|
Hi Art;
In my experience (trying to keep customers from complaining of brake noise....) I have found that the brake pad material ( or manufacturer ) is the single most important factor in reducing pad squeal. This includes other car makes like Mercedes and BMW which also use the Ate calipers. I set the piston alignment by eye, within a few degrees. I also use a square file to remove any burrs in the caliper mouth where the pad backing plate edges abutt. I clean the pins on a wire wheel, and them spray them with WD-40 and wipe them dry. No never-seeze on the pins. With the right pads, no squeal, happy customers.
For Volvos in particular, I find the PBR Metalmaster pad is the best - and I usually use a single shim with a bit of never-seeze between the shim and the pad backing plate. Sometimes two shims are needed, but only with a cheaper brand I also use on 240's only. One steel shim, one black rubber coated. The 740's seem to be even less tolerant of brake pad material. I use metal-master's or the factory pad on the rears. I have never known a factory pad (the very soft ones) to squeal, but they are terrible for dust and wear out in 18 months.
For front brakes on 240's, the Metal-master, but for some two piston 740 front brakes (88-89 in particular, with the rotor inner vents outboard), only the factory pad seems to give a good pedal feel, no "morning sickness", and quiet operation.
It can't hurt to align the pistons carefully - and I wouldn't dimiss anyone who does, but I have found the pads to be the culprit in almost every case.
|
