Problem with performance pads, squeal under light pressure.

I put the Porterfield R4-S on the car, but porterfield said not to use the factory anti-squeal shims. They did have some for the rear but not for the front. So I didn't install them on the fronts. Problem is today under light braking pressure, loud squeal. I did bed them in correctly. But today I did the stoptech procedure which said 60-5mph without stopping. After I did this, no more squeal under light pressure.

So what gives? Im thinking of putting the anti-squeal on, but if it's not making any more squealing now, fill me in what everyone's thoughts are.

 

watching!!
i have the same pads. i used the stock shims though and the squeel is annoying to an extreme!!!!

 

yeah im not even using any shims yet, so now i wonder would using them actually help or not.. hmmmm