I think most Mercs don't have the shims. The lubricant is required when there are no shims, you apply it sparingly to the back of the pad, where it contacts the piston, DO NOT GET ANY ON THE FRICTION MATERIAL!
If you don't use the lubricant then you may get squealing when the brakes are applied.
If you buy the pads with shims then you shouldn't need the lubricant.
size=2>...</FONT></DIV><FONT face=Arial size=2>> How do I know if I need rear
brake pads with or without shims (both are<BR>> offered)? Also, why do I
apply the anti-squeal lubricant?<BR>> Thanks,<BR>> Richard<BR>>