Cleaning the Cooling System

NOTE: Component identifier numbers used in the following illustrations relate to specific steps in the procedures below.

NOTE:
- After changing components or repairing the transmission internally, flushing equipment 87 91 824, or equivalent, should be connected to the transmission cooling system before the engine is started.
- It is not necessary to connect the flushing equipment if the transmission broke down due to engine coolant in the ATF fluid. The flushing equipment does not remove water from the ATF fluid.
- When the flushing equipment is connected to the cooling circuit, the direction of flow is reversed and contaminants are more easily loosened and good cleaning is achieved.





1. Install a new filter to the adapter plate before each flushing. Start by oiling the adapter plate sealing surface using automatic transmission fluid to ensure that the filter seal will move easily.





2. Disconnect the cooling hose from the back of the transmission.
3. Connect the cooling hose to the filter adapter.
4. Connect the hose from tool kit 87 91 824 between the filter adapter and the front of the transmission.
- On models with Turbocharger, the hose is most easily connected to the transmission from the underside of the car.
5. On all models, place the filter adapter and hoses beside the upper coolant hose and attach the assembly to the cooling hose using a cable tie. Do not bend the hoses.
6. Connect the return hose from tool kit 87 91 824 to the back of the transmission and connect it to the coolant hose using the long banjo bolt and domed nut.
7. Place the hose coupling on the front of the gear case so that it cannot drag on the ground.





Cars Without Thermostat And Air-Cooled Fluid Cooler
a. Flushing equipment not installed.
b. Flushing equipment installed.





Cars With Thermostat And Air-Cooled Fluid Cooler
a. Flushing equipment not installed.
b. Flushing equipment installed.





Only Cars With Thermostat
8. Connect the adapter plate cables to the temperature instrument in the car.
a. Disconnect the cable connection to the engine temperature sensor and plug in the sensor cable from the adapter plate.
b. Connect the adapter plate ground lead to the negative terminal on the battery.





All Systems
9. Fill the transmission with fluid, start the engine and check for leaks at the connections.
10. Test operate the transmission.
Cooling Circuit Without Thermostat
- Flush for 5 minutes with the selector lever to position D.
Cooling Circuit With Thermostat
- Run the transmission up to operating temperature with the selector lever in position D until the temperature gauge shows 100° C. The thermostat is then open.
All Systems
- With the car stationary, operating temperature can most quickly be achieved as follows:
a. Apply the foot brake and hand brake.
b. Set the selector lever to position D.
c. Run the engine at 1500 RPM until the temperature gauge shows 100° C. Allow flushing to take place for about five minutes after the thermostat has opened.

CAUTION: Before test driving, check that the engine radiator fan is working so that the engine does not overheat.