Image above courtesy of Mastercool

©DenLorsTools.com Summary: This article has an excerpt from the Mastercool 69788-A pdf manual that outlines installing the replacement filters. Replacing the Dryer Filters is now necessary to meet the SAE J-2788 requirements for adequate moisture and contaminant removal. Keep in mind this is not something that the AC machine manufacturers are requiring, it is required to comply with the SAE J-2788 mandate. That’s why all the machines no matter which brand that are SAE J-2788 compliant, which includes all of them manufactured now, will require the replacement of filters every 150 pounds recycled. A code is required that helps ensure that the filters were actually replaced.

Replace the filters when the machine alerts you. Replace the filters only with Mastercool part numbers: 69788-FLTRPK. When changing the filters you will need a filter code. To obtain a filter code, please call Mastercool Inc. Technical Service at
888-825-6989.
LOCK OUT: If you are changing the filters because of the Second Service alarm (see page 9) and has locked out 69788, then a filter code will be needed to re-set 69788. Before changing the filters, call Mastercool Inc. Technical Service at 888-825-6989
to get the filter code.
NO LOCK OUT: If the filters are being changed at an unscheduled time, no filter code will be needed to continue operating 69788. Only when the machine reaches the pre-programmed recovery quantity of 132 lbs. will it lock out. Once the machine is locked out, the filter code will be needed to re-set the 69788. (See LOCK OUT)
To change the filters, proceed as described below (refer to Fig. 12):
1) Disconnect the machine from the electrical supply.
2) Wear protective gloves and glasses.
3) Remove the rear plastic cover from the machine (6 screws.)
4) Close both of the valves on top of tank.
5) Close the valve (Fig. 12-1) under the filter (Fig. 12-4.)
6) Connect the low pressure quick-connect coupling to the male connector
(Fig. 12-2) under the filter (Fig. 12-4.)
7) Connect the machine to the electrical supply and turn the machine on.

8 ) Put in the filter code. (Only if locked out) To put in the filter code, you will need to use the down arrow key to move the cursor to the next character. To input a letter continue to press the same number with the corresponding letter until the desired letter appears. Once the entire code is showing on the screen, press the ENTER key use the down arrow key to move the cursor to the next character. To input a letter, FIG. 12 continue to press the same number with the corresponding letter until the desired letter appears. Once the entire code is showing on the screen, press the ENTER key use the down arrow key to move the cursor to the next character. To input a letter, FIG. 12 continue to press the same number with the corresponding letter until the desired letter appears. Once the entire code is showing on the screen, press the ENTER key.

9) Using Assisted Procedure, start a recovery operation (NOTE: the valve under the low pressure filter [Fig. 12-3] should be open).
10) When oil draining is reached, immediately close the valve (Fig. 12-3) under the filter (Fig. 12-5) and turn the machine off.
11) Disconnect the machine from the electrical supply.
12) Disconnect the low pressure quick-connect coupling from the connector (Fig. 12-2) under the filter (Fig. 12-4).
13) Replace the filters. IMPORTANT: The filter replacement must be performed as quickly as possible in order to avoid possible contamination by
moisture in the ambient air.
14) Open the valve (Fig. 12-1) under the filter (Fig. 12-4) and the valve (Fig. 12-3) under the filter (Fig. 12-5).
15) Open both valves on top of the tank.
16) Connect the machine to the electrical supply and turn the machine on. (Leave the rear cover off at this time)
17) Press start when the machine displays “RECOVERY PROCEDURE INTERRUPTED, START: TO CONTINUE.”
18) Press reset when the machine displays “ERROR SYSTEM EMPTY.”
19) Tank charge about 1 lb (-500g) of refrigerant to charge the machine circuit.
20) While the machine is recovering, use an electronic leak detector to check the seal on the connections that were opened to replace the filters. Re-tighten if necessary.
21) Turn the machine off and replace the rear plastic cover on the machine. (6 screws)
22) The machine is now ready for normal use.

Mastercool 69788-A full pdf

69788-FLTRPK