MAINTENANCE MANUAL
Speedster
page 29
When warm, the pressure needed for checking and adjustments can be supplied by the
pump.
Note
The group valve has a rating of 15 Bar. This means it will be pushed open when pressure
exceeds 15 bar. The group valve thus acts as a second safety, should the expansion
valve fail to open.
Check expansion valve
Materials needed
Spanner 13 mm, 16 mm, 21 mm
Allen key 5 mm
Wide screwdriver
Towel or sponge
Procedure when machine is cold
1.
Turn the machine “on”.
2.
Be sure the coffee water system is completely filled: water should excite
immediately from the group when the brew lever is moved downwards.
3.
Remove both left and right side panels and upper body panel. (When the outer
nut of the expansion valve is not too tight, there is no need to retain the
expansion valve such that the left side and upper body panels do not have to be
removed.)
4.
Turn outer nut loose from expansion valve with 16 mm spanner. Retain expansion
valve with 21 mm spanner. Let drain hose with short copper tube and nut dangle
to side.
5.
Check on right hand pressure gauge at what pressure the expansion valve starts
to drip. Have a towel ready to pick up the spills.
6.
If opening pressure is lower than 12 Bar, use a 5 mm Allen key to turn the set
screw inside the expansion valve clockwise (see figure 17).
If expansion valve does not start dripping when 12 Bar is reached, turn set screw
counter-clockwise until it does.
When the valve cannot be closed at 12 Bar, the sealing disk inside has to be
replaced (see below).
Figure 17. Showing detail of expansion valve and hexagonal opening in set screw. Drain
hose is removed from valve.
expansion valve
set screw
