Rear brake pad caliper pin is stuck. allen wrench is stripping bolt.

Allen wrenches usually come in a set, try 3/8.

Start with a suitable container placed under the rear caliper brake line banjo fitting to catch any brake fluid that may leak out. NEVER reuse brake fluid. Use only Dot 5 Brake Fluid in a 2006 XLH motorcycle. NEXT remove the banjo bolt and both washers to detach the rear brake line from the brake caliper and throw away the washers, remove the pad pin plug, unscrew and remove the brake pad pin, remove the brake pads, unscrew and remove the caliper bolt pin, slide the brake caliper on the rear bolt pin away from the brake disc as far as possible. THEN with an open end wrench unscrew the mounting bracket bolt pin from the caliper mounting bracket and lift the brake brake caliper straight up and away from the brake disc and the caliper bracket.

LUBRICATING THE REAR CALIPER BOLT PINS AND BOOTS
FIRST apply about 0.4 g of G40M BRAKE GREASE inside the caliper bushing boot and the caliper pin boot and inside the boot lip to prevent sticking between the boots and the bolt pins and insert the mounting bracket bolt pin into the caliper bushing boot.

INSTALLATION
Before installing the caliper ensure that the retainer bracket is properly installed on the mounting bracket, then apply a small amount of LOCTITE 272 THREADLOCKER to the threads of the mounting bracket bolt pin, place the rear caliper assembly onto the mounting bracket and using an open end wrench thread the mounting bracket bolt pin into the caliper mounting bracket and tighten it to 87-130 in-lbs (9.8-14.7 Nm). THEN apply a small amount of LOCTITE 272 THREADLOCKER to the threads of the caliper bolt pin, slide the caliper bolt pin through the front mounting hole in the caliper, carefully insert the bolt pin shaft into the caliper pin boot in the mounting bracket and screw the bolt pin into caliper and tighten it to 15-18 ft-lbs (20.4-24.6 Nm).
NOTE that the brake caliper housing has a positive stop for banjo fitting and so when tightening the banjo bolt into the brake caliper you will need to rotate the banjo fitting clockwise until it contacts the positive stop.
THEN position a new washer onto each side of the hydraulic brake line banjo fitting, insert the banjo bolt through the washers and fitting into the caliper housing and tighten it to 20-25 ft-lbs (27.1-33.9 Nm). THEN insert the brake pads into the caliper with the friction material on the pad towards the brake disc and with the curved portion of the pad fitting into the recessed area of the caliper and the brake pad front mounting tab fitting into its slot in the caliper mounting bracket. THEN press the brake pads tightly up and against the brake pad spring and install the brake pad pin but if the pin does not easily fit in ensure that you are suing the correct brake pads and not two identical pads, that the brake pad spring is oriented correctly, that the brake pad front mounting tabs are properly seated in the slots in the mounting bracket and that the brake pads are correctly pushed tight up against the brake pad spring BEFORE the brake pad pin is installed. AND THEN tighten the brake pad pin to 131-173 in-lbs (14.8-19.6 Nm). THEN install the brake pad pin plug and tighten it to 18-25 in-lbs (2.0-2.9 Nm). THEN with the rear brake master cylinder reservoir in a level position verify the brake fluid level in the reservoir. If necessary and with the bike upright and not resting on its jiffy stand remove the rear brake master cylinder reservoir cap and add sufficient new D.O.T. 5 BRAKE FLUID to the reservoir to cause the fluid to reach the upper fluid level mark, but do not exceed this mark. THEN verify the proper operation of the master cylinder relief port because a plugged or otherwise blocked relief port could cause the brakes to drag or stick on. Do this by pressing against the rear brake caliper to push the caliper piston back into its bore and push brake fluid back through the master cylinder and into the reservoir. THEN pump the brake pedal until the caliper piston pushes the brake pads out against the brake disc and firm pressure is returned to the brake system.THEN turn ignition switch ON and pump the brake pedal to verify correct operation of the brake lamp and test ride the motorcycle at low speed to safely test the brake system. If the brakes feel at all soft or spongy, bleed the system until you get a firm, hard pedal and avoid making hard stops for the first 100 miles (160 km) to allow the new pads to become conditioned to the brake disc.


Replace brake pads at any time the brake pad friction material on either the front or rear caliper is worn to 0.04 in. (1.02 mm) or less above the backing plate and always replace both pads in a caliper as a set.

The minimum brake disc thickness is stamped on the side of the disc and it must be replaced if and when it is badly scored or worn past the minimum thickness. Maximum brake disc lateral runout and warpage is 0.008 in. (0.2 mm) when measured near the outside diameter.

Just follow this instructions:

1 Unbolt the brake caliper from the front fork or rear swingarm, using a socket wrench. Use a 14-mm hex socket to unscrew the front caliper bolts, and a 6-mm Allen socket for the rear caliper.
2 Slide the caliper off the brake rotor. Suspend the caliper from the handlebars or frame, if needed, using a bungee cord.
3 Pull the hair clip pin out of the brake pad's retaining pin on the outside face of the caliper using a pair of needle-nose pliers. Push the retaining pin out of the back of the caliper with your finger.
4 Pull the brake pads and their spring clip out of the caliper. Retain the spring clip, and discard the brake pads.
5 Reinstall the brake calipers, following the reverse method of removal.

I hope this will help you. thanks

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!

For front brake pads replacement you need only 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!!!
For front brake pads. You should buy the brake pads (with wear sensor). 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: 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 if neccessary!!!

For front brake pads replacement you need only 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!!!
For front brake pads. First you must verify yours front brake disc diameter: 280 mm or 288 mm. After that you can buy the brake pads (with wear sensor). 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: 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 if neccessary!!!

For front brake pads replacement you need only 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!!! For front brake pads. First you must verify yours front brake disc diameter: 280 mm or 288 mm. (On my car y have 288 mm). After that you can buy the brake pads (with wear sensor). 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: 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 if neccessary!!!

For a wrench or for the acctual bolt size.
To remove front pads..you need 8mm allen socket to pull the caliper guide pins, then 17 or 18mm..To remove rear pads...you need 13mm socket for lock bolt on guide pins and 15mm open end wrench (thin section to hold guide pin while you remove lock bolts..I ground down a spare wrench). You DO NOT have to remove rear carriers to change rotors..just remove lock screw and angle rotor out. The B5 Passats don't have the electronic parking brake so you don't need VAG Com to change pads.
Installation tips:
Clean and regrease the guide pins with "synthetic caliper grease"
Rear lock bolts come with preapplied thread locker and "are not to be reused"..I just wire brush the threads and use some Loctite Blue on em. I smear just a little antisieze on the inside bore of the rotors and on the lock screw threads to prevent corrosion and make next rotor change ez. Torques:
Front caliper guide pins:18 ft lb
Front carrier bolts: 89 ft lb
Rear guide pin lock bolts:26 ft lb
Wheel lugs: 89 ft lb

There are 2 bolts on the "inside" on the caliper towards the bottom they use an allen wrench socket.

the allen wrench bolts should be the correct bolts to remove brake caliper to allow access to pads.


hint: there will be only two bolts to remove and they will be the same maybe different lengths