Evening all

Did my brakes today. Easy job. Pads were quite worn and discs very rusty so I decided to replace all discs and all pads in one sitting. Here's a write up and a few tips. Hope useful to others.

Firstly, nothing complicated about this job, if you've done brakes before its a doddle. Tools and stuff I used:

Trolley jack
Axle stand
Breaker bar (I used an extendable ratchet)
23mm impact socket
17mm socket
15mm socket
M7 allen bit long
M7 allen socket short
10mm ratcheting spanner (or basic open end will do just slower)
9mm flare spanner
Flat head screw driver
Pliers
One-way brake bleeder valve/tube
Small pry bar
Calliper piston spreader
Bungee cord or wire
Impact gun
Brake fluid (which you may or may not need)
Pads
Discs
Copper grease
Grease

REARS:

Open bonnet and remove fluid bottle cap and see whats what in terms of level of fluid. Jack up the car. Axle stand in for safety. 23mm impact socket and gun to remove wheel. Remove anti-rattle clip by prising out the ends from the face of the calliper. Hole with pliers to avoid it pinging off into your face! Attach brake bleeder to nipple and crack open using 9mm flare wrench (avoid using standard wrenches they can easily round off the nipple bolt and then you're in a world of woe). Start pushing piston in using screw driver to lever on pad then get the pry bar in and push it back as far as you can. Tighten nipple. Remove slide bolt dust covers. Use M7 short allen socket and ratchet to remove slide bolts. Pull off calliper and suspend on bungee. Pull pad from calliper and the other from calliper bracket and discard. Use spreader to push back the piston the last few millimetres. Using 15mm socket remove calliper bracket. Bolts can be very stiff so use breaker bar if necessary. Give it a quick whack on the ground to remove any loose rust. Pull disc off (handbrake off!!). Bit of copper grease on mating face of new disc and slide this on over studs. Refit caliper bracket, Bit of copper grease on contact points on pads. Clip inner pad into calliper. Fit outer pad into calliper bracket. Slide over the calliper and give it a wiggle to position it. Bit of grease to lube the slide bolts (lightly sand first of pitted or corroded). Tighten into place. Refit dust covers. Refit clip (see comments at end!). Refit wheel and repeat the other side.

FRONTS:

Few differences here. You cant use a ratchet on the slide bolt (at least one of them anyway) due to position of the brake hose. I used a long M7 allen bit - the type that you would usually use a socket-holder with and a ratchet. Slip over a 10mm ratcheting wrench and push into the end of the bolt. Remove slide pins in the normal way - I liked this set up so used it for the other slide pin as well since it was in my hand already!!

Calliper bracket bolts are 17mm. Mine were super-tight, too tight in my view.

Both my discs were missing their retaining screws but since this is a stud/nut arrangement rather than a bolt only arrangement I wasn't too bothered

You can turn the steering to get better access at the front

Refitting the retainer - slightly different in that the long part goes behind two flanges on the calliper unlike the rear where it sits in front

Once all corners complete check brake fluid (check after each corner as well to make sure it doesnt spill over). Refit cap securely.

GENERALLY

I don't like pushing fluid up through the system. The worst fluid is by the calliper and in the calliper. You can upset the ABS system on some cars. You also risk inverting master cylinder seals. Yes I know some will say its not necessary to release bleed nipple when retracting calliper pistons but I buggered up a 5 series BMW last year doing what I had done for 20 years and just forcing the piston back so I don't risk it now. Plus its much easier and your fluid level should remain about the same given you are fitting new fatter pads. Ratchet type spreader is a must-have cheap tool for those last few mm of piston travel. I was happy to allow that tiny amount of fluid to be pushed back.

Flare wrenches are for use on brake unions and nipples. Normal spanners are not. I've rounded nipples off before rushing and just picking up the nearest 10 or 8 (or this case 9 ...)mm wrenches and then you've just made the job that much longer sorting it out.

Keep calm trying to refit the anti-rattle clips!! There must be a technique here but I don't know it!! Very frustrating. Try to avoid exploding into a rage about how BMW ones are so much easier to refit!!!

You'll get to use your 15mm socket that you've probably never used before (especially if you work on German stuff!!). Also a 9mm bleed nipple?! Another first for me.

ANYTHING I HAVE MISSED PLEASE ADD!

All the best
Sam.

 

Here's some pics of new rears. Forgot to take photos of fronts. Discs are Delphi. Weirdly my rear end rattle (see separate thread on that) has disappeared!! You can just see my new (1 month old) rear shocks in first pic. Last pic is one of the old rusty discs.