Back Window Glass: Service and Repair
Rear window, removing and installingGeneral
The rear window is secured to the convertible top with a zipper. To seal the joint, the "poly-glass" widow is secured to the fabric surrounding the window with an adhesive that is heat activated. A heating wire is set inside the adhesive joint and the adhesive can be activated, when replacing the window, with a 12 V power supply. Current of 26 amps is required.
Note: VAG 1742 rear window installation tool is required to install poly-glass window.
Removing
• Convertible top completely free of tension
• To relieve tension, open convertible top as shown and support in position to prevent it from dropping down. Distance -A- is approx. 350 mm (14 in.)
- Bend out terminals on end of heating wire (arrows) between zipper and fabric on left side of window toward bottom.
Note: The illustration shows the convertible top with the support bar pivoted upward.
CAUTION! Always make sure that the ends of the heating wire are not twisted together before connecting to the power supply. A short circuit could occur causing burns to the convertible top fabric.
- Connect power supply cables from VAG 1742 and allow adhesive to heat up for about 2 minutes.
Note: This illustration shows the power supply cables with the inside part of the rear window installation tool already in place. The tool must not be attached when removing the rear window.
- Disconnect power supply cables.
- Separate edge of fabric from rear window at bottom-center.
- Open zipper using suitable plastic tool.
- Pull rear window out of zipper all around window opening.
Note: Adhesive residue does not have to be removed from the convertible top fabric if the surface is smooth (no lumps).
Installing
- Align beginning and end of zipper together exactly and close zipper.
CAUTION! If the zipper is more than 2 teeth out of alignment it will cause a large amount oftension, especially at the corners of the window This can cause the window to melt and tear away when the wires are heated.
- Thread connecting wires between zipper tape and fabric.
CAUTION! When the ends of the wire are threaded through the seam on the convertible top, there must be a distance of at least 2 stitches between them to prevent them from becoming twisted together and causing a short circuit when the power supply is connected.
- Close zipper and remove zipper slide.
- Insert inside part of rear window installation tool between convertible top fabric and rear cross bar (arrow) on both sides.
- Center rear window installation tool in window opening.
- Attach retaining brackets at top left and top right between convertible top fabric and upper cross bar and secure with wing nuts.
• Center support of rear window installation tool must be braced with its base on rear seat.
- Attach outside part of rear window installation tool on convertible top and center within window opening.
Note: The convertible top is shown removed for a clearer illustration. It is not necessary to remove the convertible top when replacing the rear window
- Hook tensioning belt hooks from VAG1742 on both sides of convertible top frame.
- Position tensioning belt over outside part of rear window installation tool.
Note: To prevent damaging the paint work, install a piece of cardboard or similar material between the rear body side panels and the convertible top where the belts are attached.
- Thread belt into tensioner mechanism.
- Operate tensioner lever to tension belt (arrow).
Note: To release the tensioner belt, pull the center part of the tensioner upward and press the operating lever fully forward.
Checking pressure on joint
• Outer frame of VAG1742 rear window installation tool must be in uniform contact with convertible top around circumference of window.
- Using 0.5 mm (0.020 in.) thickness feeler gauge -1-, check pressure on joint around circumference of window.
Note: If the inside part of the frame is not in uniform contact with the convertible top all around the circumference when tension is applied to the outside frame, bend the inner frame accordingly.
Bending inner frame
- Bend inner frame to shape (arrows) if upper cross bar loses tension.
Sealing poly-glass window to convertible top
CAUTION! When the belt is tensioned, make sure that the outer part of the rear window installation tool is in contact with the convertible top fabric all around the window opening so that it presses the fabric onto the poly-glass rear window.
- Connect power supply cables from VAG 1742.
CAUTION! Make sure that the ends of the heating wire are not twisted together before being connected to the power supply. A short circuit could occur causing burns to the convertible top fabric.
- Switch on power supply to activate adhesive.
- Switch off power supply after 2 1/2 to 3 minutes.
- Let adhesive cool down for 20 minutes with VAG 1742 rear window installation tool in place on convertible top.
- Remove rear window installation tool.
- Cut ends of wires down to approx. 20 mm (3/4 in.) and insert securely between fabric and tape of zipper.
- Test for water leaks.
Note: If water leaks occur around the rear window attach all components of VAG 1742 rear window installation tool again and connect the power supply cables.
- Apply extra pressure between outer and inner parts of rear window installation tool in area of water leak.
- Disconnect power supply cables after 2-1/2 to 3 minutes.
- Let adhesive cool down for 20 minutes with rear window installation tool VAG 1742 in place.
- Remove rear window installation tool and retest for water leaks.