Brake Pad Replacement


Tools Required 14mm socket 19mm socket 1/2" Torque Wrench Flat-blade screw driver Jack stand(s) Jack (preferably a floor jack) Bungee cord or string (for holding the caliper out of the way) Optional Tools Disc brake piston compression tool Materials Brake pads (duh!) Silicon brake grease (i.e. Subaru 26298AC00 (Molykote AS880N), or Volvo 1161325-4 PTFE Silicon Grease ) Non-Chlorinated Brake Cleaner (optional) Loctite (optional Loctite 242 (Blue)) Shop towels or rags Mechanic's latex gloves (just cause you work on your car doesn't mean you have to look like a grease monkey for the next few days)
Instructions (click any picture for a full resolution image)
Start by jacking the wheel that you are going to work on up and off the ground. But before you get too far, only raise the wheel until just before it looses contact with the ground. Now is the time to loosen the wheel lug nuts. You just need to break the lug nuts free, so you can almost turn them by hand (without the wrench). Do not remove them yet. Now finishing jacking the wheel all the way off the ground. Lugs nuts should always be removed opposite one another. You should never remove them 'round-the-clock', as this can lead to breaking off a stud. The picture shows the correct order to loosen, and tighten lug nuts.	Instructions to be provided later...
Instructions to be provided later...	Place a jack stand at suitable location, and lower the car until the jack stand is supporting the weight. Now you can finish removing the lug nuts, and remove the wheel
	With the caliper now in plan view, you need to locate the bottom caliper bolt. Subaru refers to this as the lower guide pin. Using the 14mm socket/wrench remove this bolt. You do not need to remove any other bolts) other than this one to access the brake pads.
You can now rotate the floating part of the caliper upwards and off of the rotor (the pads should remain in place since they are secured with a number of retaining and anti-rattle clips).
	Secure the caliper out of the way. I prefer a bungee cord that is attaches to the spring.
Now that the caliper is out of the way, you can remove the inner and out brake pads. The flat blade screw driver will help you slowly pry the pads out. You should slide the pads off the rotor towards the outside edge of the rotor. This is the easiest way direction that will avoid damaging your retaining clips.
	With the pads out, inspect them carefully. You will notice that a stainless steel shim is attached to the back side of each pad. Actually there are two of these shims. You need to remove them (without braking or bending them).
Now clean the shims (non-chlorinated brake cleaner is excellent for this). They don't have to be spotless, but should not have any large deposits on them that would interfere with them laying and stacking flat
	Next if there is a build up of brake dust on the piston boots (the rubber bellows that connects the piston cups to the caliper body), then you should gently remove the brake dust. A small brush, or shop towel will do. I prefer not to use any chemicals since they can do long term damage to these boots.
Next you need to clean the contact surface of the piston. For this I use a paper towel sprayed with brake cleaner, making sure to minimize contact with the rubber bellows we just cleaned. The piston surface should be free from all deposits. If it is not your brakes will probably squeal when applied
	Now you need to depress the piston(s) back into the caliper housing, but FIRST, pop the hood, and remove the filler cap to the brake master cylinder, and place a towel around the opening to catch any overflow. We are doing this because we are going to be forcing the fluid out of the brake slave cylinders, and back into the maser cylinder. As we so this brake fluid will typically overflow out of the reservoir, and can remove your paint as well as a number of the better paint removers out there.
Now you are ready to compress the pistons back into the calipers. If you have a piston compression tool, then it will make the job easier. For the front dual piston caliper, I always use one of the old pads to spread the load out. You are trying not to push the pistons back into their housing lob-sided. If you are not carefully and just force the piston back in by only applying pressure to one side you could score the cylinder, or piston, and then have a leaking caliper. Depending on which part is damaged you will have to at a minimum rebuild the caliper, or worse replace it (not bad if you are planning on a big brake kit, but otherwise just make sure you slowly and carefully press the piston all the way back into the caliper. If you do not have a pad compression tool for the front calipers, then make sure to use one of the old pads to distribute the load while you are using a pry bar, or what ever to press the pistons back in. In is important to press both pistons back together, otherwise you it will be like playing one of those Bop the weasels games, as you push one piston back in, the other will slide out, and you can go back and forth between pistons forever
	With your new pads, it is time to make the shim sandwich. On a dust free surface, apply a thin layer of silicon brake grease to all sides of the shims. The dark, slotted shim goes first. Just make sure that while re-assembling the shims that the grease does not find its way onto the front side (or business end) of the pads. Both the shims have tabs that should line up with pad, and secure them to it, via friction.
Now you can install the pad and shim assembly against the rotor. Installing them in the opposite direction that you took them out (from the outside edge of the rotor, and towards the center of the rotor). You may have to fool with the pads a little and wiggle them into position, past the anti-rattle clips that will hold them in place when they are in position
	You can now slowly lower the caliper body that was up and out of the way. Note that as with all floating calipers the caliper body is allowed to slide inboard and outboard on the guide pins. Since you are replacing worn pads, the caliper should be slide in and out to line up over the pads, and finally over the pads. If you cannot lower the caliper over the pads, it is typically because the pistons are still protruding too far out of the caliper body, and are catching on the edge of the pads. You should never have to force the caliper back into position! If this is the case, then just make sure the pistons are compressed all the way into the caliper body and try again. It should eventually slide right back into position
Now just re-install the lower caliper bolt. It should be tighten to 37N-m of torque using a torque wrench. Since it would be a really bad thing if this bolt were to come loose, I always us a drop or two of Loctite.
	Reattach the wheel, and tighten the lugs nuts as tight as possible (but no more than 65N-m). The rear wheels can actually be fully tighten with the wheel off the ground due to the differential, but the front wheels will rotate while tighten the lug nuts.
Now lower the wheel again to the point where it just starts to touch the ground. You should now be able to finish tightening the lug nuts to 65N-m. If you full weight of the car is on the wheel before the lug nuts are fully tighten you run the risk of either stripping a lug nut, or mount the wheel off-center, which will can lead to it falling off later on the freeway.
That's it. Now just repeat for the remaining three brakes. While it may sound like a lot, it is actually quite easy, and should only take about an hour to do all four wheels.
The real concern and why these instructions are so long is that you are going to be working on the main component of you car that stops it. Any failure in this area is going to result in an accident, guaranteed! Brakes should not be fooled around with. They should be treated with the respect that you place on your own life