Question about brake caliper painting - what parts not to paint

[eljay]

I have a set of used stock B7 calipers off the car. I will be cleaning them up and then I plan to paint them black with a Duplicolor brush-on kit.

Should I only paint the outer half of the caliper or also the aluminum half that houses the piston? If only half, do I need to disassemble it into the halves?
Also, is it OK to paint the inside of the caliper where the pads sit or should that be avoided because the pads need to slide on those surfaces?

Thanks!

[Axis]

Never take it apart. You can paint everything but the piston/dust boot/bleed nipples.

[eljay]

Well, I want to replace piston seals and dust boots as part of the rebuild anyway, so I'm just wondering if I should take the two halves apart and paint just one. It will be tough to paint around the screws without taking them out.

[Axis]

Well, I want to replace piston seals and dust boots as part of the rebuild anyway, so I'm just wondering if I should take the two halves apart and paint just one. It will be tough to paint around the screws without taking them out.

You dont need, nor should you take them apart for a rebuild.

[rongeur]

I took mine apart for powder coating, shouldn't be a huge deal. I would use new bolt and make sure to torque them down correctly, consider blue or red loctite.
I did a full rebuild for some s4 calipers, fronts and rears and they were pretty grungy.

[vwnobby]

Not disagreeing with Axis, but I media blasted mine, then cleaned them up, took them apart, had them powder coated and put back together. complete rebuild. No issues since.
If I were to do it again though, I would keep them together and just paint them.

http://www.audizine.com/forum/showth...=1#post7845742

[Axis]

I was only saying that because ate states that these should not be taken apart. I know it can be done, I've done it myself in the past.

Edit : Here I linked your images :P





I had a set powder coated without taking them apart (Potato quality)

[vwnobby]

Edit : Here I linked your images :P

Thanks

I couldn't find the proper torque specs for the bolts afterwards so it's tough to judge how much to tighten them.
Again, if I were to do it again, I'd keep them together. Only added benefit (not a huge one) was that I was able to paint the bolts silver. You know, the bolts that are on the back side that no one will ever see once the caliper is mounted. :P

[Axis]

Thanks

I couldn't find the proper torque specs for the bolts afterwards so it's tough to judge how much to tighten them.
Again, if I were to do it again, I'd keep them together. Only added benefit (not a huge one) was that I was able to paint the bolts silver. You know, the bolts that are on the back side that no one will ever see once the caliper is mounted. :P

There's no torque specs available from ATE hence why you didnt find them ;) I powder coated those bolts lol F.it.

I just emptied them, removed piston, dust boot and piston seal. Sandblasted to a smooth finish (you can almost see the mirror finish on my picture taken with a potato) and powder coated piano black.

Diagnastociator had a great post somewhere with the reasosn why these should'nt be slit in halves but I cant find it

[eljay]

Thanks guys! I'm not looking to invent extra work if it's not needed. I just saw some folks painting only the outer half and then I saw this DIY with the half removed.
I will paint the whole thing as I want to keep it from getting nasty again.
Any issues with painting the insides where the pads slide? How are your surfaces holding up there?

[vvenom800tt]

Dont use a brush on kit, its a pain in the ass, ask me how i know.

Just spray them

[eljay]

I know spray would be better, but from my experience, unless you build a spray booth, it goes EVERYWHERE even if you don't see it. And I don't want to be covering everything in the garage nor do I want to spray outside and have the wind take it to my siding and windows.

[vwnobby]

Any issues with painting the insides where the pads slide? How are your surfaces holding up there?

Mine are holding up, but I think since I went with a matte finish powder coat all the brake dust has built up on the textured surface so it doesn't look as nice as it used to. I have my old set that I'm thinking about painting. Still have a G2 caliper paint kit sitting in my garage and I may try that.

[eljay]

Did you clearcoat the matte black?

