I have replaced the front rotors and pads on my 2001 v40 and am left with an awful clatter on the left side at slow speeds when I apply the brakes. I have taken the pads out and tried 4 times to apply 2 different brake squeal products, both from CRC. One is a spray paint type that creates a thin but very stick layer on the pad backing, the other is a thicker product which I usually use when doing break jobs. I have never had this problem before and it is driving me nuts. Any ideas as to what else I can try to get these pads quite?

You do mean "clatter" and not "squeal", right?

I wonder if you have the wrong pads.
Maybe they're just a bit smaller than what is supposed to be in there.

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"Differences of opinions should be tolerated, but not if they're too different' - Sharon Craig

Yes, clatter not squeal. In my opinion it if definitely cause from brake pad movement. The spring on top is seated properly. They are the correct pads but I guess there could be a slight defect in the size. When the are seated in the caliper you can't move them with you hand.

Usually, when a pad is not seated correctly or the spring clip isn't doing its job, the brakes make noise when going over sharp bumps but not when applying the brake.

I would try removing the claiper and rotor and cleaning again with brake fluid. Both the rotor and pads.

Tip: clean the car side of the rotor first, then mount the rotor. After the rotor is mounted, clean the outside. Then clean the pad brake surface, blotting with a clean cloth and making sure nothing touches the pad surface as you put them on. Verify that there is no pad movement before you put the spring on.

Find a lonely road and 'burn' in the new pads.

I think you meant clean with brake CLEANER not brake FLUID.
You would not want to get brake fluid on the pads.
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"Differences of opinions should be tolerated, but not if they're too different' - Sharon Craig

Aaaarrrrrgh! Thanks for the correction.

Make sure the caliper is on firmly. take off the wheel and give it a good jiggle, try the old pads and see if it is gone. Does your caliper piston move out all the way as it should? I have a rubbing noise that was intermitent, but i took the pads out cleaned them and put them back and all was good. Do you have the metal shims?

Is there an anti rattle spring? I'm sorry I don't know this car. But sometimes I've forgotten the spring. It will make noise without the spring properly installed.
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I'm stuck on Volvo and Volvo's stuck on me....