On left turns, even just slight left turn, but mostly when weather is humid, I get a loud squeal that sounds exactly like squealing brakes, except I am not applying brakes. May not be relevant, but this is a minivan modified for wheelchair access via a ramp that comes out on the passenger side.
The next time you are out and turning left with the squeal apply the brakes. If the squeal stops then it probably means you’re in for new brake pads shortly. The noise would be coming from a wear indicator on the brake pads and if this guess is correct it will soon be squealing whether you are turning or not.
Either way, what it means is that sooner rather than later you need a good, trustworthy shop to check out what is going on up there.
If my affirming cigroller’s recommendation hastens you to get some attention on the brakes consider it done.
Also check the tire pressure. A low tire, especially on a modified van carrying extra weight, can also cause a tire squeal.
Thanks. I will take your advice right away. Tire squeal seems unlikely because it is a different sound but either way, I am heading for my mechanic.