Cover Brake Cylinder B4 Automatic Transmission, Replacing

Cover brake cylinder B4 automatic transmission, replacing

Note! As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information is always correct.

Preparatory work

Removing components
Allow the transmission to cool. It is easier to remove the cover if the transmission is cold.

Remove:
- the left front wheel
- the splash guard under the engine.

Cleaning the cover




Locate the cover for the B4 brake.
Thoroughly wash and blow dry the area around the cover. Use cleaning agent, P/N 116 1721.

Removal

Removing cover




Install a screw (M10x80) as illustrated.
Use a heavy duty screwdriver and the screw as a lever to press the cover in a few times.
Remove the snap ring.

Removing cover, continued




Place paper on the sub-frame under the cover to absorb any oil and to catch the piston if it slides out of the transmission.
Remove the cover. Carefully work it out using pliers.

Note! Take great care when removing the cover so that the piston does not fall out. Then extract the piston.

Check the groove for the snap-ring to ensure that there are no burrs which could damage the O-rings. Remove any burrs using a fine sandpaper. Clean the cylinder thoroughly.

Checking the cover




If the washer (1) has come away from the cover, this accounts for the symptoms outlined in the background section.

Installation

Replacing the cover




Replace the O-ring on the piston
Install the O-rings on the cover.
The illustration shows the order of installation.

Note! Do not let the piston fall to the floor. If the piston falls to the floor, it must be checked thoroughly for damage.

Caution! The piston cannot be replaced. The transmission is calibrated using this piston. A piston from another transmission cannot be used.The entire transmission must be replaced if the piston is damaged.

Installing the snap ring




Press in the cover so that it passes the groove for the snap ring.
Install the snap ring.
Check that the snap ring is seated in its groove.
Remove the screw.

Adapting the control module
Connect the VIDA station to the car.
See VIDA, Vehicle communication, Automatic transmission, Adapting the control module.
Adaptation: Because this repair only affects 3rd and 4th gears, the adaptation does not need to be reset.
Start the engine. Allow the engine to idle.
Activate Adaptation Mode. Ignore the instruction to warm up the transmission first. When "Adaptation Mode" is activated, "Function run" will be displayed in the gray window in VIDA.

Note! Do not switch off the engine.

Disconnect the VIDA station. Test drive the car as described below.
"Transmission fluid temperature too high" will not be displayed and the general warning lamp will not light until the temperature has reached 65°C.

Finishing

Checking the function of the transmission
Start the test drive immediately. Drive at a steady speed, even while the transmission is cold.
Shift from 2nd to 3rd gear at different engine speeds until the quality of the gear shift is satisfactory. This may be difficult in the beginning, because air will have entered the system during the repair work.
Then shift from 4th to 3rd at a steady speed until the shift quality is satisfactory.
To speed up the adaptation, the shifts from 2-3, 3-4, 4-3, 3-2 can be made with the pedal depressed further.
When the transmission temperature reaches 65°C, the warning triangle in the combined instrument panel will light each time an "approved" shift is made.
Check the oil level. Check that there are no oil leaks.