Mercedes-Benz W123 rear window removal and seal replacement
How do you remove the W123's rear window intact for a seal replacement?
1. Remove the interior trim and plastic pieces and the rear window heater wires. 2. Remove the old seal starting from the middle with a screwdriver or a knife. 3. Push the glass out evenly from the inside, and ask another person to catch the glass. Do not use force.
How do you fit a new rear window seal?
1. Fit the new seal onto the edge of the glass. 2. Put a thin pulling cord in the seal channel, for example a venetian blind cord. 3. Lubricate the seal with pine soap. 4. Pull the cord from the inside while another person presses the glass into place. An old seal easily leaks again, so replace it with a new one.
Why does water drip into the boot from around the rear window seal?
In each lower corner of the seal channel there should be a hole of about 5 mm, through which water that has got under the seal drains out. If the hole is missing, drill it while the glass is out. If water drips into the boot in the rain, the seal has usually failed.
Is sealing compound needed under the rear window?
The W123's windows have no factory sealing adhesive, so you do not necessarily need to scrape off the old compound. If it leaks after fitting, use proper glazing compound. Silicone is not suitable for this.