What size Allen wrench is needed to replace front brakes on 07 navigator?

All vehicles have many Allen screws on them. The only sensible and economical thing to do is buy 2 sets of Allen keys, usually 1/32 up to 3/8 in SAE and 1-10mm in metric. They only cost about $ 12 per set and will save you a lot of hassle if working regularly on cars.