Rebuild Calipers - DIY? or Buy Rebuilt?

[Eric_Shea]

Originally Posted by court911man

what is the advantage of having the brakes zinc plated?

Not here to demystify caliper rebuilding. It's a pretty straightforward job. The problems you'll run into revolve around stuck pistons and minimum charges at the plating shops.

The advantage of zinc plating is, zinc is a sacrificial coating. ATE used zinc at the onset (vs. the common misconception of cad). The entire caliper body is plated, even the bore. As a sacrificial coating, the zinc will start to take the corrosion before the metal will. We often see this as white specs on the finish surface as the calipers age. The plating in the bore helps keep the two raw steel surfaces from contacting. Your caliper have lasted 30-40 years now because of the zinc. When we replate some of these calipers, they come out like new because of the zinc that was applied back when they were manufactured. The quality of the steel can be a big issue here as well. 356 calipers are amazing, while the following L-Calipers (early 911 rears) can be problematic. All ATE calipers are yellow zinc BTW.

Years back I did all my own caliper rebuilding (which is how I got started doing this) and, here's what I ran into with a number of the builds; after a few short years, there would be a sticking or pulling issue again. Here what I found out and believe will help you DIY guys:

1. Don't hone the bore. Yup, you read that right. They sell brake hones and, I used those in the past but I believe they are one of the main problems with home-based rebuilds. Honing creates a fresh "steel-on-steel" surface in a hydraulic system that is "open". Water can and will get into your system. This is why we ask you to change your fluid annually. Quick... I'll give you 5 seconds to tell me what happens when water and fresh steel meet each other (no, the answer is not "a 914").

I you feel the need to hone the bore you have bigger issues (whether you care to admit it here or not). You have rust building up around the seal flanges. Paint all you want, say that zinc is "bling" etc. I've pretty much heard it all but, that rust isn't going away. It will come back in a few short years and you'll be doing this again. So don't hone to bare metal and put them back together which leads me to number 2...

2. Google "Metal Plating" in your area. Again, your calipers were probably sticking because of a combination of old fluid build up above the inner bore seal and "rust". You know this to be the case the minute you looked in that bore after you popped the piston out. You cannot hone it away and you cannot pray it away. This will be your problem area in the years to come if you simply wire brush and rattle can your calipers. Find a competent shop to remove all of the rust and re-plate your calipers... Remember, zinc is a sacrificial coating. Your calipers survived this long because of it. Yes, you can purchase el cheapo mass-rebuilder calipers at any auto parts store for less than you can get them from a Porsche specialty retailer. I can get them from my supplier for about $35.00. They then sell them for around $70.00 each. They vibratory polish the finish off the caliper bodies and the fasteners and they give them an oil bath and sell them to you. They turn to rust in a few short months when the oil wears off.

A quick word about paint. It really doesn't do great job of protecting your calipers. It comes off with things like brake cleaner and brake fluid... odd. If you want to pretend you have Big Reds on your car, spray them "after" the zinc plating. Use VHT high temp caliper paint and cure them for 1 hour at 200 deg. It will still mar and smudge the minute you get a drop of brake fluid on it.

We offer the zinc plating service for $30.00 per caliper if you can't find it locally or, if they have a minim charge (which I eluded to earlier and... most do). USPS Flat Rate Boxes make the world smaller and cheaper.

You have to stop this rust or it will return fairly quickly. Your engine makes you go. Your brakes make you stop. You would not rebuild your engine with rusty parts and you wouldn't let $60-120 stand in the way of you rebuilding your engine properly. You don't do that to the engine because, it costs a lot of money to rebuild an engine and, it's not a job you'd like to do twice if it fails. If your engine fails, your car stops. If your brakes fail... your car doesn't stop. Think about it.

You have two caliper bodies to rebuild for your car sitting on a table in front of you. One was zinc plated and the other was wire brushed; which one would you select? OK, now we've pretty much established that it's a price issue and you don't want to pay to have them done right.

