Rear brake caliper rattle
This little problem drove me mad. Ever since buying my 2004 147 1.6 eighteen months ago, the rear capilers have rattled which you hear at lower speeds. As soon as the brake pedal is pressed or handbrake pulled on, it stops. I changed the pads early on and hey presto the rattle stopped for a while until the noise slowly returned once the new pads had worn in. You can get hold of each caliper and there is quite a lot of play allowing the outer part of the caliper housing to knock on the back of the brake pad. My friendly Alfa specialist tried copper greasing the sliding pins and back of the pads, but with no success. We tried another 147 in the garage, and it had a lot of play too. Compared to an old MX5 which I used to have, there is far more play built in to the sliding pins and there are no thin metal anti rattle backing plates on the back of the pads which many other types of cars do have. This allows the caliper housing to simply bang away on the back of the outer pads.
Whilst in Halfords the other week, I opened a few different boxes of brake pads, and one set had thin self adhesive rubber backing material on the back of the pads. This I can only presume is to stop the dreaded knocking between caliper and pad.
After a Google search, I found some self adhesive anti rattle brake pad buffers on 'elise parts.com' at around four quid. Seems the Lotus Elise/Exige and VX220 also suffer a similar problem between the edge of the pads and the caliper. These I applied to the outer two 'fingers' of the caliper where they contact the outside brake pad and bingo no more rattle. I cleaned the caliper services thoroughly where the buffers were to be stuck and you will need a piston rewind tool to wind the piston in a little way. Halfords sell this tool for £20. The material is only very thin so guess will not affect the brake performance. After applying these little pads, there is still plenty of play in the caliper but no more metal on metal knocking. I presume they are heat resistant if they can stand up to the riggers of ragging an Elise or Exige around a track! I will have to see how long they last. Hope this helps somebody out there with a similar problem.
By the way, my local Alfa specialist is a new garage 'Italian Car Specialists' in Croston, nr Chorley, Lancs. He is very good!