http://www.thisoldtractor.com/gtbender/
Updated: 2011 Aug 20
Thanks to Neville Goldsmith for sending me this information via email. In Neville's own words:
I am trying to source a Piston and Seal Rebuild Kit for [the rear brake caliper on my 2003 Moto Guzzi California EV touring], but was told by my normal supplier here in the UK, that no kit was available. It is a Brembo PF 30/32, Part No 22.5555.32. From the manual information on your site the Moto Guzzi part No is MG# 03653001. What I am trying to do is to see if this caliper is used by other manufactures on their bikes to see if I can get a kit from them if Guzzi won't supply it.
Gregory Bender's reply to Neville:
I've done a bit of searching, and I've found that Brembo part number 22.5555.32 was also used on the following machine: Aprilia Pegaso (1997 - 2000) front left caliper
Unfortunately, I can't seem to find any other applications.
Hopefully this helps.
More information from Neville:
I contacted my local Aprilia dealer and they informed me that Aprilia don't list a seal kit for the Pegaso either. However, they did manage to find out that this caliper is also fitted to a Honda model (or so they said!) and have been able to supply me with the seals OK. Brembo kits that I have bought in the past have been Seal & Piston Kits, but they only supplied the seals. Fortunately my pistons were fine to re-use. The seals were in Brembo containers and fitted perfectly.
While I had the pistons out I measured their respective diameters at 31 mm and 32 mm, so I find it strange that the caliper is called a PF 30/32. The smaller one is definitely 31 mm. Weird eh!!
Once again, thanks for your help, at least I got what I needed in the end.