I Found the great HP2 Front caliper rebuild thread at A4mods.com http://www.a4mods.com/index.php?page...tml&category=2
which was super helpful and very straightforward.
However, I couldn't seem to find an accurate one for the rears. Many similar but nothing spot on. I just finished the process and I took a couple pictures so I figured I may as well write a DIY for anyone else out there who might be looking to do the same.
Of course as always: I am not liable for anything that may happen as a result of this post, please use this post only as reference material and always see a professional if you're not sure.
Assuming you have removed your carrier (13mm iirc), bleeder screw and brake line and the caliper is off the car. Lets begin.
Tools:
- a few picks
- Wire brushes
- couple small flatheads
- pliers
- hammer :)
- 13mm socket
- T27 Torx bit
- 90* snap ring pliers (ideally)
- Rebuild kit - P/n I used was "CENTRIC 143.33016" @ $7 CAD for 2 plus $15 shipping. -$22.00 CAD Total.
First thing, Take your pliers and pop off the spring on the parking brake mechanism.
Next take the T27 torx bit and remove the fixed metal arm which holds the spring. - Marked B if you look close.
should be left with this
take the parking brake mechanism and fit it in a vise.
You can now rotate the caliper back and forth while leaving the mechanism in the vice. This should spin out the piston. Don't worry about the boot as it needs to be replaced regardless. Once the piston is fully extended, you may rotate it by hand and remove it. Be sure to store it in a clean environment. might even be a good idea to soak it in clean brake fluid.
Just keep turning
brake fluid will come out the bleeder/line holes
Now if we look into the caliper, we are faced with a small snap-ring, (cir-clip, lock-ring, whatever you want to call it). This is the (2nd) biggest P.I.T.A of the whole job. I didn't have the proper 90* snap ring pliers so I used a pick and wedged it around the pad backing and forcing it out. ***Be sure not to lose this as the one in your rebuild kit does not match.*** Also- don't worry, there is nothing spring-loaded behind it so you wont have to watch for anything shooting out at you.
Look on the right side of the picture.
Snap ring removal- wedge pick around pad backing. (or buy proper tools)
taa-daa
Now that the clip is removed you can flip the caliper over and loosen the 13mm nut on the parking brake mechanism. You will have to hammer this piece out, so it might be a good idea to leave the nut threaded on at the end, or use a rubber mallet but be sure not to damage the threads.
Once the arm breaks free, remove the nut, remove the arm, its notched like your wiper arms so you may have to wiggle it to get it free.
Then replace the nut and give it another whack to remove the internals. The inside piece should pop out. Leaving you with this-
Congrats your caliper is now fully disassembled!
Now would be a good time to lay down some fresh paint. Be sure to tape off any openings i.e piston hole. bleeder, line, backing.
Prep accordingly - wire wheel works great. then some primer and a couple coats of high heat paint.
Once the paint is dry its on to rebuilding.
Its a good idea to clean out your calipers of any corrosion or dirt on the inside where the piston goes. smooth clean walls and base are a must before proceeding. Its also a good idea to blast them out with air and brake cleaner. avoid using any cleaning materials that are petroleum based. Personally wouldn't use anything but brake cleaner or brake fluid to clean brake parts. contamination is serious.
Your rebuild kit should look something like this (to the right of the caliper). I also opted to go with some new bleeder valves from Speed bleeder.
Take the smallest o-ring first, and place it on the internal part, push it all the way down. Take note of the recession below the notched area. This is where the V shaped rear washer is going to seat when we slide the internal part in.
Fit the v shaped oring in the rear slot. (sounds dirty but just do it)
Next slide the internal part through the v shaped oring. Keep in mind there is a nipple a the bottom of the caliper and a hole on the bottom of the internal part. it only goes one way, spin it till it locks in the hole. The take the 3rd and final small o-ring and place it in and around the V shaped washer, you can use a pic to push it down all the way. Then go ahead and attach the fixed parking brake bracket with the T27 Torx.
Then line up the rolled part of the moving arm with the bleeder screw hole. leaving a little bit behind it and fasten it on, along with the 13mm nut.
This will hold the internal piece in place while you replace the O-ring. -Remember when I said it was the 2nd biggest pita of the job? well replacing it is the biggest. especially if you don't have the snap ring pliers. I dont have pictures but with the rear mechanism in place it should make things a bit easier.
Finally we get to replace the pistons. You will need some brake fluid and the caliper retraction tool.
Coat the piston seals in some brake fluid for a short while. then pop them in the lower ring.
next I found it easiest to coat the pistons in brake fluid, slide the boots over them and then fit them to the calliper while holding the piston up.
Then start fastening the pistons by hand untill you feel them start to thread on. You will then have to bust out the caliper retraction kit. As you start to retract the piston, it will get very difficult. you will have to stop. pump the ebrake mechanism a few times and then continue, do this as needed until the piston is fully retracted. It is best to leave the lines and bleeder screws out till this is completed.
if you have anything to add just leave a comment and I will include it, hope this helps!
Thanks!
Reply With Quote
Originally Posted by harryn
Bookmarks