VESPA GTS 250 I.E. Workshop Manual page 256

Braking system
1. Reservoir cap screw
2. Reservoir cap.
3. Diaphragm.
4. Bellows.
5. Sealing ring
6. Piston.
7. Gasket.
8. Spring.
9. Reservoir
Refitting
To refit, carry out the removal operations but in reverse order, observing the specified torques.
Locking torques (N*m)
Oil pipe joint to the pump: 20 - 25 Brake pump fixing screws to the handle bar: 7 ÷ 10 Nm
BRAK SYS - 16
Vespa GTS 250 I.E.