2. The pump has a control hole for draining liquid (shown by arrow). When the pump seal fails, coolant leaks through the inspection hole. To find this hole, you need to illuminate the space behind the driven flange of the pump, directly under the shaft.
3. Bearing wear can be determined by rocking the pump up and down and by the characteristic howling sound coming from the front of the engine. A slipping drive belt can also produce a similar sound, so you can make the wrong conclusion about the pump malfunction. To eliminate the sound from the belt, spray on a special compound for car belts.
(The material is reprinted from an online resource: TOYOTAMAN.ru)