Does belt dressing spray work?

[dom]

I always see this stuff on the shelves and sometimes wonder if it works.

And if it works does it last?

[dBrong]

A 'V' belt transmitts force through through the sides of the belt contacting with the sides of the pulley.

Belts age in different ways: They usually get hard and begin cracking at the lower portion on the 'V'. Their sides get 'glazed' - and don't grip the sides of the pulley as well, thus they slip and that's the squeal you hear.

Belts shouldn't squeal. When they do, it's time to replace them.

IMO belt dressing is pretty much useless.

[grouch]

I always see this stuff on the shelves and sometimes wonder if it works.

And if it works does it last?

They are pretty much a waste of time and money. The only time I've ever seen them do a good job is after getting a car that has been detailed by a dealer. They spray silicone everywhere under the hood and it will eat rubber up. Belt dressing will slow it but if you use it when the belt squeels, a little goes a long way. Usually, you'll get too much on and it will make the belt slip more.

If the belt starts to howl, find out why and then fix it. Don't waste your money on dressing. If the belt is old, replace it. If the tensioner is loose, fix it. If something driven by the belt is dragging, find out why and fix that. Belt dressing is a band aid solution and won't last.

[Eric]

I always see this stuff on the shelves and sometimes wonder if it works.

And if it works does it last?

What Doug said.

Belt dressing can temporarily make a squeal go away. It doesn't fix anything!