Re: Spider Rear Brake Pads
It is possible that the pads are too thick! There are instances of different applications using pads which have the same backplate but different friction material thickness; an aftermarket manufacturer will often cover the whole market with just one product. Have your new pads got anti-squeal shims on the back? If so, that may be the cause of the problem. Aftermarket manufacturers will copy the OE product dimensionally; if the aftermarket product has a shim but the OE pad didn't, the pad is effectively thicker by the thickness of the shim.
If the handbrake cables are not properly adjusted they can cause problems. Is there any tension in the cables with the lever fully 'off'?
As a last resort you could remove a small amount of material off the friction faces to make the pads fit, but caution is needed! Firstly, if you use an abrasive such as emery you may leave grit particles embedded in the pad - these will score the disc. Secondly, the pad may well have been through a scorch process in production. Scorching is done after final grind; the friction face is heated (different manufacturers use different methods) to the temperature it will reach in service. The curing temperatures used in manufacture are fairly low, so the first time the material is brought up to working temperature gases will be produced; if this happens in service, the result will be brake fade. Scorching helps eliminate this; however, the scorching doesn't penetrate very deeply into the friction material - remove too much & you may be into virgin material.