must be replaced in matched sets.
If a belt is adjusted too tight, it will put undue strain on the water pump and generator bearings. If the belt is
too loose, it will prevent the water pump and generator from operating properly. This can cause an overheated
engine or undercharged batteries.