Heidolph VAC control automatic - Manual (Page 59)

59
E
Loosen 4 ea. machine hex-recessed bolts on pump heads
and lift off upper half (lid with internal part)
 Never attempt to loosen parts with sharp tools
(screwdriver), use rubber hammer or compressed air
instead.
To inspect valves carefully detach lid from internal part;
denote location of valves and remove valves.
 Replace damaged valves.
Remove contamination with cleaning agent.
Inspect diaphragm for damage, replace on condition. To
this end remove data plate with 4 ea. Phillips screws.
Replace diaphragm:
Loosen diaphragm back-up disc with special tool.
Check for shims; arrange shims by cylinder and re-install
same number of shims.
 Insufficient number of shims: pump won't be able to
reach final pressure; too many shims: pump running
noisy.
Install new diaphragm between back-up disc with square-
head bolt and back-up ring.
 Caution: light-colored side of diaphragm points towards
cocking disc.
Install cocking disc, diaphragm, and back-up ring with
piston rod; use special tool.
 Make sure square-head bolt is properly seated in the cut-out of back-up ring.
Install pump heads:
Turn eccenter until piston rod reaches a position that
allows diaphragm to be located in the center of the
diaphragm and smoothly on mating surface of the
housing's cut-out.