DIY - Brake Caliper Rebuild

[smbstyle]

(Disclaimer: I am not responsible for any damage that you may do to yourself or your car during or resulting from this DIY)


So I decided to rebuild the calipers just for preventative maintenance as I track the car often, a few of the dust boots were torn up, and I was going to have the calipers unbolted from the lines anyways as I was changing the brake lines to the Stop-Tech stainless steel lines. It's a lot more simple than most people would think:


Tools you will need:
12mm socket or wrench - banjo bolt (torque to 13 ft/lbs)
14mm socket or wrench - caliper slide pin bolts (torque to 19 ft/lbs)
17mm socket or wrench - caliper bracket (torque to 59 ft/lbs)
Dental pick to remove inner caliper seal
Air compressor (preferred)
Subaru PN# 26297CA000 - Caliper rebuild kit for both sides
Scotch-brite pad
Brake cleaner
Simple green or other all purpose cleaner

Brake Fluid and 10mm wrench for bleeding the lines afterwards (refer to @F1point4s writeup here): http://www.ft86club.com/forums/showthread.php?t=20311



It's a pretty straight forward job; you're simply cleaning the cylinders, pistons and re-installing the different rubber seals.


STEP 1: REMOVE BRAKE LINE FROM CALIPER
Place a drain pan underneath the caliper, and remove the single banjo bolt from the back of the caliper (12mm); to keep the brake lines from dripping a bunch of fluid out, I stuck a vacuum cap inside the opening wrapped in some tape, and had maybe one drop of fluid every 10 seconds.




STEP 2: REMOVE BRAKE CALIPER
Unbolt the caliper from the caliper bracket by removing the two bolts (14mm). The caliper can now be removed completely, but make sure to turn it over the drain pan a few times to drain out the fluid inside.


STEP 3: REMOVE CALIPER BRACKET
Remove the caliper bracket with the two bolts (17mm) and the caliper bracket can now be removed completely.



STEP 4: REMOVE CALIPER PISTONS
Time to bust out the air compressor. You'll need one of the blower tool ends for this step.

Take the caliper, make sure you drained as much brake fluid out as possible, and flip it upside down as pictured below.

Then, place either your stock pads, or a piece of wood or something about the thickness of two pads along the outer edge of the caliper to prevent the pistons from shooting out completely and flying across your garage.

Place the air compressor tool up against the hole on the back of the caliper, and slowly squeeze a little bit of air into the caliper to get the pistons to start moving. *MAKE SURE YOU HAVE THE BACK OF THE CALIPER FACING AWAY TOWARDS A GARAGE WALL OR SOMEWHERE OTHER THAN YOUR EYES/CAR PAINT, ETC., AS SOME REMAINING FLUID MAY SPRAY OUT* As you squeeze, you'll notice that the caliper pistons will usually shoot out abruptly up against the brake pads, wood block, or whatever you use.



Now, take the brake pads out, and slowly wiggle the pistons back and forth, and they will pop right out of the caliper cylinders. Remove the old dust boots from the pistons, and then take your dental pick to pop out the rubber seal on the inside of each caliper bore.

If you don't have an air compressor handy, you can probably just use brake pedal pressure to pop the pistons out, but I haven't tried that way so can't give any feedback on it.






STEP 4: CLEANING
Take your brake cleaner and spray off what you can on the pistons and the brake caliper cylinder bores. Then, lightly run the scotch brite pad over the pistons and the inside of the bores to get any corrosion or build-up off of the surfaces. Spray with brake cleaner again to get any of the particles left from the scotch brite pad cleaning off.

Both the clyinder bore and outside of the piston should be perfectly smooth (you don't need to worry about the inside of the piston, but go for it if you are OCD). After cleaning, give both the cylinder bores and pistons a light spray with the air compressor.

I also decided to clean off some of the surface around the caliper cylinder bores with the scotch brite pad.

Here is a before and after of the pistons from cleaning:








STEP 5: REASSEMBLY
Time to put the caliper back together. Break open your OEM replacement seal kit, which will contain the following:

Caliper cylinder bore seal (4 - 2 for each side, 1 seal per cylinder)
Caliper piston dust boot (4 - 2 for each side, 1 seal per piston)
Caliper slide pin dust boot (4 - 2 for each side, 1 per slide pin)
Caliper slide pin bushing (2 - 1 for each slide pin WITH bushing... only one slide pin on each side has a rubber bushing at the end)
Red caliper bore/piston grease
Pink slide pin grease





First, apply some red grease on the inside of the caliper cylinder bore along where the inner bore seal will sit. Then, apply some light grease onto the rubber surface of the inner cylinder bore seal, and install the cylinder bore seal and make sure it seats properly in the groove. Apply a very light amount of the red grease to the inside of the bore to allow the piston to slide in smoothly.

