new here and couple ?'s

My wife car has about 120k miles...I try doing most of the work on her car that i can. Over the years its been mostly breaks.lol

she has had a couple lexus cars (I only buy toyota/lexus for her) and this one is now at 120k miles. we bought it used with 20k miles and have done nothing to it but brakes and just recently replace orig. battery.

I know this car has timing chain but i know water pump is going to start to fail soon. Should i wait for it to start leaking or just replace now? I hate to fix something that is not broke.

My other lexus, ES330 we replaced at 120k cuz it had a small leak. this car has 190k miles now and have only had to replace alternator. brakes are a common this with my wife so i've done that like 5 times.

If i do waterpump what else should i replace now that car has 120K miles?

 

If it's not over heating I'd leave it. As for what to replace when doing the pump.

Thermostat
Inspect the upper, lower radiator hoses. If ballooning at the clamps replace. Use only constant tension clamps as replacements.

If you can get to the coolant sensor maybe too

Fill with Toyota pink coolant, and bleed the system.