Type and year of car would help.
A 3/8" Allen wrench will remove that bolt on the front caliper.
7 mm Allen wrench
It takes a 3/8" allen wrench to r & r that caliper bolt.
They changed them again! Now you don't use an Allen wrench or a star to get those caliper bolts out. You have to squeeze a metal retaining frame that encompasses a rubber bolt. While squeezing the metal pieces so that the edge clears the caliper bolt hole, you hammer the dang thing! Then get out some kind of long rod that fits in the bolt hole and keep hammering until the caliper bolt comes out! Then carry on with business as usual.
To replace brake pads and rotor: Unbolt wheel, unbolt caliper, remove caliper, unbolt caliper bracket, remove rotor, replace rotor, bolt up bracket, compress caliper, replace pads, replace caliper, bolt up caliper, bolt up wheel, repeat whole thing on other side...
You need a torx type socket. If you use an Allen wrench...you will strip out the inside of the bolt.
This is how you will replace the front brakes on a 2000 Saturn Sc first you will jack the car up with jack stands. You will then remove the front wheels, next remove the upper caliper to mount bolt only. Then you will pivot the caliper downward to access the pads, you will remove the old pads and install the new pads. You will use a 'C' clamp and a old pad to bottom the caliper piston and you will pivot the caliper back into place and re-install the bolt.
I did my jetta brakes many times, but I dont recall the bolt lengths. Ensure you have adequate engagement into nut. The dealer can supply you with the proper bolt for about 4 bucks.
You need a 15 mm wrench.
THERE ARE TWO BOLTS ON EACH SIDE OF THE CALIPER REMOVE THOSE AND PULL THE CALIPER OFF
It is a special bolt/pin that allows the disc brake caliper to float. There is usually two per caliper.
18mm