(2007) Replaced coolant and inverter pump 3 times in past year, still not lasting

They screech when dry. Is it? Fleabay and AMZN crap are fakes. Get OEM

 

These are actually very good points. The inner layers of the hose could've partially peeled away or collapsing, causing intermittent blockages. It's rare, but it does happen.

 

It is a common problem with ICE lower radiator hoses if the radiator is partially blocked.
The manufacturer adds a wire "spring" inside the hose to stop it collapsing, but if the cooling system has been neglected, that steel wire rusts until it breaks, then the hose collapses under load .....

T1 Terry

 

This time I installed a genuine Toyota pump.

 

Because it is most likely that the noise is not coming from the inverter pump.

When you "start the car" (go to ready), the ECM runs the Coolant Heat Storage pump for 5-10 seconds to pump hot coolant out of the thermos tank and into the engine.

That pump is mounted behind the tank in the left front corner (ahead of the tire) - very close to the inverter pump.

It is not uncommon for the CHS pump to "squall or screech" when it gets worn. You might also hear it a few seconds after turning the car off. The sound can change with different ambient temperatures.

Mine made noise for a couple years - I eventually got tired of it and put a new one in.

An easy check - press power button 2x without stepping on the brakes on a "cold" morning. The car will turn "ignition on" and run the inverter pump - but won't go ready and won't run the CHS pump. See if it still makes noise.

Posted via the PriusChat mobile app.

 

Lower the front part of the plastic shield which goes around the driver's side front wheel well and it will reveal the bottom of the thermos and this pump.

 

I think you are correct, thanks very much!