How do you properly tension your serpentine belt?

[jessesYaris]

Replaced mine a few months ago as the original was squealing so loud it was waking the neighbours...

Tried my damnedest to apply tension to it while tightening the bolt on the generator and it still squeals a bit from time to time when I start it up.

I assume I didn't apply enough tension?

How do you do it properly?

[bronsin]

It’s a little tricky as there’s no tension adjuster. I just keep trying until it doesn’t squeal. But there’s a caveat. Put too much tension on it and it might damage the water pump. That’s one thing Yaris Suffers from one and 100 have bad water pump prematurely.

So maybe a little squeal is OK?

[bronsin]

One thing I forgot to mention. I would only use a dealer supplied belt. They might be expensive but they last a long time.

[bronsin]

Careful when tightening and loosening the alternator bolt. A camshaft sensor is near one of them. It’s plastic and easily damaged!

[jessesYaris]

Thanks again, Bronsin!

I think I'll leave it as is then as there is hardly any squeal at all now.

[Leegamer]

I usually adjusted mine during the spring and fall. Otherwise it seems like the change in temperature and/or humidity would cause it to start squealing. Not sure if it was making the belt stretch/shrink/etc...but the first time I did it my bolts were almost impossible to break free.