Break down diagram

I'm assuming you have Lucas calipers, On that type of caliper you have to depress the piston and at the same time turn it clockwise.
You have to have the bleeder screw open when you do this.
I took a large size C-clamp to clamp down on the piston,then used a giant pair of channel locks to turn the piston.
You have to keep adding more pressure to the clamp while doing this it's somewhat awkward.
You must screw the piston all the way down for the new pads to fit.
Good luck,Gary

Unbolt the caliper from the front fork.Loosen brake fluid reservoir cap on throttle side of handle bar. Remove the outboard pad ( pad on outside of caliper) and use a 6 inch C clamp to depress piston back into caliper housing. Make sure the clamp presses on the old pad and not directly on the piston end as you might press the piston sideways and scar up the cylinder wall, ruining the caliper. Compress piston until it is flush on the inside case of the caliper. Let sit 5 minutes for the pressure to leak down to keep the piston in place. Remove clamp and inboard pad and replace pads. Remount caliper, tighten bolts and pull the brake lever 5 or 6 times. Check brake fluid level with handlebars straight and top off if necessary.
Hope this helps!!

There's a special tool required to compress the rear caliper pistons. You may want to rent the tool. If you look at the piston you'll see one or two notches. The special tool has nipples to fit these notches. The caliper piston will have to be compressed with the tool and the notches will have to be placed in the o'clock and 6 o'clock for the brake pads to slide over the rotor. If you rent the special tool have the renter show you how to use it.

Its possible the brake pads have worn down again, if they are and , obviously , you need to change them. Pay attention to the brake caliper pistons, check that they are not sticking or seized and also the caliper slider. Free off these parts. Hope that helps

for front pads jack and support car remove wheels remove bolts holding calliper [2]remove spring clip pull calliper off remove pads clean housing fit outer pad slowley push calliper piston in using large grips fit inner pad to piston refitcalliper fit bolts refit spring clip can be awkward pump brake pedal until firm check fluid level rear ones are the same but special tool needed to wind calliper pistons back in note make sure brake discs are in good condition first

As the break pads wear it creates a greater volume(capacity) at the caliper piston/s.This causes the fluid in the reseviour to go down.(even though you have no leak) then you top it up & it will again reduce fluid level as the pads wear further.When the pads are replaced you are required to push the pistons back in to accomadate the new(thicker) pads. Before you push the caliper pistons in at brake pad change you will need to drain out some fluid(from the resivour) to stop the resivour from overflowing. This is typical of all hydrolic braking systems on both bikes & cars.Check the pads, If they are wearing this symptom is compleatly normal.

Compressing Rear CalipersIf you open the "bleeder valve" you'll need to bleed the air from your break system. As your breaks wear down, the level in yor break resivor will drop. what works for me is the following: Remove the cap on your resivor and place some shop raggs around the base. With a large "C" clamp push the piston back/into the break caliper (slowly) when the piston is all the in your resivor level will come up. When you complete both sides, you resivor should be near the corect level. Remember that when you put it all back together, your break pedal will go to the floor. Do this a few of times and your break pedal will tighen up. Now you should check the level in the resivor.

Hope this helps and be safe.....

Remove the 2 break bolts that hold the break to the bracket. Remove the pin covers on the side. <2 flat heads> Remove the Alan key pins and old pads will come out. Use a c clamp and a rag to compress the caliper piston. replace break pads pins and pin covers. Re bolt the break to the bracket. pump breaks till stiff. open bleeder. pump twice and close during pump. clean up and enjoy ;D

It sounds like the rear calipers are bad. Raise the rear wheels and see if you can turn the tires. If you can't, open the bleeder. If you still can't replace the caliper. If you can turn the wheel after you open the bleeder, replace the brake hose to that wheel.

When you replace the pads you have to retract the pistons into the bore. As the pads wear they stay extended from the brake caliper. The new thinkness of the pads will not allow the pads the slip over the rotors until you retract the pistons. Your pistons may be the type that have to be turned back into the bore.Good luck.