Lexs400

the 93LS needed brake pads so I had the local mech replace them. but when putting the calliper back, while putting the last two bolts back on for the assembly, i noticed that the long nut that needs to have the bolts put on had another set of bolt attached inside the calliper. It's as if the caliper is between those two bolts.
while tightening the outer bolt, i noticed that the inner bolt was moving freely right before the mech. tighened the outer last bolt holding the caliper assembly to the body.
I didnt get a chance to ask him, but is the inner bolt supposed to be moving freely with the rod without the outer bolt being tight ? or is the inner long nut supposed to be snug ?
The reason I'm asking this is because the brake is squealing on a light touch of pedal on that side only.
thns for any responses.