Lincoln Corsair: Transmission Cooling - 8-Speed Automatic Transmission – 8F35/8F40 / General Procedures - Transmission Fluid Cooler - Backflushing and Cleaning

Special Tool(s) / General Equipment

Materials

Flushing

NOTE: The cooler bypass valve cannot be backflushed. Install a new cooler bypass valve when this procedure is complete.

1. NOTE: Use transmission fluid specified for this transmission. Do not use any supplemental transmission fluid additives or cleaning agents. The use of these products could cause internal transmission components to fail, which will affect the operation of the transmission.

   The transmission cooling system (cooler and lines) MUST be flushed every time the transmission is overhauled or replaced in order to minimize the likelihood of repeat repairs. It is mandatory that proper equipment and procedures be followed when flushing coolers/lines. The flushing equipment used MUST:
   
   • maintain fluid at 60°C (140°F) or above
     
   • pulsate fluid during cleaning
     
   • have a GPM flow meter
     
   • have twin magnetic filters
     
   • and have air purge capability before and after flushing.
     

1. If equipment meeting the specifications above is not available, the transmission fluid cooler and the cooler bypass valve should be replaced and the lines cleaned by hand.
   

1. Check and top off fluid level of the transmission cooling system heated flusher with transmission fluid.
   Use the General Equipment: Transmission Cooling System Heated Flusher
   Material: Motorcraft® MERCON® ULV Automatic Transmission Fluid / XT-12-QULV (WSS-M2C949-A, ) (MERCON® ULV)

1. Turn on the heater and allow the fluid in the cooling system heated flusher 15-30 minutes to heat up to 60°C (140°F) before using.
   

1. Disconnect the transmission fluid cooler tubes from the transmission.
   

1. Install the line adapters on the transmission fluid warmer inlet and outlet tubes.
   

1. Attach the cooler line flusher red line to the transmission fluid warmer inlet tube assembly. For the location of the transmission fluid warmer inlet and outlet tubes:
   Refer to: Transmission Cooling - Component Location (307-02A Transmission Cooling - 8-Speed Automatic Transmission – 8F35/8F40, Description and Operation).
   

1. Attach the cooler line flusher blue line to the transmission fluid warmer outlet tube assembly.
   

1. Follow the equipment instructions to purge the transmission fluid cooler tubes and transmission fluid warmer prior to starting the flushing procedure.
   

1. Allow the transmission fluid cooling system to backflush for 10-15 minutes, then flush the transmission fluid warmer in a normal flow direction for an additional 10-15 minutes.
   

1. If the transmission fluid cooling system heated flusher is equipped with an inspection micron filter:
   
   1. Remove and clean the Oberg 28 micron filter.
      
   2. Install the filter.
      
   3. Backflush the system for 5 minutes.
      
   4. Remove and inspect the filter.
      
   5. If debris/contamination is present on the filter, repeat step 10.
      

1. Follow the equipment instructions to purge the transmission fluid cooler tubes and the transmission fluid warmer.
   

1. Disconnect the cooling system heated flusher from the transmission-mounted cooler tubes.
   

1. Disconnect the transmission fluid cooler tubes from the cooler bypass valve.
   

1. Install the line adapters on the transmission fluid cooler inlet and outlet tubes.
   

1. Attach the cooler line flusher red line to the transmission fluid cooler inlet tube assembly. For the location of the transmission fluid cooler inlet and outlet tubes:
   Refer to: Transmission Cooling - Component Location (307-02A Transmission Cooling - 8-Speed Automatic Transmission – 8F35/8F40, Description and Operation).
   

1. Attach the cooler line flusher blue line to the transmission fluid cooler outlet tube assembly.
   

1. Follow the equipment instructions to purge the transmission fluid cooler tubes and transmission fluid cooler prior to starting the flushing procedure.
   

1. Allow the transmission fluid cooling system to backflush for 10-15 minutes, then flush the transmission fluid cooler in a normal flow direction for an additional 10-15 minutes.
   

1. If the transmission fluid cooling system heated flusher is equipped with an inspection micron filter:
   
   1. Remove and clean the Oberg 28 micron filter.
      
   2. Install the filter.
      
   3. Backflush the system for 5 minutes.
      
   4. Remove and inspect the filter.
      
   5. If debris/contamination is present on the filter, repeat step 19.
      

1. Follow the equipment instructions to purge the transmission fluid cooler tubes and the transmission fluid cooler.
   

1. Clean or replace the transmission-mounted transmission fluid cooler tubes as necessary if restrictions or a flow issue is found and install a new cooler bypass valve, if equipped.