[Mgs] Rebuilding a brake caliper

Eric J Russell ejrussell at mebtel.net
Thu Sep 20 18:07:37 MDT 2007


My understanding is that the condition of the *pistons* is the most
important. Slight pitting of the caliper's bores should not be a
problem as the pistons ride in the seals ID (i.e. the seals do not
ride in the bores the way the rings would do in the cylinders of an
engine). The seal recess should be clean so the seals seat properly.

Pitting of the caliper pistons warrants replacement (of the pistons).

To finish the rebuilds, likely the most problematic part will be
seating the seal retainers. That is a metal ring that is an
interference fit into the caliper's bore. The retainer's function is
to, umm, retain the seal.

There is a 'special tool' available.
http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=59549

My work-around is to partially install the piston, position the new
seal and retainer onto the piston then put an old retainer on top of
that *up-side down*. Then I use a piece of plywood (imitating that
part of the special tool) and a C-clamp to press the
seal/retainer/piston into place. (Don't forget to remove the old
retainer)

Eric Russell
Mebane, NC
http://home.mebtel.net/~ejrussell

----- Original Message ----- 

>  the first step is to ascertain the condition of the bores,
> It is highly probable that the bores will show pitting or
> corrosion -- at this point I would just exchange them for 
> rebuilt units. There is really no point in going any further
>
> Max Heim


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