apheod

I took my brand new CTS-v calipers to the most highly recommended local powdercoater, who seemed very confident they could handle this job. I was very explicit when I dropped them off, all bleeder holes and brake line ports were to be plugged (which they did) and none of the black anodized areas were to be touched, by sandblast or powdercoat.

They plugged the bleeder and line ports, and most of the piston bores, and blasted all of the black anodized mounting surfaces, including the outside edges of all piston bores, and the very top of a few of them. One of the calipers has 2 bores like this, the rest have 1 each.

Obviously, I was not very happy, but the damage was done. I took them without powdercoat, hoping I could ship them off to someone who knew what they were doing, as I should have done in the first place.

Now, I'm getting conflicting opinions. Google-fu has only turned up a few forum posts where a guy had all of his piston bores blasted, without being plugged at all, and the general consensus is that they're trash. I already know Brembo will tell me these are not useable to cover their asses. I've spoken with a rebuilder in Canada who says he can fix this by honing the cylinders, but I've seen people say on forums that honing is a major no-no, and others saying it's just fine. I e-mailed Mike the powdercoater, the most highly recommended coater online, and he said there would be no contact between the piston and bore, and that it would be fine as is, but that I could hone the bores if I wanted peace of mind.

Here is the link for the Canadian rebuilder I found. I'm leaning towards this being my best option, but obviously shipping to Canada and back is not ideal.

http://www.brightsidecoatings.com/blog/?page_id=155

This is what they looked like prior to being blasted.



These are pictures of the worst one.





The rest have one cylinder each that look like this.

JJsQwuik

iTrader: (17)

I wouldn't think so because there's a little recess grove where the o-ring/seal for the piston sits wasn't affected. The o-ring is what prevents the fluid from passing thru and leaking out. The outer seal/dust cover is just to prevent any dirt debris from getting between the actual caliper and piston.

apheod

So there will be no contact between the sidewall of the cylinder and the piston? My concern was the roughness of the blasted area causing premature wear on the pistons and/or dustboots. I would just stick one in to see, but I'm afraid of scratching up the piston in the process if the surface is too rough.

Also, does anyone know where I can purchase a hone for these calipers? Google wasn't turning up anything specific for the task, do I need to measure and buy a proper sized hone?

01ssreda4

iTrader: (96)

Id run them, that spot is dry, like stated above.

gm02ceta

iTrader: (9)

Just from the pics it appears the cylinder bore itself didn't get blasted. ALL the bores should have been properly sealed before blasting. The issue is did any of the media get into any of the open bores? Any residue of media inside the caliper will score the walls and cause more overall damage to the entire braking system!