Squeeky front brakes

Afternoon all,

Just a quick one, I've got this annoying problem where my front brakes constantly squeal when I'm in slow moving traffic, not sure whether I've got a sticking caliper or grit in the pads, but it's driving me mad!!! Went to take a look last night, but just as I was about to remove the caliper the Haynes manual states that you must renew the bottom caliper bolt everytime it's taken out................... Why??? Has anyone else ever done this, seems like another ridicules use of stretch bolts!!

Cheers