Fixing all your keys
AO Silver Member
Join Date: Mar 2001
Location: United Kingdom
County: Tyne and Wear
Rear Brake Update for Graham
I changed the front brake pads as you suggested and with no problems. I said I`d tell you if the rear brakes were any different...
Apart from slightly less room to work in the rear brakes are pretty much the same as the front. The callipers were held on by 16mm bolts instead of the 17mm at the front and I mention this as not all spanner sets will have a 16mm piece in them. As it happens, both sides were exceptionally tight and needed a socket to get them loose anyway.
Two locator screws hold the disc in place and these are the same size as those on the front. One of them was badly rounded and looked difficult to remove with a spanner (they are very easy to round off if over-tight). Instead of trying I used a small metal vice to clamp it and to start the loosening procedure. I find a metal vice is incredibly useful in these situations - they are like mole grips only much better.
The handbrake cable does not need to be removed although it is easy to do this if you wish. Whilst there, why not check that the rubber boots on the end of the cable are OK and stopped up with high temp grease to prevent that frozen handbrake problem in the winter.
The calliper pistons require screwing back to open the calliper up enough for the new pads. This involves turning the piston clockwise and applying pressure at the same time. It was easiest to do this after temporarily reattaching the calliper (without the brake disc). There is a special tool to screw the piston back (£20 from Halfords - thanks Henry) but I didn`t need it. Using a 22mm spanner, or whatever size you have that is sized ok for you, fit the tips of the open end into the cross shape on the end of the piston. Put a rod from the socket set/screwdriver/other spanner/whatever through the ring or other end of the spanner and use it to turn. Quite easy as you only need about 10 turns to get the piston from right out to right in. I did find that the piston will only go in so far and then stop. This was very frustrating but I eventually found that you need to loosen the bleed nipple before it will continue. I guess the backflow return restrictor in the ABS was preventing the fluid getting back up the pipes and there was too much pressure build up. Whatever it was, loosiening the bleed nipple is an essential or you will pull all of your hair out!
The pads are a bit fiddly as the spring on them is quite strong, but nothing too bad.
After a quick bleed of the brake in case of air getting in I just put it all back together. I recommend putting the calliper onto the disc before refitting the disc and calliper properly as its very hard to fit the calliper with new pads after the disc is on.