Coolant pump-mounted fans occasionally require service. They are damaged due to metal fatigue, collision, road hazards, and abuse. Any condition that causes an out-of-balance pump-mounted fan will result in early pump failure. A check for fan problems is a rather simple task.
- Remove the belt(s).
- Visually inspect the fan blade for cracks, breaks, loose blades, or other damage. Is the fan blade sound? If yes, proceed with step 3. If no, replace the blade.
- Hold a straightedge across the front of the fan blade. Are all blades in equal alignment? If yes, proceed with step 4. If no, replace the blade.
- Slowly turn the fan blade while looking for any out-of-true condition or other damage.
- Turn the fan blade fast and look for out-of-true conditions. An out-of-balance fan assembly can lead to water pump shaft and bearing failure. A noticeable wobble or any blade that is not in the same plane as the rest indicates that replacement is in order.
- The fan blade can also be checked by removing it and laying it on a flat surface. If it is straight, all the blades should touch the surface. Never attempt to straighten a damaged cooling fan blade. Bending it back into shape might seem easier (and cheaper) than replacing it, but doing so is risky. Whenever metal is bent, it is weakened.
- If the fan blade fails either steps 5, 6 or 7, it must be replaced. Because of to high operating speeds, it is not recommended that repairs be attempted to an engine cooling fan blade.
- Be sure to clean all mating surfaces and tighten the fan bolts evenly to avoid causing a cocked assembly.