3. Stuck Pistons. If you have a stuck piston, you have a rust issue (broken record, I know... but this stuff is rather simple). To remove stuck pistons you need fluid. Fluids do not compress where air does. We use water but a grease gun can work, as mentioned herein, it's a messy task but, it gets the job done. Just make sure you clean all of the fluid passages with brake cleaner before you send the off to the plater.

Happy to help with any questions guys and, sorry... while this is a rather simple DIY job, there a some "Basics" that most people ignore (like removing all of the rust, without honing the bore). Those who know me know I'm passionate about is and, that I'm always eager to help. This is not a shill post. I know a LOT of customers that we've helped through their own restoration process and I'm "way" happy for them because I feel like they got the right product in the end. They saved some coin as well. That said, when you look at seal kits and minimum plating charges and time... I "know" we offer a great service at a great price.

[mreid]

Advice from the expert, free of charge and ignored at your peril.

[rick-l]

What material is the o-ring between the caliper halves?

[Eric_Shea]

Rubber.

[Craig_D]

Hey Eric, thanks for this thorough description. I didn't know that about the sacrificial zinc coating. I learned something here, and I'll be sending you two SC rear calipers with rebuild kits this week.

I have a pair of Carrera calipers that look to have the original zinc coating in good shape that I plan to install the rebuild kit, but if I see any problems during the rebuild, you'll be getting that pair too.

[midnight911]

Originally Posted by esonefour

Job almost done !
You guys inspired me to have a go rebuilding my callipers.
4 hours later and the pistons had new rings and dust covers.
One piston in every calliper was so stubborn, luckily they weren't too deteriorated.
Just need to sort out some decent disks and pads and it will be job complete.

way to go. congrats!

[Iciclehead]

Originally Posted by Eric_Shea

Rubber.

Hi there Eric, I have 4 calipers I am rebuilding, I must confess, I am very much on the side of doing stuff myself more as it is a hobby and the 3 days I might spend rebuilding calipers is actually a significant part of the fun.

I have a good (albeit insane) plater locally (I am in Canada), but my only worry is those wretched O rings between the caliper halves.

Do you source those for us amateur guys or is there a source you can direct us to?

Thanks and your advice is utmostly worthwhile, I was all set to hone the bores after plating, I will follow your advice...

Dennis

[rokemester]

YES go for it, I did but had some "adult supervision" and the great advice on this forum. Doing the brakes on a 911 is the classic "while your at it" kind of job. Started out trying to free up a frozen piston on the front right passenger side caliper. About a month, 4 rotors, pads, new brake lines, split and zinc coated calipers and front wheel bearings sensors and careful bleeding later finally got the the Porsche to stop with the original ATE calipers.

[Bob Harriman]

Eric is the only way to go. They don't get rebuilt. They are restored. The caliper comes back better than new. Pulled my fronts off. Sent them to Eric and got them back a week later. Nice new yellow zinc plated and bolt right on. I sprayed mine with clear gloss VHT caliper paint, baked them in the oven at 200 degrees before putting mine back on. This added process makes the calipers easier to stay clean and new looking for a long time and the brake dust just wipes right off. $236.00 for each pair (two calipers) F or R. While painting is not good, a few coats of clear VHT over new plating doesn't hurt. It's just to keep the plating clean and new looking longer.




By the way, Thanks again Eric

[Eric_Shea]

Looks Great Bob!

Caliper 1/2 Seals are at the bottom of this page...

http://www.pmbperformance.com/calipers.html

[Craig_D]

Eric, beautiful work! I'll be sending these out to you this week (rear SC calipers).

[Eric_Shea]

Your workbench is too neat!

Thanks Craig! We'll keep an eye out for them. Remember, new address (on the web site).

[Craig_D]

Originally Posted by Eric_Shea

Your workbench is too neat!

Thanks Craig! We'll keep an eye out for them. Remember, new address (on the web site).

HAHA I hear that a lot! Ok, I'll make sure to get the info from your site, and will call when I send them.

[Craig_D]

They're officially on their way to you Eric! Triple boxed..

