I'm currently trying to refurbish my M16 callipers.

I managed to get the pistons out using the grease gun method, however I've since been advised that grease can wreck calliper seals! Is this the case, and if so, what's the best method to remove the grease from inside the callipers?

I've also found some light corrosion on the surface of the cylinder bores - is this likely to be a problem? I'll get a photo posted up once I haul them out the electrolysis bath!

Jek

wash the grease out with petrol or paraffin. you have removed the seals already?

light corrosion is fine as long as the chroming is not worn away or pitted. polish with very fine wet'n'dry 1000 grade.

if surface is still pitted, then they will seep brake fluid - no need to ask how I now

you can buy new pistons - bigred ? I had to buy one, not more than £ 20 I think.

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Originally posted by JekRankin
once I haul them out the electrolysis bath!

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Providing the pitting is only light you can buy a set of Draper honing stones to use on the electric drill to remove it. Valtra on here is a Draper agent so might be able to help.
Cheers, Pewe

JR V yes need to spilt the caliper to hone but any overhaul kit should include an O ring for the transfer port. Otherwise no problem - just ensure the mating faces are clean before refitting and that the whole caliper body is first de-greased and blown through to remove any grit.

[Edited on 12/6/09 by pewe]

Here's a photo of the corrosion on the cylinder bore. I'd say its fairly light, so I'm thinking I might be able to remove it with some Deox rust dissolving gel.



After the electrolysis, most of the grease had dissolved - I suppose dissolving grease is what soda crystals are most often used for!

PS honing stones sound like a good idea Pewe, but wouldn't that involve splitting the calliper?

Hi jet
I am just in the middle of over hauling my m16 calipers and have ordered stainless pistons and a seal kit from biggred so waiting for the postman to deliver them.
The pistons I took out were just beggining to pit and rust,so i decided to change them. The bores had very slight rust marks so I used t cut to remove and polish up ready for the new pistons, also the discs i had were slightly bent so i bought some new ones today with new pads
regards
Paul

The best stuff for cleaning the grease off would be brake cleaner.I would advise against splitting the caliper halves.