Cashco 8900 - Manual (Page 8)

8 IOM-8900 Series
Model 8940:
A. Inspection/Replacement of Vacuum
Pallet
Diaphragm:
1. Remove cap screws (28) from the weather
hood (11) and lift off upper spring canister (15).
Measure the length of the pallet stem (21), top edge
of stem to the top surface of the upper spring button
(14). Record this value. It will be required during re-
assembly to reset the vacuum range spring pressure
prior to installation.
Length of pallet stem ________
NOTE: DO NOT allow vacuum pallet assembly
(18) to fall as disassembly continues.
2. Rotate each nut (25) CCW one at a time to
remove and to release the compression of the spring
(16). NOTE: May need to grasp a section of the
threaded stem (21) with soft-jawed pliers to prevent
rotation of the pallet assembly (18). Maintain grip
on stem (21) while carefully lowering vacuum pallet
assembly (18) to rest on work surface below.
Lift up to remove upper vacuum spring button (14)
and spring (16).
NOTE: If vent was not supplied with a fl ame screen
(5) remove lower spring button (14) and lower spring
canister (13). If vent included a fl ame screen, before
removing button (14) and canister (13), draw match
“marks” between fl ange face of the lower spring
canister (13) and weather hood (11).
3. Lift handle (70) up to raise the weighted
pallet assembly and remove the vacuum pallet
assembly (18).
4. Place threaded end of pallet stem ( 21) in a
soft-jaw vise with pallet (18) face up.
5. Remove the cotter pin (56), nut (24), lock
washer (23), and the fl at washer (22).
6. Remove vacuum pallet (18) and diaphragm
(19). Clean pallet (18), especially the pallet groove
and inspect for nicks or sctatches. NOTE: Vacuum
pressure set point will dictate the quantity and stack
orientation of diaphragms. Record diaphragm’s
stack orientation for re-assembly.
WARNING
SPRING UNDER COMPRESSION. Relieve spring
com pres sion per following steps. Failure to do
so may result in fl ying parts that could cause
personal injury.
7. Install new diaphragm(s) (19) over short
threaded end of stem (21) onto retainer plate (20).
Apply a light coat of TFE paste on the top surface
of the last diaphragm (19) around the edge of the
center hole.
8. Place vacuum pallet (18) with the machined
groove facing down on the diaphragm (19). Apply a
light coat of TFE paste to short threaded end of stem
(21).
9. Install fl at washer (22), lock washer (23)
and nut (24) onto the protruding threads of the stem
(21). Use a torque wrench to tighten nut to 15 ft-lbs.
10. Insert cotter pin (56) thru small hole in the
stem (21) and wrap prongs around stem.
B. Vacuum Seat Ring Replacement -
For ERV with Counter Weight Design:
CAUTION
Use overhead support and sling to secure Counter
Weight. Failure to do so may result in falling parts
that could cause personal injury.
1. Attach sling and overhead support around
counter weight (58). Remove cotter pins (57) and
slide cables (17) off ends of pin (50).
2. Pull pin (50) out of pivot arm assembly
(46), spacers (51) and weight arm (47). Set coun-
ter weight assembly and parts aside.
3. Rotate nuts (55) CCW and remove. Push
hinge pin (52) through pivot arm assembly (46).
Lift pallet and vent hood assembly up to remove
from fl ange seat (1) assembly.
4. Proceed to Step D. or E.
C. Vacuum Seat Ring Replacement -
For ERV with Stack Weight Design:
1. Rotate top nuts (36) CCW and remove
nuts, lock washers (68) and fl at washers (67).
2. Lift up to remove stack of pressure weights
(64). Maintain stack orientation, do not remove or
add any weight that will change the factory caliba-
rated pressure setpoint.
3. Rotate nuts (55) CCW and remove. Push
hinge pin (52) through pivot arm assembly (46).
Lift pallet and vent hood assembly up to remove
from fl ange seat (1) assembly.