Why are brake pistons gold plated?

rat_race

Why are brake pistons gold plated? What is the purpose of that? Serious question.

They're only lightly covered.

D3V!L

For the bling yo !! :cool:

Seriously though, heat dissipation

Max Headroom

D3V!L wrote: »

For the bling yo !! :cool:

Seriously though, heat dissipation

Dont ya mean "dissertation"...

CJhaughey

Not gold probably titanium nitride. Less stiction and corrosion resistance.

Wonda-Boy

Jaysus dont be posting up things like gold in the front calipers, if the low life think there is gold in the front wheels things will get even worse!!!

rat_race

I gently sanded pistons because of corrosion a couple of years ago; I know there are people who will say this is bad, but there was too much corrosion and I would have done more damage removing it all with a sharp object. The gold came off with no effort at all though, after which I regretted it.

Still though, I often sand the pistons...with fine paper. No brake cleaner or tooth brush does the job.

CJhaughey

rat_race wrote: »

I gently sanded pistons because of corrosion a couple of years ago; I know there are people who will say this is bad, but there was too much corrosion and I would have done more damage removing it all with a sharp object. The gold came off with no effort at all though, after which I regretted it.

Still though, I often sand the pistons...with fine paper. No brake cleaner or tooth brush does the job.

Get some red rubber grease and smear that on the piston surfaces inside and out paying attention to the inside of the rubber boot. This will help protect the piston from corroding and is safe for use in hydraulic systems.

rat_race

CJhaughey wrote: »

Get some red rubber grease and smear that on the piston surfaces inside and out paying attention to the inside of the rubber boot. This will help protect the piston from corroding and is safe for use in hydraulic systems.

Thanks, actually ordered some a week ago (need new rubber boots), will use it more often...

Wonda-Boy

Dont be heavy handed with it, very very light smear is all you need.

rat_race

rat_race wrote: »

I gently sanded pistons because of corrosion a couple of years ago; I know there are people who will say this is bad, but there was too much corrosion and I would have done more damage removing it all with a sharp object. The gold came off with no effort at all though, after which I regretted it.

Still though, I often sand the pistons...with fine paper. No brake cleaner or tooth brush does the job.

Never sand them , autosol metal polish will get them looking brand new without damaging the coating unless they are extremely badly corroded, they are fit for the bin anyway in that case.

I've never seen gold on piston calipers, there is some sort of coating on then though

rat_race

Johnathan Gray Schoolmaster wrote: »

Never sand them , autosol metal polish will get them looking brand new without damaging the coating unless they are extremely badly corroded, they are fit for the bin anyway in that case.

I've never seen gold on piston calipers, there is some sort of coating on then though

http://www.v1mx.nl/12017-large_default/brake-caliper-piston-front-nissin-honda-cr80-cr85-crf150r.jpg

That sort of colour, maybe not gold...seen that?

I hear you regarding not sanding, but autosol just didn't cut it for me. But I'll keep it in mind. I did try before.
On Ireland, and with the all-year riding I do, they always seem to get one or two bits of "bad" corrosion on the exposed parts.

rat_race

rat_race wrote: »

http://www.v1mx.nl/12017-large_default/brake-caliper-piston-front-nissin-honda-cr80-cr85-crf150r.jpg

That sort of colour, maybe not gold...seen that?

I hear you regarding not sanding, but autosol just didn't cut it for me. But I'll keep it in mind. I did try before.
On Ireland, and with the all-year riding I do, they always seem to get one or two bits of "bad" corrosion on the exposed parts.

If autosol or metal polish in general doesn't work the piston is properly pitted with corrosion and needs to be thrown in bin. What's your life worth

Wossack

the plating is to reduce stiction, or increase corrosion resistance. Once its gone, one of those functions is kaput, and the piston should be replaced imo.
The problem with sanding them, is you're exposing bare metal, so they'll go bad again very quickly