1. If after any of the three checks below, a malfunction of the coolant pump is found out, then it must be replaced immediately.
2. Warm up the engine. Squeeze the upper radiator hose. If the pump is working, fluid pressure should be felt.
3. Using a mirror, check the condition of the pump shaft seal. If a leak is detected, the pump through the control hole, replace (see photo).
4. If increased noise is constantly heard from the side of the pump shaft, then the reason is the wear of the pump impeller shaft bearing. Check the lateral play of the bearing by removing the belt and shaking the pump hub (see photo). If play is felt in the horizontal and/or vertical directions, replace the pump.