PIAGGIO X9 Service Station Manual page 191

Braking system
Brake caliper overhaul
Disassembly
Proceed as follows:
1 ) remove the to socket-head screws (1 ) and withdraw
the two brake pads (10);
2) remove the two socket-head screws (2) and remove
the opposing plate (3);
3) withdraw the fixed plate (4) from its guides;
4) remove the internal parts from the floating body
(5) using short bursts of compressed air through the
brake fluid duct to facilitate expulsion of the pistons
(6).
5) Check:
- that the plates and the body are undamaged and in
good state;
- that the cylinders of the floating body of the caliper
are not scratched or eroded otherwise replace the
entire caliper;
- that the guides of the fixed plate are not scratched
or eroded, otherwise replace the plate;
- that the pad holder is working.
Warning - Each time the calipers are overhauled,
all sealing components must be replaced with new
ones.
Pad holder
1.
brake pad retaining screws
2.
reaction plate fixing screws
3. opposing plate
4. fixed plate
5. floating body
6.
pistons
7. piston rings
8. guide protection rubbers
9. pad holder
10 pads
7 - 6
Refitting
Proceed as follows:
1 ) insert the pistons (6) complete with seal rings (7) into
the body;
2) fit the guide protection rubbers (8) and refit the fixed
plate (4);
3) mount the opposing plate (3) and tighten the screws
(2).
4) insert the pad holder (9) and the pads fixing them with
the relative screws;
5) position the caliper on the disc and lock it to the
upright by tightening the retaining screws;
6) lock the union of the hose on the caliper to the
specified torque.
Caliper to support: 20 ÷ 25 N-m
Oil union: 15 ÷ 25 Nm
Operation
The caliper used is of the floating type.
It exploits the principle of action and reaction to obtain
the thrust on both pads.
The body and the opposing plate, which are machined
together, can move axially in relation to the fixed plate,
which forms a single unit with the upright.
Pressure causes the pistons to force the pad against
the disc, and in doing so cause the opposing plate to
press the other pad against the disc.
COMPONENTS
07 005