Toiletbrush

I am planning to do a full F/R caliper rebuild in a couple of days after the kits arrive in the mail. This is going to be part of a project involving a swap to SS lines, Project Mu HC+ pads and possibly a caliper paint job. I have been searching for a site that may have a walkthrough on the rebuild procedure to make the process easier. Just trying to do the homework before I jump into this project. Any information would help. Thanks!

Toiletbrush

I am going to answer my own question for the sake of those who may be needing an answer in the future. I found out the procedure by doing it, but I can say that it would have gone faster had I knew what I was getting into beforehand!

1) Remove the caliper from the car and remove the pads from the caliper.

2) Remove the metal c-ring from around one of the outer piston boots.

3) Remove the outer piston boot.

4) Use two screwdrivers to gently pry the piston out of the caliper.

5) After the piston is removed, use a scribe or dental pick to remove the inner seal from inside the caliper cylinder.

6) Repeat for the other three pistons on the caliper.

7) Thoroughly clean the pistons and the entire caliper using brake cleaner and a brush (if necessary).

8) Remove any traces of rust from the outside of the piston using a wire wheel. While you are at it, use the wire wheel to clean up your pad clips and pad guide pins as well.

9) Ensure the cylinders of the caliper are clean. Use the grease supplied in the kit to lightly lube the rubber inner seals. Install the seals into the channels using only your fingers.

10) Use the same grease to lightly lube the outer walls of the piston. Insert the piston into the cylinder about half-way by pressing them in with your fingers.

11) Use the same grease to lube the INSIDE portion of the outer boot. Slide the boot over the piston, ensuring that the seal is square in the piston seal channel and not twisted in any way. Press your finger around the outer radius of the boot to get it to seat flush with the caliper.

12) After the seal is seated, press the piston in the rest of the way using your fingers or the handle of a screwdriver. The outer boot should look uniform at the edge, all the way around. If it isnt, pull on the edge of the boot to get it to seat properly.

13) Use your fingers to spread the C-ring open and place it around the outer edge of the boot. Use a blunt edged tool to help the ring fall into the piston channel.

14) Clean up your newly-rebuilt Subaru 4-pot caliper and re-install it on your car!

This procedure also works for the STi 2-pot rear calipers also. I did all 4 calipers (that is 12 pistons), SS brake lines and a line drain/flush before switching to DOT4 fluid (not to mention the loooooooong bleeding process) and it took me about 6 hours from start to finish. It could have probably been done faster if I wasn't cleaning up all of the pad clips and guide pins with the wire wheel (yeah, Im a prefectionist... so what!) and taking an hour break for lunch. On the other hand, a rounded nut on a brake line or a seized piston could have added a lot of time to the procedure... luckily, that didn't happen.

ConeHead

iTrader: (3)

Instead of using screwdrivers to pry the pistons out, you could also apply compressed air to push them out. Start with a low pressure and slowly increase till piston starts moving. Lesser chance of damaging the pistons this way.

Off topic: I like your location note. Don't know why people are so fascinated by JDM. It doesn't exist in Japan in that sense!!

Imprezer

iTrader: (9)

Yeah, you pop the pistons our with compressed air. Very carefully or you will shoot it out and never find it again.

sigma pi

iTrader: (6)

but the JDM loves teh astro van hehe

Toiletbrush

That's better than what was first suggested to me: Remove the rotor and pads, then stomp the brake pedal to blast the pistons out. I actually used two 45 degree tip prybars to get them out and had a the caliper in a vise with a rag draped under it as a safety net for the piston after it came free.

"JDM" is used on Ebay to double the ending price of any car item being auctioned.

sigma pi

iTrader: (6)

haha so true

im gonna slang astrovans and firebirds on ebay.... JDM hawtness

spectra

how does the 4-pot Subaru brake kit comepare to the other big brake kits out there is it just as good. I am about to do brakes and I don't know if I should pay the extra money for the 4-pot Subaru brake kit or if I shoule just keep my wrx calipers and just put sloted rotors, pads, and SS lines. If I go for the 4-pot kit I would not be able to do my rear brakes for a while. What would be the best thing for me to do, All the brakes or just the front with the 4-pot kit? Need help

Toiletbrush

I think you would actually see more of a difference in braking performance from the pad/rotor/line swap, if that is as far as your wallet will take you in one trip. My car came stock with the 4-pot calipers, so I don't have anything equal to compare against. I can tell you that out of all the things I have done to my braking system, the biggest difference came from a pad swap. After I installed the Project Mu HC+ pads on my fronts, I had to change the way I brake. I found myself under-estimating their bite and would end up locking the front wheels with minmal effort. The best $200 I have spent on my car, indeed.

ADD: If you can do SS lines all-around and still have enough for the 4-pots with pads and rotors in the front, the rears can stay stock for a while. At least until the next payday.