How to: Rebuild Front Calipers, Done! Ready for viewing. Options

[ILoveMySilly97]

For this DIY I'll be rebuilding an 95-97 Avalon Front Caliper but the process is the same/similar to any other calipers.

Disclaimer: This is a backyard DIY. I am not responsible for any mishaps. Follow this how to at your own will. Thank you.

Related links:
How to bleed the brake system.

MY parts list:
Rebuild/Repair Kit - $7.68 from www.rockauto.com

Tools:
Air Compressor
Degreaser - I used simple green mixed with some dish soap and some water in a spray bottle
Brush or something to scrub with
Wire brush - only needed for rusted parts
DOT3/4 Brake Fluid - I used DOT 4
Brake Cleaner
C-clamp

Step one:
Forcing the piston(s) out.


Since I'm using the Avalon calipers. It has two pistons. So it's a bit tricky. If you're rebuilding the stock GT or ST single piston caliper. It's much easier. All you have to do is get an air compressor and stick the nozzle into the hole where the 14mm nut(circled in the picture) and spray air into it. But make sure that you have an old brake pad or something to catch it because it'll come out with FORCE.


For the two piston calipers. One piston will come out and the other one will still be stuck in there. Once one of them comes out. Just stick the one that came out back into the cylinder but not all the way. Just enough to sit on the seal inside. Then have a block or something hold it in place(I forgot to take pics while doing this step but I drew in a "block" and just imagine the other one with the boot on was still all the way inside the cylinder.) to prevent it from coming out. This will force the other one to come out instead.


Once the other one comes out then you just need pliers to pull out the other one. Make sure you bite just the lip of it. Not the body of the cylinder.

Step two:
Removing the "guts" ie. seals, boot, C-clip(if it has one)

(Sorry I didn't get a picture of this but it's self explanatory)
This process is easy. To remove the boot. All you do is pull on it. Don't be afraid to rip it. You're rebuilding it for a reason.

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Now the seal you'll have to stick a small flat head into it. Lift it out of it's groove and push it out of place. Then just pull it out with your hand.


Mine had a C-clip. To remove it. You'll have to stick a small flat head to lift it out of the groove.


Then have another flat head to help brace it. While you pull it back. I used a small nail's head to help pull it out towards me.


Once it's out of place you just pull it out with your hands.


Here's everything taken apart.

Step 3:
Cleaning it up.

Sorry for no picture since I didn't need to do this process.
This process is easy. Wire brush anything that is rusted. I didn't need to since there wasn't anything too rusted.


Then clean it some degreaser and rinse with water. Just brush away. I used an old tooth brush and a dish sponge. Clean both the pistons and the cylinders. Make sure you get into the groove good. It's kind of hard to reach but a brush would work.

Step 4:
Inspection. This is the most important step of this process. This will determine if the caliper is even worth rebuilding or not.


Inspect the cylinder walls and pistons for any heavy scratches or grooves(besides the seal and boot groove). If it's scratched then just ditch this rebuild and buy a new caliper.


Here's an example of a pitted bad piston. A bad cylinder wall will look similar to this also.

Step 5:
Lubing the parts.


Lube the cylinder wall, pistons, and seal with brake fluid ONLY! Not with motor oil, potroleum, or whatever. Just BRAKE FLUID!

Step 6:
Seating the Seal.


Sit it into the groove and make sure it's all the way in there. Basically reverse process.

Step 7:
Seating the boot.


Easiest and best way is to "dress" the bottom of the cylinder with the boot. Make sure that the lip of the boot is on the bottom so it can be set to align into the it's groove in the cylinder wall.


Then just sit on top of the cylinder. Do not try to push the piston in. All you need to do is wiggle the piston side to side to make it easier to tuck in the boot. Start tucking all around in with a small flat head. Make sure it's seated all around before going to the next step.

Step 8:
Seating the C-Clip.


There's a gap for the C-clip to go into. Here's a pic of me tilting the piston to lift up the cap for the c-lip. The left on is when it's not tilted and the right on is the one that's tilted. The goal is to put the clip into that gap all around.


Stick one end into the gap and then work your way around tucking it in with a small flat head. The easiest way to work with any c-clip is to try your best to "close" the clip to make it easier to go into place before opening. Again. Be sure the C-Clip is seated before proceeding to next step.

Step 9:
Putting the Piston back into the caliper.

(Didn't get a picture. Sorry.)
Set the piston into the walls with your hand. Push it in as much as you can.


Put a brake bad between the piston and the C-Clamp. Start screwing the C-Clamp until the piston starts going in.


Just a FYI, it shouldn't take much force to drive the piston into the caliper. If you feel you're starting to use too much force. Just pull the piston back out with the plier. and try again. The reason it gets stuck is because it's biting the seal and you don't want to damage a new seal so be patient.

Step 10:
Now do the same for the other cylinders and you're done!



TADA!

This post has been edited by ILoveMySilly97: Aug 6, 2015 - 7:52 PM

[Jmk91]

Do Avalon capilers use same pads as gt calipers?

This post has been edited by Jmk91: Jul 30, 2015 - 4:34 PM

[ILoveMySilly97]

Do Avalon capilers use same pads as gt calipers?

From what I've read. It's all BOLT on for the conversion but I don't know anything for sure until I physically see it in person. Follow my other how to thread for the avalon caliper conversion to stay updated as I do it.

[jesse09]

For the piston calipers. Did you buy new ones? or just clean them up really good lol I can't tell

[ILoveMySilly97]

For the piston calipers. Did you buy new ones? or just clean them up really good lol I can't tell

I just cleaned them up real good. If they're still smooth then the caliper is still good. If they're pitted then its cheaper to replace the whole caliper. Pistons costs too much. Lol

[jordisonjr]

Solid Write up. I vote for Sticky!

[ILoveMySilly97]

Do Avalon capilers use same pads as gt calipers?

From what I've read. It's all BOLT on for the conversion but I don't know anything for sure until I physically see it in person. Follow my other how to thread for the avalon caliper conversion to stay updated as I do it.

They're bolt on. I made another thread.

Solid Write up. I vote for Sticky!

Thanks. Lol

[njccmd2002]

i followed your instructions. i got dorman d352006. 43 mm bore kit. but that piece of crap kit, not oem, has a inner seal thats more then 45mm, and it wont fot. did you have any trouble with the kits. what part u used

[ILoveMySilly97]

i followed your instructions. i got dorman d352006. 43 mm bore kit. but that piece of crap kit, not oem, has a inner seal thats more then 45mm, and it wont fot. did you have any trouble with the kits. what part u used

Tbh. I don't remember which kit I used. All I remember was I bought it off of rock auto while it was on closeout sale.

[njccmd2002]

i should have bought oem. Anyways the inner seals were good on the caliper, and recycled them. used the new boots.