- Craig_D

[Eric_Shea]

(move the blue needle nose pliers one space over to the right)

[Kraftwerk]

Meh.... Learn it, you will love it and then with the saved $$ take yr g/f out to dinner (or you wife... or your Mom)
It's not THAT difficult if you have :
1. Lot's of time
2. Some kind of soap to wash your hands afterwards.
3. compressed air
4. internet: for advice, questions, pictures , testimonials, complaints.

When you hear the "POP" of the seal breaking it is worth the price of admission.

ps. Zinc looks good, real good, I am jealous, I did not split my brakes & have them freshly zinc-ed, maybe next time.
I wish I had done that, besides protecting the caliper, the zinc looks great.

[fanaudical]

Not meaning to hijack, but this is a timely thread for me as I started stripping my calipers and found problems. Some questions:

Front aluminum 'S' calipers (aluminum bodies, steel pistons) - What's the "save" when the pistons are rusted and pitted? Obviously need new pistons, but can those be simply dropped back into the caliper bore if there is minimum wear (i.e. - no rub through the anodize layer)?

[James Brown]

anodizing, cad plating, zinc plating, hard chrome plating, alodine, and painting are all carry-overs from the aircraft industry to prevent corrosion. cool factor is high with plating and it is factory but in the end, a rattle can of what ever paint you have on the shelf will do to slow down the ever present rust. Eric's plating is the best defense on them steel calipers (and look great). Remember "Proper Prep Prevents Poor Pitting Pitfalls in the Plating"

[Eric_Shea]

Originally Posted by fanaudical

Not meaning to hijack, but this is a timely thread for me as I started stripping my calipers and found problems. Some questions:

Front aluminum 'S' calipers (aluminum bodies, steel pistons) - What's the "save" when the pistons are rusted and pitted? Obviously need new pistons, but can those be simply dropped back into the caliper bore if there is minimum wear (i.e. - no rub through the anodize layer)?

No problem... Just about every S-Caliper we restore has bad pistons. To counteract dissimilar metals back in the day, ATE plated the pistons with a nickel plating. As these cars aged and sat, water entered the system, gathered around the rubber and rust would form around the bore seals. Here's what I would do in your situation (if you do not plan to have them re-anodized):

1. Buy 4 DuroAno pistons from our host here. We developed this piston after restoring 930 calipers. Every set of later Brembo calipers with aluminum pistons were perfect internally. To prep the pistons for the rebuild we would simply wipe them off with a soft cloth and wait for the caliper bodies to come back from plating. The answer for the dissimilar metal issues is... No dissimilar metals! The hard anodized coating makes them harder than their heavy steel and stainless steel counter parts. You'll never have this problem again.

2. With a 11mm flare wrench, remove the compensating lines and swap them from one caliper to the other. This will flip the caliper orientation and swap the pattern in the bore. you will notice that there is light scuffing in the bore cavity on the "top" currently. Switching the lines will put that on the bottom. Big deal? Not really but, while you're in there, you might as well. We do this on all our restorations.

3. Swap your knockback mechanisms from your old pistons to your new ones. Watch for the brass barrels under the knockback mechanisms and make sure you don't lose them. Hose them down with brake cleaner and make sure everything is clean. You can also opt to remove them at this time.

4. Put the dust boots on the pistons and butter the inside of the bore and the dust boot flange with assembly lube. If you do not have assembly lube in the dust boot flange it will be nearly impossible to get it to seat properly.

5. Install the bleeders and position the pistons so the notch is at 20 degrees facing the bleeders. Contrary to popular belief, you do not need any special tools or gauges to do this. Drawn an imaginary line down the center of the pad cavity and position the bottom notch on this centerline, again, with the open face pointing toward the bleeders.

The rest should be self explainitory. I would encourage you to have the calipers re-anodized at this time. These are very valuable calipers and will become even moreso as time marches on. You can probably see corrosion in the pad cavity and there is usually some pitting around the fluid inlet flanges as well. Stop it now while you have them apart. If not, use those tips for a clean rebuild.

Hope that helps.

E.

[esonefour]

Would of loved to have had the time to get them sent away to be zinc coated, they look really good!
Track day next week, I hope the factory rotors hold up and my lines turn up :/