- Jack stands
- Coathanger (Used to hang calipers)
- Socket Set
- G Clamp *or* Disk brake Spreader
- Brake Cleaner (Will probably only use 1 can, but have 2 on stand by)
- Brake Bleeding kit (or well sized tubing)
Crack the wheel nuts while the car is still on the ground.
Jack the car up, place jackstands on both sides. Never work on a car solely supported by a jack! If you have some old rims lying around, it's probably good insurance to place them just behind the wheel arches under the car. This way if the car falls, you won't get crushed, and less damage will occur to car..
Once the car is up (and steady), remove the wheel nuts and wheels.
The next step involves removing the caliper bolts so the caliper can be removed from the wheel hub. On my VS Commodore, there are two 19mm bolts behind the caliper. When I first changed my cars brakes, these came off with a bit of force and a normal wrench, however with my friends VS we needed a breaker bar just to get them to budge.
Before unbolting the caliper, you will need to fashion a hanger using the coat hanger. Grab a pair of pliers and cut the hanger into a standard s style hook, around 20cm's long.
With your handy hanger at your side, you can continue unbolting the caliper. When the caliper bolts are off, you must be sure not to let the caliper hang by the brake fluid hose. This *could* cause damage to the hose and give you a whole lot more to fix.. Use the hanger to hang the caliper from the springs, I usually use the top/second coil and hook the other end of the hanger to the bottom of the caliper, letting it hand upside down and not stressing the hose.
With the caliper off, you can perform any maintenance on the Disk Brake which you are planning to carry out. The disk should simply slide off, unless it has rusted into place. If the disk doesn't come off, cover it in WD-40, let it soak in for a while, and tap it from behind with a rubber mallet. If you are reusing the disk, be careful not to do any damage.
- Need to confirm that WD-40 won't ruin a disk**
The next step is ensuring that the caliper will fit over the disk once the new pads have been installed. This usually always requires pushing the piston on the brake caliper further open.
This is where a G Clamp or Brake Spreader comes in handy. Place a piece of tubing securely over the bleed valve on the caliper, place the clamp in place to be able to push the piston further open. It may be easier/safer to leave the old pad in the caliper to protect it. Open the bleed valve and tighten the clamp to compress the piston. This will cause fluid to flow from the bleed valve. When the piston is fully open, close the bleed valve and remove the clamp.
It is important to ensure that the tubing remains on the bleed valve, this way if the valve tries to suck in, it will get brake fluid and not air.
Now you can clip the new disk pads into place. It's easiest if you have a look before taking the old ones out. For my pads, there is an edge on each side of the caliper, and a spring which seats into the bottom of the caliper. It's easier to insert the brakes at a 30degree or so angle, ensure the spring is seated properly, and ensure the edges are under properly. You can then push the pad across so it lines up properly.
With the new/machined/original rotor back in place, and the new pads in, it's time to put it all back together!
Before sliding the caliper back into place, spray the pads liberally with brake cleaner and allow to dry. Bolt the caliper onto the hub. **I have heard it is a good idea to loctite these bolts, and will investigate this for future brake jobs.**
This is where the brake cleaner comes into play. You want to ensure to liberally coat all of the braking surfaces with brake cleaner. I usually rotate the disk and spray cleaner onto the front/back of the disk. This helps remove any contamination and ensures good braking.
4: Fill brake fluid, pump brake pedal to pressure, apply pressure to pedal, loosen bleed valve, let pedal run to floor. tighten valve, pump up pressure.. wash rinse repeat for a while..
We did this for both bleed valves right? about 7 times each?
- pump up pressure - hold pressure on the pedal - release bleed valve - pedal will go to floor - bleed valve MUST be tightened BEFORE foot is lifted - otherwise air will be sucked in through the bleed valve - complete opposite of what we want to do :) - repeat about 7 times or so.. (Never re-use the fluid that comes out! must not go back into reservoir) - usually you use a clear pipe on the bleeder.. longer is better because easy to keep clean. being clear you can see bubbles of air in it... to basically you keep doing the bleed process until you see no more bubbles :)
- do this for each bleed valve - so yep 2 if you are only doing the front brakes. best practice is to start with the valve the furthest from the pedal.. which in australia is usually the left one hehe. then once that is clear, do the right. - sometimes helps to get brake fluid that have different colours.. so you can actually see when you have flushed thru the whole line... they dont usually advertise the colours and it is totally up to luck lol.. i usually get lucky with my brake fluid choice :P
5: Put everything back together, take it for a drive, brake moderate/hard but not to a stop to wear in pads... - yeah just at first take it easy and make sure that when you brake the steering is not pulling to one side or the other (or more-so than it was before doing the brakes). car should track pretty much straight on a flat surface provided wheels are alligned well.. then yeah give them some stress but do not come to a complete stop after a heavy brake.. keep moving as you dont want them to overheat :)