I'm planning to replace the rear discs on my sister's 2005 Meriva. They's very badly worn down, and I think the pads may actually be down to the metal. I'm not expecting any difficulty, but I was wondering about the difference that the handbrake mechanism makes to the job (I've never owned anything with rear discs before). Does it make the job much more complex than changing front discs, which I've done loads of times?
you will need the appropriate rewind tool, you cannot just press the pistons back in.
I got a rewind tool (one with lots of interchangeable bits) in readiness for the job. Is the rewind tool only needed because of the handbrake mechanism? I'm still not sure why it's necessary, but I'd read that it is.
The pistons are pushed by hydraulic means for the footbrake and mechanical means for the handbrake. The handbrake is pushed by a rod with a 'ratchet' (for want of a better explanation) so that it can get longer as the pads wear (or handbrake travel would increase) To release the 'ratchet' the piston is turned down a coarse thread. On some vehicles the thread is clockwise, some are anti clockwise. Forcing the piston straight back breaks the mechanism.
Thanks a lot - I'm getting some idea of what to expect now. The kit I have has both right and left-hand threads. I suppose I'll try the right-handed one first. Will it become obvious if I am turning it the wrong way? By which I mean, do they turn easily if turned the right way? Or are they always stiff, making it harder to be sure which is the right way to turn it?
If you are going the wrong way the piston will turn a little and then get stiffer, continuing will break things. Yours go clockwise IIRC Do not push the fluid back to the master cylinder, let it out of the bleed nipple.
Okay, thanks. I probably would have just pushed the fluid back, while getting someone to keep an eye on the level; but if letting it out of the bleed nipple is better, I'll do that.
It is better practice in that it removes old fluid rather than shove it back to other places and can avoid problems with abs units, so is worth doing on any car. It also ensures that the bleed nipples get moving every once in a while even if you do not change the fluid (as you should, every two or three years)
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.