Next, time to put the dust boot on. This is actually the hardest part of the install, believe it or not. Apply a liberal amount of the red grease onto the outside of the piston, and then put the dust boot onto the BOTTOM of the piston, not the top, as you first need to have the dust boot seat into the groove in the cylinder bore before you seat it around the neck at the top of the piston. For this part, refer to this video at the 6:50 mark: [ame="https://www.youtube.com/watch?v=QXcClOfFmlg"]brake caliper rebuild - YouTube[/ame]


After the dust boot is seated into the cylinder bore, slowly press down the piston into the bore, and once it slides all the way down, the dust boot will actually seat itself around the collar of the piston at the top.


Here's how it should look afterwards:




STEP 6: CALIPER BRACKET CLEANING
Grab the caliper bracket that you took off in step 3, and remove the slide pins ONE AT A TIME so you don't forget which pin goes where (yes, they are different). Clean off the pins themselves with some shop towels and brake cleaner to get the old grease off, and then clean out the bores they slide into by twisting the end of a shop towel and running it into the bore to get the old grease out. Then, spray a little brake cleaner in to get anything out.

For the slide pin with the rubber bushing at the end, simply use the dental pick to remove the old one, grease it up with the PINK grease, and slide the new bushing on.

After you apply a liberal amount of the pink grease on the slide pin, place the new slide pin dust boot on the slide pin itself, and reinstall the slide pin into the caliper bracket




For future cleaning and greasing of the slide pins, you can use this stuff from Napa, it's silicone. If you use a regular grease it WILL gum up and seize up the caliper slide pins.





STEP 7: REINSTALL
(In reverse from step 1 through 3)
Reinstall the caliper bracket (17 mm - 59 ft/lbs), then the brake pads, then the caliper itself (14mm - 19 ft/lbs), and finally re-attach the brake line from the caliper (12mm - 13 ft/lbs).

You must bleed the brakes afterwards, as there is going to be a lot of air in the calipers now. Refer to the link I posted above for bleeding instructions.



Tada, you're done!

[olorin]

You can also use pinch clamps on the brake line to keep the fluid from draining out. I did this when I painted them.

[ATL BRZ]

Excellent write up!

[smbstyle]

Originally Posted by olorin

You can also use pinch clamps on the brake line to keep the fluid from draining out. I did this when I painted them.

personal preference, but I'd rather not pinch the lines and put any un-needed stress on such an important part of the car. I have seen bad, scary brake failures on track from brake lines rupturing due to weak points in the lines, which that exact procedure can induce. just a heads up.

[amram]

Excellent write up! Thanks!!!

[smbstyle]

Oh, and for you track guys, keep in mind that after cleaning and re-lubricating the slide pins, you will experience more severe pad knock-back as the calipers are sliding easily/more freely now.

[JDMenrique]

Nice, thanks!!

[Trap63]

Originally Posted by smbstyle

(Disclaimer: I am not responsible for any damage that you may do to yourself or your car during or resulting from this DIY)



Next, time to put the dust boot on. This is actually the hardest part of the install, believe it or not. Apply a liberal amount of the red grease onto the outside of the piston, and then put the dust boot onto the BOTTOM of the piston, not the top, as you first need to have the dust boot seat into the groove in the cylinder bore before you seat it around the neck at the top of the piston. For this part, refer to this video at the 6:50 mark:

Tada, you're done!

Job is more easy if you "frozen" calipers for 30 minutes @-18/-20C° (-0.40/-4.00ºF)
.

[FyeaFRS]

~RESURRECTION~

Can someone confirm that subi p/n 26697XA000 is the correct kit for the rears

Also, what is the difference between 26297CA000 for the fronts as listed here and 26297FE000..?

[tlim]

I know the original post was a while ago, but I am in the process of doing this and have a question. The directions actually talk about red and ORANGE grease, not red and pink. How did you come to figure out which goes where? Honestly, when looking at the two, the darker one appears more orange to me. Anyway, I track my car so I don't want to get it wrong.

On another note, I didn't have vacuum caps handy, but I did have clear plastic tube and some small C clamps laying around. I squeezed the tube over the end of the hose and then used the clamps to squeeze the tube to make a seal on both sides of the connector. This works well and doesn't drip at all.

[FyeaFRS]

OP's post is all but two years old now, It's possible they've changed the compound or something that it looks different. I'd say if the red looks the same then maybe the other is maybe a different formula or something like that.

[tlim]

Thanks for your reply. I actually zoomed in on one of OP's photos and I can see the instructions are the same, they reference red and orange. My two packages look the same as OP's photos, hence the confusion over "orange". I thought typically you use brake fluid to lubricate the piston seals, am I wrong?

[tlim]

I talked to my mechanic and he agreed the colors were confusing. So to be sure, he gave me a packet he knows is correct for the piston seals. He says it is important to use the correct one for that. If you don't, the rubber seals can swell and cause the pistons to bind.

[kandiflippin]

just knocked this out today, good write up, thanks