Brake Caliper Color

[JimVillers]

I am rebuilding the brake calipers on my 1967 911. What was the original color of the caliper? I have see both black and silver.

[smedley]

Cast iron M calipers, new were yellow phosphate dipped zinc (don't start that cad I or II BS) they turned grey pretty quickly with heat cycling and moisture exposure. If you split one you'll find the original yellow zinc inside.

[Neunelfer]

Mark is correct. ATE used zinc. We've tested multiple NOS calipers.

If you want to duplicate the factory finish you should try 20-25 seconds in the dichromate bath. I like to have a heavy coat of clear in the caliper (for protection) before they go into the dichromate.

Remember, this was a factory process, not much time was spent in the yellow bath. Most platers will want to put a heavy coat of yellow because they are use to it and they think the customer likes in. You'll get a more accurate finish with a light dip.

[JimVillers]

Mark/Eric .... Perfect replays. I have the calipers split and i can see the a very light yellow tinge of the cad plating. While I am trying to be original, I doubt that I will try to plate the calipers. My plater is more industrial than restoration and plating the outside and not the cylinder is not his kind of work. I'll look around for a high temperature paint with hopefully as similar color.

Thanks.

[304065]

Cast iron M calipers, new were yellow phosphate dipped zinc (don't start that cad I or II BS) they turned grey pretty quickly with heat cycling and moisture exposure. If you split one you'll find the original yellow zinc inside.

Chromate. Hexavalent chromate, CRVI. The kind that is banned, worse for our livers than a Key West catamaran ride. Modern chromate is Trivalent, CRIII, looks different, more of a pale yellow.

[304065]

Mark/Eric .... Perfect replays. I have the calipers split and i can see the a very light yellow tinge of the cad plating. While I am trying to be original, I doubt that I will try to plate the calipers. My plater is more industrial than restoration and plating the outside and not the cylinder is not his kind of work. I'll look around for a high temperature paint with hopefully as similar color.

Thanks.

Jim, you should send them to Eric for restoration, he does an amazing job. He also has the right RIBE tools to take them apart.

[Neunelfer]

My plater is more industrial than restoration and plating the outside and not the cylinder is not his kind of work. I'll look around for a high temperature paint with hopefully as similar color.

Huh? Just plate everything. You want the bores replated at this time. Do you think the factory just plated the outside? Paint is a bad move. It comes off with odd things like "BRAKE FLUID" or "BRAKE CLEANER". Factory zinc is a sacrificial coating that will protect them for another 30+ years. You've gotten this far, just do them right. Take everything in for a yellow zinc bath. Have them do a light dip in the yellow if you want them closer to factory.

i can see the a very light yellow tinge of the cad plating

You mean zinc...

It's not rocket science... watch the video:

[Neunelfer]

(Thanks John, check's in the mail)

Seriously, happy to help anyone who wants to try it themselves. I just live for the day when caliper paint goes away!

[Fishcop]

Great video Eric.

I have a zinc plating set up at home... Now I'm inspired

If I wasn't so far away and if postage to and from the US wasn't soooo bloody dear I'd just send mine to you.

[JimVillers]

You guys just got me into more work and research. Painting would have bee so easy (I would have used POR engine paint which is resistant to everything, with stands heat and provides a gloss finish for a long time).

From what I could extract from Google, I think that I need a yellow zinc plater.