I noticed recently after doing a search on rebuilding the rear brake calipers that no one knew how, or they would just suggest that it is too difficult for the ordinary mechanic and we should rebuilt ones. After pricing rebuilt calipers for $70.00 each before core charge, I decided that I should take on this endevor and inform every one else on how easy it was. As long as your e-brake levers are functing properly (as long as they move) this rebuild takes only a half hour to perform.
1. Turn out the pistons in a counterclockwise direction using the piston turning tool or I used a pair of channel locks on the side of the piston. It should only take about 3 revolutions.
2. Remove old snap ring around piston boot, then remove the boot itself and the inner bore seal.
3. Clean every thing in mineral spirits ( mineral spirits wont destroy rubber parts like brake parts cleaner will).
4. Now as long as your ebrake levers can be moved by hand then there is no need to dissassemble the back of the caliper where the e-brake dust boot is.
You can now install the new bore seal with the supllied red grease in the caliper rebuild kit.
5. Next turn the piston into the bore clockwise until it stops moving.
6. Spread the orange grease in between the piston and the recessed grove for the dust boot.
7. Install the dust boot and new snap ring and your done.

Now, If you like being thorough like me you can dissassemble the whole caliper before proceding to step 4. This proccess is more tricky and is probably why no one wants to rebuild them. But, with a shop press or a good c-clamp it is very easy. The only reason you would need to do this is to change the small o-ring on the threaded piston shaft because of fluid leaking out aroud the boot or that there is something broken or seized up inside. I took mine apart for fun, and for r&d purposes. It is also a good time to paint or powder coat your caliper and hardware while it is fully dissassembled. I chose to powder coat them myself.
If you want or need to fully tear the calipers down procede to the next steps before rebuilding.
3a. Remove the large snap ring that attaches the boot to the caliper. Then pull back the boot and reveal the guts.
3b. Clean all the grease so you can see whats going on.
3c. Remove the snap ring on the end of the shaft on the shaft opposite the boot that you pull back.
3d. Pull out the small roll pin next to the retainer spring.
3e. Pry the spring up and away from the caliper right where the roll pin was.
3f. Now using a clamp or shop press, Compress the notched rod under the e-brake shaft lever on its higher side so that is is fully seated.
3g. With the rod compressed the ebrake rod lever will slide out of the caliper. Take care to notice the rod position and the position of all the small parts.
Now you can clean and paint with ease. Simply reat the last steps in reverse to assemble.
I hope this info will help people see how easy it is and how much a rip off rebuilt caliper are. Happy motoring

 

Write ups are great, but most of us are visual and need pics to go with the step by step proceedure. Do that and you will probably have a sticky to call your own.

Good write up.

 

Thanks for taking the time! Good descriptions - though pix would make it PERFECT
regards
Stu Aull
80GS
(contemplating rebuilding rear calipers...)

 

Pic 1 is the kit and all related parts of the caliper.
2. Compressing springs on the piston rod into the small bore on the back of the caliper. Put the high side of the notch towards the roll pin hole. Take care to get it perfectly aligned in order to slide in the ebrake lever rod ( I sighted through the bearings to get it perfect.). Press down on the edge of the high side of the rod to compress the springs to the bottom of the small bore. Also slide in spring at this time with flat slide down and notch toward the roll pin hole.
3. Placing key in slot. Fat side down, and centered as best as possible.
4. Inserted rod. Make sure you you have the right ebrake lever rod, the notch for the cable should face away from the ebrake braket. Also install dust boot at this time or you will have to take it apart and put it back together. If it wont slide throught the bearings you may have to better align the piston rod by repeating step 2.
5. Installed spring, roll pin, and snap ring. First put the snap ring on the end of the shaft to keep it from sliding out. Then install the spring by pressing it down and under the lip of the slot on the ebrake rod with the palm of your hand. Last, tap in the roll pin to retain the spring and the back side is ready to be fully packed with a good brake grease ( I like synthetic), and the dust boot installed by pulling back over and installing the large snap ring.
6. Go by the normal procedure to rebuild the piston side, except you will have to turn the caliper in clockwise to seat. Use a tool available at any parts store for this process. it is a little cube with nubs on it and are very cheap.

Hopefully now every one has the knowledge to rebuild rear brake calipers and not have to pay $70.00 each for rebuilt calipers.

 

My rebuild kit did not come with the grease, I wonder why?

What are the grease types for this job, I 'll have to find some

 

thanks for this writeup. you're a lifesaver ... cherry, even.

this should go in the archives.

 

Mine just came with a set of each of the circled parts wtf?

 

That's what mine had, did the rebuild, just use brake fluid to lube the parts, happy with the results so far

 

aight just checkin was thinking I got screwed

 

Can someone tell me what tools where used? I want to make sure I have everything, all though I am not sure if I am going to rebuild or get remanufactured ones.

 

Will using channel locks on the sides of the piston damage them resulting in poor sealing/leaks? Just curious...

 

They will mar up the surface, bu tas long as you stay on the very outer edge you're ok...that isn't used for any sealing. But the proper way is to borrow the correct tool from AutoZone. This sisn't the AutoZone tool, but it looks just like it:

http://www.brandsplace.com/0246-ap-7860.html

Rich

 

Why use channel locks on the piston? I used compressor to pop them out sound is cool also...lol, keep your fingers clear

For adjustment use this its cheap and works fine

http://cgi.ebay.com/ebaymotors/VW-AU...55131336QQrdZ1

 

I generally use compressed air too, but the rear pistons are threaded into a bolt that is part of the parking brake mechanism...you can't just push them in or out.

Rich

 

ok.. you guys are making me not want to rebuild the freaking calipers. I use to use a puller to push the piston all the way back. I use either a 2 or 3 prong gear puller, to be specific.

Anyway.. what tools will I need to take them apart?? any special tools to put them back together?

 

Thanks for the write-up! I'm going to be doing this in December once I get my powdercoating stuff setup.

 

where did you buy your rebuild kit?

 

The rear calipers are definitely more complicated than the fronts, especially if you decide to take the boot off and clean up/restore the parking brake mechanism. If you leave that alone, the only special tool you'll need is the piston tool I referenced in a previous post. If you do decide to restore the parking brake mechanism there is some info in this thread that might help:

https://www.rx7club.com/1st-generation-specific-1979-1985-18/i-love-restoring-stuff-549854/

Good luck!

Rich

 

BTW, the Autozone rebuild kit includes two large o-rings tht are utterly useless. It doesn't include the o-ring that goes on the parking brake's thru-rod. I took my calipers down, powdercoated, and rebuilt all the guts with the help of this thread. Thanks rotorizit.

Another tidbit... The wedge that goes between the parking brake lever and the shaft went together off-center on both my calipers. It basically over-centers the assembly so that you can't even rotate the "claw" on the end. One well-placed hit from a screwdriver and hammer will seat a well-greased wedge so it all moves freely. I just couldn't get it all assembled and aligned in the first shot. A quick followup blow made it all work great.