Service Manual

29
4. Removal and Replacement of Evaporator
NOTICE
• Always install a new drier every time the sealed refrigeration system is opened. Do
not replace the drier until after all other repair or replacement has been made.
• When brazing, protect the drier by using a wet cloth to prevent the drier from
overheating. Do not allow the drier to exceed 250°F (121°C).
1) Close the water supply line shut-off valve.
2) Move the control switch to the "DRAIN" position.
3) Allow the water system to drain for 1 minute.
4) After all of the water has drained, move the control switch to the "OFF" position.
Unplugthe appliance from the electrical outlet.
5) Remove all ice from the storage bin.
6) Remove the top panel and rear panels. See Fig. 4.
7) Remove the spout and packing.
8) Remove the seal bolts securing the extruding head and evaporator ange.
NOTICE! Discard existing seal bolts after removal. Seal bolts must be replaced
once removed because seal material is one-time use only.
9) Grasp the cutter and carefully lift out the extruding head and auger. When pulling out the
auger, the upper part of the mechanical seal should come out with it.
10) Disconnect the reservoir outlet hose from the evaporator.
11) Remove the evaporator condensate drain pan.
12) Install a temporary tap-line valve on the high side, then recover the refrigerant and store
it in an approved container.
13) Disconnect the inlet and outlet tubing.
14) Remove the socket head cap screws securing the evaporator to the lower housing.
15) Lift off the evaporator.
16) Inspect the mechanical seal and O-ring prior to installing the new evaporator. The
mechanical seal consists of two parts. One moves along with the auger, and the other
is xed on the lower housing. If the contact surfaces of these two parts are worn,
cracked or scratched, the mechanical seal may cause water leaks and should be
replaced. Instructions for removing the mechanical seal and lower housing are located
later in this procedure.
17) Make sure the lower mechanical seal and the O-ring are in place, then place the
evaporator assembly in position. Secure the evaporator to the lower housing using the
socket head cap screws.
18) Replace the tap-line valve with a proper, permanent access valve.
19) Remove the drier, then place the new drier in position.
20) Braze all ttings while purging with nitrogen gas owing at a pressure of 3 to 4 PSIG.