Also, since I have all the caliper rebuild gurus here, which brand of seals did you use? Centric kits are $5 at Rock Auto, while Ate kits are $25.

[vwnobby]

Did you clearcoat the matte black?

Also, since I have all the caliper rebuild gurus here, which brand of seals did you use? Centric kits are $5 at Rock Auto, while Ate kits are $25.

Nah, I didn't clear coat. Didn't think of it since it was powder coated.
I used OEM seals since I had a friend who worked at the dealer. I also decided to go with the Tyrol stiffening kit while I had everything apart.

[Denio24]

@Axis Any idea why these calipers shouldn't be rebuilt.....not just b/c ATE says so? And... do you have references to where you found that out?

[Axis]

@Axis Any idea why these calipers shouldn't be rebuilt.....not just b/c ATE says so? And... do you have references to where you found that out?

I never mentionned they should'nt be rebuilt. I rebuilt two sets with news seal and dust boot.

I said they should'nt be slit in half.

[eljay]

Nah, I didn't clear coat. Didn't think of it since it was powder coated.
I used OEM seals since I had a friend who worked at the dealer. I also decided to go with the Tyrol stiffening kit while I had everything apart.

I would love to get the Tyrolsport kit too. I cannot find it anywhere in Canada. :( And with the current exchange rate and who knows how much for shipping, it will be close to CAD$160. I'm sure they are worth it, but I find that a bit too much for a set of bushings and pins. I'll have to decide... I'll probably bite the bullet in the end.

[rongeur]

Did you clearcoat the matte black?

Also, since I have all the caliper rebuild gurus here, which brand of seals did you use? Centric kits are $5 at Rock Auto, while Ate kits are $25.

I used Centric. If they fail, I will go Ate but centric makes most blanks for other name brand companies (rotor wise) so I assume the similar goes for other parts. I have no official evidence to back that up but I have had three sets of centric rotors and they have all been better excellent.

[Mister W]

Have to paint mine soon. I was about to spray them on the car but it would do a better job to remove them. But i dont know how to disconnect the caliper from the line and how do you do to not lose the oil. Do you have to bleed them after?
thx

[Denio24]

Get a flare wrench and when removing the fitting apply pb blaster. Sometimes the line gets fused to the nut so slowly work the nut back and forth. Just apply a cap to the line so the master cylinder doesnt go empty. The brakes will have to be bled.

Sent from my SM-G920P using Tapatalk

[Axis]

@Denio24 : I found the link where John mentions they should'nt be split in halves : Clicky Click

The B6 S4 and B7 A4 front calipers should not be fully disassembled. Do not seprate the alumimum section from the iron part of the caliper.
There is no reason to break the caliperes down that far. Use a 6" 2 X 4 to block the piston when removing with compressed air.

The calipers are assemblies of aluminum and iron. The two parts are bolted together, do not unbolt and seperate the two main caliper components. To rebuild and powder coat, disassemble the piston from the caliper cylinder, revome the piston seals, and mounting hardware. Avoid glass beading the caliper parts.




Do not remove the bolts on the side, and seperate the aluminum part fro the iron black colored part.

The manufacturer, Ate, advises that seperating the two main caliper parts is not allowed. I don't know the details about why this is the case. I am sure there are technical reasons for this.

From Audi: "With the exception of "replacing brake pads" Brake Pads, FNR- G 60 (Front Brakes) , and "Servicing front brake caliper" , no repairs may be performed on the brake caliper."

None of the service procedures show the caliper disassembled, and there is no torque specification provided for the four large torx bolt holding the caliper together.

There are a few special tools shown for reassembling the piston into the caliper cylinder, with specific details about correctly installing the new seal and dust boot.

Since Audi does not provide any re tightening specs for the four torx bolts holding the caliper aluminum and iron parts together, and states that no repairs to the caliper itself are allowed, those two facts are consistent with the manufacturers information from Ate (Ahh-Tay, originally Allen Tevis, ) saying the caliper is not supposed to be disassembled.

