Okay, before I begin, this is how I rebuilt my rear calipers and may not be exactly the same on all models. Don't do any work like this if you are unsure what to do or are in a rush - seek professional help! Do one side at a time so you have one side for reference, get everything ready in advance and take your time! Tip: As you go, lay out the parts you take off in the order you removed them so it's easy to see the steps for the rebuild.
This guide of for a full rebuild - you may only want to replace the piston and dust seal in which case you won't need steps 7 & 8 you'll stop and rebuild around step 10. I will do this in 2 parts, strip first and rebuild later.
Tools:
Large flat blade screwdriver
Small slat blade screwdriver
Bull nose pliers
Internal circlip remover (long nose)
17mm spanner (or socket and ratchet)
Wire brush
Brake cleaner
Rags
Water
Step 1. Identify which rear caliper you have - you can do this on or off the car. I did this by lifting off the caliper so I could measure the piston diameter and this helped me identify which rebuild kit to buy. There are several from what I've found, mine are 30mm piston but some seem to be 34mm pistons. Get the correct kit before stripping everything down! There are several options - you get a caliper kit or a caliper and carrier kit. You can even sometimes get a new pistons with all the new internals done, I've opted for a caliper rebuild kit as I have brand new carriers with pins and rubbers.
Step 2. Order the kit from your favorite retailer and wait for the postman......
Step 3. Layout everything and make sure before you begin to strip the caliper you have everything you need
Step 4. Once you have the kit and have a few hours to spare - Remove the caliper (and carrier if you are doing that too) from the car - I'll assume that you can remove the handbrake cable, brake hose and 2 retaining bolts
Step 5. Check again, once you start this it's not easy to go back!
I have 2 pistons, 2 caliper rebuild sets and (by mistake) the carrier rebuild sets
Step 6. Clean up the caliper - you can do this a number of ways but I suggest plugging the brake hose fitting hole (little red cap in the pictures above) and wire brush up the caliper all around. Doing this now with all the seals in place you don't have to worry about getting dirt inside the caliper itself as the seals are still intact. I cleaned mine after the strip down and then had the pleasure of cleaning out the internals afterwards
Step 7. Now the fun begins - hold the caliper securely and release the handbrake spring. It's not under a lot of tension so it doesn't want to fly across room!
Step 8. Remove the handbrake nut - there is a lock washer underneath so be careful not to lose it. This will then let you remove the handbrake lever arm.
Step 9. Turn the caliper around so you can remove the piston. The piston unscrews from the body of the caliper. I used the large flat blade screw driver for this, although there are proper tools for this job...
Note that when you released the piston, you may still have some brake fluid in there - it will want to go everywhere. You can neutralize brake fluid with water (It will strip paint if left otherwise!)
Step 10. Remove the dust seal - mine was broken but it came out easily with the small screwdriver
Step 11. Remove piston seal part way down the caliper barrel. If you don’t get this out then you can't get the next parts out in step 14
Step 12. Remove internal circlip holding the self adjusting handbrake mechanism in place. Not easy to photograph but if you look down in the caliper you'll see the circlip that holds everything else in place. It took a bit of fiddling but wasn't impossible
Step 13. Remove the top hat, spring, washer and bearing. It will fall out now the circlip is removed. Note the order they came out in! Tip- if you have a bolt and some washers you can assemble the bits in order and store them until needed
Step 14. Remove the spindle. This will just pull out, leaving the last 2 pieces of the handbrake mechanism behind. If you're lucky, they may come out with the spindle, otherwise you can turn the caliper over and give it a light tap to remove. Be careful not to lose the pin underneath the piston
Step 15. Remove the handbrake pin - This was held in place by the parts removed in step 14, so will now pull straight out of the caliper. Note which way round the hole in the pin faces!
Okay, I'll stop here for now and finish when I start to replace all the seals. You now have a stripped caliper, ready for rebuild or painting. This isn't the easiest of jobs and I can understand why companies charge so much to do this work!