Editing How to Rebuild a Brembo Caliper (section)

===Pre-Warning===

'''Before you start taking things apart, first ensure that your calipers are servicable.'''
First make sure that you can remove the tiny grub screw that you can see in this photo.  It needs a 4.5mm allen key which is a fairly unusual size. An alternative may be to use an imperial 3/16" allen key, although this is often a very tight fit and corrosion inside the allen socket may make it difficult to seat fully. 

[[Image:grubscrew.JPG]]

Unfortunately the grub screw sits deeply recesed in the boss of the caliper by 10-12mm. By the time your calipers reach an age where they would befefit from new seals, the thread in the boss has become so corroded that it's nigh-on impossible to remove the grub screw.  

A no-harm solution is to fill the cavity with penetrating oil and come back tomorrow.  The screw is in tight because the tapered end acts as a fluid seal; there is brake fluid on the opposite side.  Once it breaks loose, it may not be that difficult to remove. 

A brute force solution is to take an angle grinder to the boss and remove the excess material.  Cut the boss flush with the top of the grub screw.  The heat generated by this also helps to free up the screw.

The other part to check is the 13mm bolt that holds the handbrake arm to the caliper.  Make sure that this loosens as it has a tendency to go soft and shear off.  In any case you should not expect the internals of the caliper to support the torque needed to loosen the bolt!  The small parts that are engaged with parking brake actuation are not strong enough to resist the torque of a stuck bolt.  You should put the handbrake arm (only) in a vise and unscrew the bolt so that the resistance torque is only applied to the arm. 

Bear in mind that it's a straightforward job to refurb the sliders but examine your calipers carefully before attempting to replace the piston seals.