What size wrench do I need to use to remove the brake caliper?

The hex size to remove the brake caliper on a 2000 Jeep Cherokee is typically 17mm or 11/16 inches.
It's important to use the correct size socket or wrench to remove the brake caliper, as using the wrong size can cause damage to the caliper and/or the brake system.
When removing the brake caliper, it's important to take the proper precautions to prevent damage to the brake system and ensure safe operation of the vehicle. Always support the caliper with a wire or a bungee cord to prevent it from hanging by the brake hose.
Additionally, it's recommended that you work on one brake at a time, so that you have a reference point for the position of the caliper and the brake pads.

12 mm ,14,mm wrench or socket that to remove the caliper 17 mm wrench or socket for the bolt holding the brake pad braket

Two bolts hold the capliper solid in the caliper bracket that is fitted on the wheel hub. Just find the right size wrench for those two bolts (possibly 10 mm), remove them, and the caliper is free except for the brake hose leading to it. If removing completely from the car, remove the brake line at the union fitting, then unscrew it from the caliper.

Allen wrench size to remove brake caliper on my 2008 mercury mariner

For front brake pads replacement you only need usually wrench set, inclusive 7 mm allen key also. But for rear brake pads replacement you need obligatory a special caliper piston pressing tool, in order to press back rear caliper piston with parking brake automatic adjustment!!!
Instructions for front brake pads replacement.
For change front brake pads you must raise vehicle, remove wheels, extract the retaining spring of the caliper, and remove the caliper as follow:
1. Do not disconnect the brake hose from the caliper, and do not allow the caliper to hang by the brake hose!
2. Remove top and bottom caps (on back side of the caliper) for access to guide pins, then unbolt and remove them from the brake carrier. Remove the caliper.
3. Now you must thoroughly clean the brake calipers (free of grease).
4. Remove outer brake pad from brake carrier.
5. Pull inner brake pad out of brake caliper piston.
6. Check up the brake fluid level on the reservor, and emptying if neccessary!
7. Push piston back into brake caliper housing.
8. Install inner brake pad (with expanding spring) in brake caliper piston. (Arrow marked on pad - if exist, must point in direction of brake disc rotation when vehicle is moving forward).
9. Install outer brake pad into brake carrier.
10. Bolt brake caliper housing to brake carrier using two guide pins. Tightening torque is 25 Nm.
11. Install both caps.
12. Insert retaining spring into brake caliper housing.
Important note: Depress the brake pedal firmly several times while the car is stationary so that the brake pads adjust to their normal operating positions!!!
Check brake fluid level and top up as neccessary!

You will need a 7mm allen to remove the front brake caliper.

i just changed my front rotors and pads on my 2001 escape, 6 cylinder. everyone was wrong on the wrench sizes, including the idiots at my local ford dealer. to get the brake calipers off I needed a 7mm hex bit. to get the caliper bracket off I needed an 18mm socket, it was a very easy job but check your wrench sizes first, it seems that every year and model uses different sizes.

Usually about 9/16. It should be SAE not metric, but if the standard is slightly loose, then you may be best off switching to metric socket.
You can go to autozone.com and register for full free online repair manual for your car. With everything you could need.

Calipers definitely will need to be removed. The size wrench will depend on your vehicle.

So this is what it takes to replace rear brake rotors on a 2003 Mercedes E320;
1) open the bonnet (hood) of the car and loosen/remove the cap off of the brake fluid resevior.
2) remove outer spring clamp from brake assembly (it clips in to the iner edge of the holes of the caliper).
3)using a 7 MM allen wrench, remove the brake caliper.
4) using 18 MM box wrench, remove the caliper housing assembly off of the wheel hub.
5) using a star wrench, unscrew the rotor locking screw from the rotor
6) squirt some liquid wrench on the rotor hub and knock the rotor with a hammer to work the liquid wrench in.
7) using the same hammer, knock the rotor off the hub.
8) using a metal file, lightly file old residue off of the hub and place the new rotor on the hub.
9) set the hub by screwing in the lug nuts and then screw in the hub locking screw using the star wrench, then remove the lug nuts.
10) reinstall the caliper housing assembly onto the wheel hub using the 18 MM box wrench.
11) push back the brake claiper piston to its home position and install the inner brake pad (the one with the snap clips)
12) insert the outer brake pad in the claper housing assembly.
13) slide on the caliper housing with the inner brake pad in place (over the outer brake pad) and screw in the caliper screw rods using the 7 MM allen wrench
14) on the right wheel brakes, DO NOT FORGET to slide in the brake sensor (the one with the black connector) and connect it to the connector on the caliper housing.
15) be sure to reinsert the spring clamp onto the outer brake assembly to set the assembly squarely onto the wheel (there should be no wiggle in the brake assembly after the spring clamps are installed).
16) finally mount the wheels.
17) you can bleed the brakes at this point to release any trapped air (which is unlikely) but be sure to pump the brakes after starting the car BUT BEFORE MOVING IT to re-preassurize the brake system before driving the car.
17) ONE WEEK LATER - recheck brake assembly to ensure all is okay and brake fluid.

This proposed solution is for a 2003 Mercedes Benz E320 and NOT a 2005 model as stated by the limited option selection provided by FIXYA.com when initially describing the problem.