Need some info on this brake piston deal (pic)?

[2_wacko]

I was changing the rear brake pads and this piece fell off. I noticed the others are loose but stay on with the rubber seal. This one has no rubber seal like the others, should I replace the whole piston or just the rubber seal? Also it never leak brake fluid till I remove the little arm that pushes out. Any info will help me thanks.

 

[BKinzey]

Probably should use a rebuild kit. IIRC they are fairly cheap. I don't know if you can buy just the rubber seal anyway.

 

[sweetk30]

why even reman them. new thay are under 10-15 bucks. i would install 2 new wheel cylinders. as its best to do them in pairs.

 

[MADSTER]

Replace 'em. Sets are cheap and ready to put in with a minimal amount of work.

 

[2_wacko]

Thanks for the info I will be replacing these soon.