[Charles.waite]

It's drives me nuts that that stupid DIY hasn't been edited or removed. So so dumb...

[rongeur]

I agree with Axis and not trying to keep the argument / discussion going, but there are plenty of things that we disassemble on our cars that we do anyway...

Diverter valve disassembly to install GFB internals..

Any HPFP unit to install aftermarket internals...

Definitely not advertising that everyone should split their calipers apart, but we shouldn't be fearful to do so if we have a reason to do so. Being mechanically inclined and using good common sense is always a must, especially with brakes.

Google searching for ATE brake rebuilds (other platforms) will advise between 20-30N/m torque for the bolts. Protect yourself with some loctite and double check the torques after bedding in new pads should be more than sufficient to ensure a good seating of the halves. Anything you do to your car outside of manufacturer design is taking a risk in some form or another.

[Charles.waite]

I agree with Axis and not trying to keep the argument / discussion going, but there are plenty of things that we disassemble on our cars that we do anyway...

Diverter valve disassembly to install GFB internals..

Any HPFP unit to install aftermarket internals...

Definitely not advertising that everyone should split their calipers apart, but we shouldn't be fearful to do so if we have a reason to do so. Being mechanically inclined and using good common sense is always a must, especially with brakes.

Google searching for ATE brake rebuilds (other platforms) will advise between 20-30N/m torque for the bolts. Protect yourself with some loctite and double check the torques after bedding in new pads should be more than sufficient to ensure a good seating of the halves. Anything you do to your car outside of manufacturer design is taking a risk in some form or another.

Oh absolutely. But recommending the random person googling a brake pad replacement DIY to separate the caliper halves is idiotic.

[Axis]

I agree with Axis and not trying to keep the argument / discussion going, but there are plenty of things that we disassemble on our cars that we do anyway...

Diverter valve disassembly to install GFB internals..

Any HPFP unit to install aftermarket internals...

Definitely not advertising that everyone should split their calipers apart, but we shouldn't be fearful to do so if we have a reason to do so. Being mechanically inclined and using good common sense is always a must, especially with brakes.

Google searching for ATE brake rebuilds (other platforms) will advise between 20-30N/m torque for the bolts. Protect yourself with some loctite and double check the torques after bedding in new pads should be more than sufficient to ensure a good seating of the halves. Anything you do to your car outside of manufacturer design is taking a risk in some form or another.

I agree, I was just mentionning it wasnt necessary to split them to paint them or even to powder coat them. As mentionend earlier I split some ATE caliper down myself, looked everywhere for torque specs and ended on the thread I linked above. I did like you did, used red loctite and might of torque them to a bit more then 30N/m lol

Btw, I have upgraded hpfp internals and a DV+ :)

And that DIY should definitely by closed/taken down. I think I'll take pictures next time I remove my B7 brakes (For ever) and submit a DIY to Kristokes.

[eljay]

Another silly question... I started removing rust from the calipers with a cup wire brush that's steel, but brass plated. The surface quickly becomes smooth, but what was before a rust spot is now a dark black spot after going over it with the wire brush on a drill. Do I need to keep at it until the spots disappear and there's nothing but shiny clean metal or is what I have sufficient and can I paint it?
I'll post a pic later if it would help.

[vvenom800tt]

I dont think its gonna become shiny metal as its a cast part. Just sand it down until its bare metal and somewhat smooth. Then just brake clean that bitch and start priming

[vwblackb5]

Photo of what not to do

[Charles.waite]

Wait..... That's real? As in someone actually did that? Jesus....

[eljay]

Photo of what not to do

Hey, where did you find the photo of my brake paint job??!! .
LOL

I've seen that picture before and it still makes me laugh.

[eljay]

Here is what I meant by those dark spots.


