Suffered from horrendous front brake squealing whilst away recently. Fitted new (Pagid) pads. Worse than before! Chamfered pads...no improvement. Cleaned up rust from disk edges. No difference. Reapplied copper grease. Slight improvement. Bought a set of shims from Butty's Bits (plain style...my callipers are the non-cutout version which you have to check visually) Also treated myself to a brake tool. Never bothered before and made-do with brute force/clamps and wood etc if required. Thought I’d get a tool for a change (not strictly needed but nice to have.) Got a Sealey one from Amazon as cheaper ones appear to bend. Shims fit perfectly. Applied fresh copper grease between shim and pad. Tool works perfectly. Oh...squeal 90% better. I can live with occasional ones! Both recommended (Remember to check which shims you require; these are the other type...)