I am a bit bored so I thought it a good idea to share all I know about the little brembo calipers some of us like to use at the rear...
There are two types of twin* opposed* piston Brembo calipers in the modern* mainstream:
The early one:
One interesting thing is that there is a version available with the feed on the opposite side, but I have never seen this as original fitment to a bike:
And the later one:
Each has its advantages and disadvantages...
Early:
Advantage - Top feed which means that you don't need additional space for the line fitting
Advantage - Pads are cheap
Disadvantage - Seals are not available (but I'll let you into a secret later)
Disadvantage - The feed is fixed to one end
Late:
Advantage - Changeable side feed which means that you can move the line fitting from one end to the other - swap the banjo bolt with the bleed nipple
Advantage - Readily available (I'll let you into that secret later)
Advantage - Bigger pad area
Advantage - Available in 32 or 34mm piston diameters
Advantage - Seals for the 34mm variant are available
Disadvantage - Seals for the 32mm variant are not available (but I'll let you into a secret later)
Disadvantage - The side feed needs some space for the line fitting
So, for hidden calipers on tuber, XB or 1125, the early caliper is the best choice (tuber drawings shown):
For exposed calipers, the later caliper is best choice cos you can move the line fitting and there is no restriction on the side feed:
So, where can you get them? New, from Bike Torque Racing. Secondhand, from EBay...
But where are the best deals to be had? What do you search for? And here comes the secret cos if I hadn't ended up devoting my life to being a PITA I would have probably been a detective, and I do like to keep my detective skills sharp by reading Jo Nesbo, Peter Robinson and Henning Mankell books.
So, lets look at the older caliper... Lets start by picking a bike it is on, how about a 1992 Ducati Monster?
Next, lets look in the EBC catalogue for what pads are fitted to the rear of a 1993 Ducati Monster:
And we find it is an FA047 (I like to use the HH pads).
But where else can I find this caliper? Good question, and this is where detective skills come in. We look in the rear of the very useful EBC catalogue for what else that pad fits, and you will see there are loads. For instance, my black S1 uses a caliper off a certain year of TZR125 (which is finished in silver - the caliper, not necessarily the bike).
As for the later caliper, this is fitted to Adam's Ducati, so a search for the pads for a Ducati 1098 will give you a part number that you can cross check with... And if you do the cross check, you will be very very surprised what you can search for on ebay (bet nobody can be arsed to do the legwork here
).So, if you do get a secondhand caliper, you are not going to want to put it straight on without cleaning it and putting fresh pads in. Of course, you could just pull the pads and clean it with WD40 and a toothbrush, this would be fine if you know the caliper, but it is certainly not enough for me with an ebay caliper.
The calipers split down the middle, being held together by M8 allen screws. So, you need to remove them, split the caliper but make sure you don't lose the two little O-rings.
Then pull the pistons out... There are lots of tools to do this with, my favourite is this Laser tool:
It even has an attachable slide hammer, but I have never needed this. The expanding plug doesn't damage the pistons and once tight grips firmly on the inside of piston enabling you to twist and extract it. Its a good idea to use a bit of brake cleaner inside the piston to let the plug grip it easily.
Then, carefully pull the seals cos you are going to need these. Inspect them, make sure they are not torn, worn or chemically corroded (by a bellend using a non rubber specific grease on them)...
Then chuck the calipers in the ultrasonic cleaner:
Using this at max strangth from Maplin:
An hour in there at max temp gives you a clean caliper:
Check the seal grooves, if there is any sign of corrosion, you will need to get the Dremel out and clean them up with one of these:
Seals can then be cleaned with a rag only! Go on, you can use a bit of brake fluid if you really must. Take great care not to damage them or get them exposed to anything other than brake fluid or rubber specific grease (like Castrol red grease). Note that the outer seal has groove in it to catch crap, use a scribe or electrician's screwdriver to carefully pick the muck out.
Check the pistons for scoring then clean them with your favourite brand of brake cleaner and get all the circumferential lines of crap off.
The seals can be greased with Castrol red rubber grease and replaced.
Then push the pistons in carefully all the way.
Clean the o-rings and apply a bit of Castrol red grease to them and then put them in position.
Put the sides together and bolt together using the allen bolts. These are zinc plated bolts from the factory, and being in a position where everyone forgets, they do go rusty, so you could always replace them with new bolts.
Then, all that is left is to put the bleed nipple and banjo bolt in place.
Other considerations:
Engineering drawings. Are there any? Sure:
Attachment:
Attachment:
Copper washers. I am all for recycling and used copper washer do not always seal as well as they used to. Our friend Fozberry wrote a nice article for us here - viewtopic.php?f=17&t=6133
Seals. Here is a great secret which I am going to let you in on. If you went to your Ducati dealer and said, 'can I have some seals for my rear caliper?' they would say 'Sorry, you have to buy the whole caliper' resulting in you thinking 'damn'. But they are available, Brembo wont sell you them as from the engineering drawings, they are not listed as a spare...
But if you have an early 32mm piston caliper, you will need:
1 x Ducati part 800029627 for the inner seals (about £20)
2 x KTM part 50313081000 (about £5) or 1 x KTM part 69013081000 (about £15) for the outer seals (about £5)
For a late 32mm piston caliper, you will need:
1 x KTM part 69013081000 (about £15) for the inner and outer seals
For a late 34mm piston caliper, you will need:
2 x KTM part 54613318200 (about £5) - TBD
I'll post some more pics in due course...
* this is a caveat
one tip when fitting pistons in reseald caliphers....... rotate the piston at the same time as feeding it through the new seals 
