This article provides a step-by-step installation of the Subaru 4 pot caliper rebuild.
The following parts are required:
- Caliper seal kit: 26297FA050
Step 1: Have calipers removed from vehicle as is, drain fluid and obtain a well lit work area with chair…you’ll need it as it takes several hours to clean, inspect, and reseal the calipers.
Step 2: Wipe the calipers down removing any loose dirt, brake dust, and fluid.
Step 3: Simply remove the piston clips and dust boots, use a flat head screwdriver and carefully pry up. You may find it necessary to pump the pistons out of the caliper or use compressed air.
Step 4: Wipe down all pistons and very carefully pry up all the pistons with large flat head screwdrivers. This is what the caliper should look like right before piston removal. Note: one boot has been left on for picture illustration below.
Step 5: Your caliper should look like this:
Step 6: Remove all inner piston seals with a tartar scraper/puller:
Step 7: You should carefully remove these by pulling them up and out to the inner area of the cylinder like so:
Step 8: Wipe clean (use a small amount of brake parts cleaner on a clean cotton rag) the entire piston cylinder area, this may take a while, be meticulous. Do not use anything abrasive. Your pistons should look like this if they are not scarred or damaged. To further clean the pistons, use steel wool for surface rust or to polish them. Before re-installation clean the pistons with compressed air. The cylinders cleaned are shown below as well:
Step 9: A coat of brake fluid should be applied to the seal, piston and the cylinder surface before the assembly.
Step 10: Carefully stretch the new outer dust boots into the pistons recessed channel (make sure it is seated properly). The grease is just to be used on the lip surface of boot where it contacts the piston. The piston on the left is the correct way to set them up back into the caliper housing. The right piston in this picture below is an illustration just showing that the dust boot is correctly installed and seated.
Step 11: Here you will see the pistons reinserted with the boots previously installed back into the caliper. DO NOT GET GREASE ON ANY AREA OF THE OUTER DUST BOOT.
Step 12: Push the pistons with equal force (can’t stress this enough) into caliper until the dust boot is close enough to the retaining clip area to seat properly (you do NOT need to push the pistons completely into the caliper housing so that it bottoms out), this was right before I worked my finger pushing around the boot to seat it to the caliper:
Step 13: Install the new dust boot clips by laying one side of the opened end onto the boot, hold it with your fingers (or have an assistant hold it for you), then work the remainder of the clip around the caliper lip to seat it properly and if you do it at the correct angle you can let go of the end and it should snap and seat itself onto the lip of the caliper, verify that the entire clip is seated properly and not pinching the rubber boot.
Final Assembly: Your calipers should look like so:
Information Source - NASIOC forum thread, Subaru 4 pot Rebuild w/pics