Inserting brake pistons back into caliper...

[racingt]

Hi guys, cleaning brakes (SP1 calipers), and popped a piston out.
Tried to reinsert, but the dust seal swelled up, and wouldn't let the piston past.

So, I need a rebuild kit from David Silver, but tips on reinseting pistons would be good so I don't screw it up again.

My maintenance seems to cause a bit of collateral damage.....

[Neosophist]

What did you clean the dust seals with?

Carb / break cleaner will ruin them... rinse them with kerosene and a brush.

Maybe you need to replace the seals.. if you leave them a few days they may dry out and shrink.

Since you have apart anyway maybe best to replace?

Either way... when you have seal that will fit.. use red rubber grease to smear over the seal and fit in the caliper.

Use the same rubber grease to lightly coat the piston.. make sure it is square with the caliper and it will go in easy

[racingt]

Hi Neo
i didn't plan to clean the seals, but one of the four pistons seemed to emerge well before the others, and came out by mistake. seals coverd in brake fluid as it leaked.
Time for a rebuild kit...

[Neosophist]

Hi Neo
i didn't plan to clean the seals, but one of the four pistons seemed to emerge well before the others, and came out by mistake. seals coverd in brake fluid as it leaked.
Time for a rebuild kit...

Brake fluid shouldn't harm the seals... it stands a chance they were old and swollen before the piston came out.. it's only when you remove the piston and they expand can you not get the piston back in.

Yep, rebuild kit is probably goign to best / most cost effective in the long run.

The piston with least resistance will always come out first.. you need to jam it to stop it popping out and allow the others to move you, you can then pull them out with some grips.

It will all come together... leashings of cleaner, make sure everythings spotless, remove all corrosion from the grooves that hold the seals and some red-rubber grease is your friend when rebuilding... can be had from ebay / motorfactors et al