Disassembly Of The Piston Unit - Supports - Seals - Pratissoli MK Serie Manuel De Réparation

2.2.3 Disassembly of the piston unit – supports – seals
The piston unit requires preventive checks as indicated in the
preventive maintenance table in the Use and maintenance
manual.
Maintenance is limited to visual inspection of any drainage
from the hole present on the lower cover. If abnormalities /
variations on the outlet pressure gauge or dripping from the
drainage hole circuit are detected, the seal pack will have to
be checked and replaced.
Proceed as follows to remove the piston units:
To access the piston unit, unscrew the M16x180 screws and
remove the head.
Remove the head taking care to avoid hitting the
pistons
Disassemble pistons unscrewing the fixing screws (pos. ,
Fig. 111).
Remove the piston from the seal support and check that
its surfaces do not present any scratches, signs of wear or
cavitation
Remove the upper inspection cover, unscrewing the 4 fixing
screws (pos. , Fig. 112).
Manually turn the shaft in such a way to bring the 3 pistons to
the top dead centre position.
Insert the buffering tool code 27516600 between the piston
guide and the piston (pos. , Fig. 113).
Turning the shaft, have the piston guide move forward so that
the buffer, moving ahead, can expel the seal support and the
entire piston unit (pos. , Fig. 114).
Fig. 111
Extract the seal support unit and the buffering tool.
Remove the seal support bottom O-ring should it remain
inside the pump casing (pos. , Fig. 115).
Fig. 112
61
Fig. 113
Fig. 114
Fig. 115