It seems that once I went over the surface with the brass-coated wire brush it becomes kind of "oily" and shiny and makes it harder to remove those dark spots, which are essentially the rust spots, but sort of "sealed over" by the brush action. I hope that makes sense.
Do I need to keep grinding until they are gone before painting? If I paint over this (after cleaning the surface, of course), do I risk paint flaking off in those spots or will the paint seal it further and be fine?
Thanks!

[vvenom800tt]

If i were you, with that much rust i would take them to a powdercoat place and have them media/sand blasted. Then just pay them to powdercoat them. Its so much easier and it holds up 100 times better than rattlecan.

I regret not powdercoating my rears

[Charles.waite]

Or just brush on Evaporust. Then prime and paint.

[eljay]

If i were you, with that much rust i would take them to a powdercoat place and have them media/sand blasted. Then just pay them to powdercoat them. Its so much easier and it holds up 100 times better than rattlecan.

I regret not powdercoating my rears

You guys are not giving me much hope! lol
This is my daily driver, so I was hoping not to spend a ton of cash on new brakes, but it seems to be heading in that direction. I just cannot find someone in the area who would do it and I don't have anyone I know in the this magic trade. :(
I'll keep trying though, because this is turning out to be a giant PITA.
As bad as they were rusted, the pistons came out easily and there's not a speck of rust on them or the bore and the e-brake mechanism operates freely, although I will be replacing all of those seals.

[eljay]

Or just brush on Evaporust. Then prime and paint.

Did you mean POR-15 or similar rust paint? To use Evapo-rust, you must soak/submerge the part in it or otherwise keep the parts wet with the stuff to allow it to work. In fact, the caliper you see in the picture has been submerged in Evapo-Rust for one week! It works, but it's expensive and I think I'd need another 2 gallons of the stuff to get these cleaned, so I gave up on it for this project.

So, are those black spots still an issue then?

[Charles.waite]

Ideally you submerge it. But the instructions say you can brush it on as well. It will still do a decent job of converting the rust. That what I did on my calipers. They're weren't as rust as yours but were fairly similar. The Evaporust worked well.

[martin0079]

Well their are other options. Like just ordering reman calipers and sending in that rusted one for the core. That is sort of what I did. None of my calipers are bad though just changing out to S4 brakes. It was the cheapest way I found to get the carriers and I don't have to take them off the car and wait for paint. I haven't done the swap yet just getting all the parts in right now. Once I have them in I am bringing the calipers to a local epoxy painter.

[Denio24]

On my old b6 i just built a blast cabinet, blasted with glass/ walnut media, disassembled, and washed the caliper out with mineral spirits. After that took another wipedown with wax+grease remover. Then I masked, painted, and assembled. Much better result than just painting on the rotor, and cheaper than powder coating.

[eljay]

Well their are other options. Like just ordering reman calipers and sending in that rusted one for the core. That is sort of what I did. None of my calipers are bad though just changing out to S4 brakes. It was the cheapest way I found to get the carriers and I don't have to take them off the car and wait for paint. I haven't done the swap yet just getting all the parts in right now. Once I have them in I am bringing the calipers to a local epoxy painter.

Well, I priced it out and it would cost me a lot more than I'd like to spend. I'm in Canada, so shipping cores back kills the reman deal. Also, FYI, I bought this used set to put onto my B6, so I'd have to add the price I've already paid for them into the equation.

I managed to get one quote for sandblasting and powdercoating and it's $200. Hoping to get it a bit cheaper, but that's not bad and I think I will just go with that.

I just bought the rotors too (Ate PremiumOne) and I will be getting the Posi-Quiet Ceramic pads, I think.
Of course, after I bought the rotors a set of front B6S4 calipers and carriers shows up for sale!! This is a daily driver, but S4 front brakes are tempting. But I'd have to return these rotors and get something more expensive for the front. I know that I can just get the carriers from the B6S4 brakes and run the larger 345mm rotor with my B7A4 caliper. I think I will just stick with my B7 brakes. Ah, decisions.