are these front caliper pistons still usable?

[2007Z6ALL-LED]

There are no scratches at all but there were some spots that I can't explain. I bought the used 2008 front calipers pairs, the caliper and other parts are in pretty good condition.

However the set of pistons doesn't look clean no matter what cleaner I used to clear off those marks ...no scratches at all.

Are these marks meant wears and shouldn't be re-used but new set?

In your opinion/expert experience, are these safe to re-use with the new seals?

 

[kinderwood]

If you run your index fingernail up and down does it "catch" anywhere?

 

[TownsendsFJR1300]

+1 ^^^

Its strictly just rubber from the old seals stuck to the SS. Unless the SS is pitted / scratched they should be ok. Remember, their held in place with rubber, its not like two different metals up against each other interacting with each other..

I had a little bit on a piston or two on mine, the polish cleaned them right up. Use a micro cloth and something like "mothers" polish on them..

I'd put money that if you took your header polish cleaner to them, they'd look /function like new.

Just make sure the aluminum calipers themselves are not pitted...

 

[dpaul007]

I believe mine looked very similar to that when I went through my calipers last year. They were still smooth with no knicks or anything, so I put them back in.

 

[2007Z6ALL-LED]

If you run your index fingernail up and down does it "catch" anywhere?

Nope, not at all - I've been checking for a while on these marks and couldn't find any "catch" at all..


Thx for the input!

 

[FinalImpact]

I would not suggest using any silica related compounds or petroleum based compounds to polish them. It can cause the seals to stick if not COMPLETELY removed. Exhibit A are those black rings. Its in the metals surface and not coming off easily. Think way small like molecules....

Once again, brake rubber swells from contact with petroleum based products. Yes, your looking at a fine layer that should be removed with several applications of brake cleaner. - that said, silicone based polishes have ruined millions of paint jobs while the best surface cleaners were used to remove trace residue. Meaning, even brake cleaner is not enough.

PS i dont smoke but the cellophane wrapper from a pack of smokes (example) when placed on your fingertips acts as an amplifier. Its pretty amazing - instant increased texter awareness.

I do agree its just seal material in the metals pores. Its likely fine as it. Funny you cant clean it off with brake cleaner and soft cloth...

 

[TownsendsFJR1300]

In his first post, he already mentioned he has NEW SEALS so that's a non-issue..

Cleaning EVERYTHING before re-asssembly with brake cleaner is necessary (especially after any piston cleaning)


Basic procedure...:thumbup: