[Alex_MCS]

Since it was quite sunny today, I decided to change my front discs and pads. I had never done this before, but armed with a Haynes manual and some tools I gave it a go! I've done a quick write up of how I did it, and how to overcome some problems I had, which maybe others will find useful

Disclaimer: Please take care when doing work on your car, I am not trained or responsible for anything that might go wrong!

What you will need:
Locking wheel nut key
7 mm hexagonal socket
16 mm socket
T50 Torx socket
Torque wrench - I got one from Screwfix for £15
Copper grease
New discs and pads - I replaced standard parts with EBC 3GD Turbo Groove Discs and Mintex M1144 pads

1. Loosen the wheel nuts on the wheel you are starting with.
My locking wheel nut key took me a few minutes to find, it was in a polystyrene tool kit wedged near the battery (in the boot in the case of a Cooper S).

2. Jack the car up and support it on axel stands
I found a point about midway between the two jacking points and further under the car to use as a jacking point. I put a piece of mdf on top of the end of the jack so that it did not eat into the car. Once it was high enough I slid a jack stand under the front jacking point (the square lump of plastic which hangs down).

3. Remove the wheel
Undo the bolts holding the wheel on and lift the wheel off. I started with the front left, it's slightly trickier as it has the brake pad wear sensor on it!



When I did this, the wheel seem to be stuck on, I tried kicking, pulling etc to no avail. I did manage to get it off eventually by loosening the lug nuts to just tighter than finger tight and then moving the car slightly forwards and backwards a couple of times.

At this point it is a good idea to loosen the top of your brake fluid reservoir.

4. Prise off the caliper retaining spring
Just use a flat headed screwdriver tucked under the wire to lever it off.

5. Remove the caliper guide bolts
These are two bolts on the back of the caliper which need to be undone. Firstly, prise off the plastic caps with your fingernails as shown:



Then use the 7mm hexagonal socket to undo the bolts. This picture shows the location of the top bolt, there's another one lower down.



6. Remove the caliper
Pull the caliper towards the front of the car, might take a bit of a wiggle but it'll come off. Make sure you support the caliper so that it does not pull on the brake fluid lines. As you can see, I found a new use for an old washing powder box :



7. Remove the brake pads
It should be easy to now remove both of the brake pads. The inner one will pop out of the cylinder if you pull it. If doing the front left, you need to remove the brake pad wear sensor, lever it out with a flat head screwdriver.



As you can see below my pads had a bit of life left in them. However, it is recommended to replace the pads once they reach the same thickness as the backing plate. Warning: DO NOT touch the face of the brake pad (as I'm doing! ). It is ok as I was throwing the pad away, but oils in your fingers can contaminate the pads.



8. Undo the Torx bolt holding the disc



Sounds easy in the haynes manual, in actual fact this was a complete pain to loosen. The bolt was pretty determined to stay put and unhelpfully the disc will rotate whilst you're doing it!

However, help is at hand. I got it off by wedging a flat head screwdrive into a vent in the disc against the caliper mounting bracket as below. This might not be ideal if you want to use the disc again, but it worked for my purposes.



9. Remove the caliper mounting bracket
Use the 16 mm socket to remove the two bolts holding the caliper mounting braket on as shown below. These bolts are quite tight, I had to use a fair amount of force (even with my macho/spindly arms ) and a long wrench to get them off.



10. Remove the disc

The disc should come off easily, if not give it a few knocks with a rubber mallet. You should now have something like the picture below.


Now is a good opportunity to get rid of a bit of brake dust, I cleaned things up a bit using a metal brush. Don't breathe in the dust if you can help it.

11. New discs!
So why am I going to all this effort? Well I figured the money I'd save on labour I'd spend on some improvements I am replacing the stock discs with some shiny new EBC 3GD turbo groove discs:



Read the instructions that come with your discs, but these needed rubbing with white spirit before use to remove a protective layer.

Put the new disc on and tighten the Torx bolt to 27 Nm.

It is not entirely necessary to put this bolt back, it just holds the disc in place in the Mini factory and makes lining the wheel bolts up slightly easier later on. Basically, don't worry too much about replacing it if you had to drill it out.



12. Reattach the caliper mounting bracket
Use the 16 mm socket to reattach the caliper mounting bracket, tighten to 110 Nm. This is quite tight, so a longer wrench is helpful. You can put the new outer pad in place as shown:



13. Compress the piston
The piston will be extended, meaning that you will not be able to fit the caliper back on because there won't be enough space for the new pads (which are thicker than the old ones). So you need to push the piston back in. I used a g-clamp and a small piece of wood as shown below, just tighten the clamp until the piston is compressed completely.



You can then remove the clamp and the piston will stay in place.

14. Fit the inner brake pad
I put a bit of copper grease around the end of the piston as shown below. There's probably a bit too much grease there, I removed some after the photo was taken.


Then just snap the new pad into place. As mentioned earlier, do not touch the friction surface of the pad. Reattach the pad wear sensor.



15. Reattach the caliper
Use the 7 mm hexagon socket to reattach the caliper using the guide bolts, I found it a bit fiddly to line up, but got there eventually. Tighten the bolts to 30 Nm.

I forgot to take a picture of this whilst doing the left side, but here's one of the right - you get the idea!



Clip the retaining wire back in place, if it's a bit of a pain, use a screwdriver to lever it back in place.

16. Reattach the wheel
Line up the holes and screw the bolts lightly. Jack the car up a bit to free the axle stand and then lower the car back down. The wheel bolts should then be tightened to 120 Nm.



Don't forget to put the lid back on the brake fluid reservoir!

All done! (except the other side ) Took me a good few hours to do the left side, but only 45 minutes to do the right. It's much easier when you've done it before. Use the same method for the right side, just ignore the bits about the pad wear sensor as there isn't one!

Improvements/suggestions on the method I used are welcome!



You can discuss this DIY Guide in the original thread here: 1st Gen - How to Change Front Discs and Pads