Table of contents: Safety precautions when performing… ↓ Additionally ↓
The cars of these models have a "universal body" design, where a floor panel with front and rear side beams is used (spars) frames that act as carriers for the rest of the car body parts, front and rear suspensions and other mechanical components. The windshield and rear window are glued in place. Some of the components are particularly vulnerable to accidents and can be removed and repaired or replaced. These include the hood, trunk lid, doors and front fenders. When installing, gaps must be maintained, otherwise, for example, the door will knock or increased wind noise will be observed when driving. The gap must be at least parallel along its length, i.e. the distance between the body parts must be maintained constant along the entire length. Deviations of up to 1 mm are permissible.
During the production process, the car body is completely galvanized. The external elements of the body have an electrolytic zinc coating, since this type of coating is technologically advanced when applying paint and varnish coating and is easily deformed. Internal and invisible elements of the body have cheaper hot-dip galvanizing. To increase corrosion resistance, all hollow parts of the body are additionally filled with wax, and a protective coating is applied to the bottom. Bumpers and wheel arch liners are made of plastic for strength and durability.
When disassembling and assembling, try not to damage the seals and anti-corrosion coating applied by the manufacturer.
Before working on the instrument panel, doors or any electrical equipment, remove the ground wire from the battery. To do this, read the notes in the subsection Removal and installation the battery and subsection Entering the radio code.
Safety precautions when performing bodywork
- When repairing the body, spot welding should be used. Only if electrodes cannot be brought to the welding site, welding in an inert gas environment should be used. Since the body is completely galvanized, the following safety measures must be taken:
- When carrying out welding or any other work involving the formation of sparks, be sure to disconnect the battery (positive and negative cables) and carefully insulate both terminals (–) and (+). When working near the battery, it must be removed.
Warning: When the battery is removed, the data from the electronic memory units is erased, in particular the radio receiver code. Without the code, the radio receiver can only be switched on by its manufacturer or an AUDI service station. Therefore, read the notes in the subsection Entering the radio code.
Warning: When welding galvanized sheets, toxic zinc oxide is formed. Therefore, it is necessary to ensure good ventilation of the workplace.
Warning: Increase welding current by 10, maximum 30%.
Warning: Use solid copper electrodes with high heat resistance (above + 400°C).
Warning: Clean the electrodes frequently and treat them to a contact surface diameter of 4 mm.
Warning: Increase the pressure on the electrode.
Warning: Increase the welding time. The time is correct if the welding spots are set without spatter.
Warning: Air conditioner parts filled with working fluid must not be welded or soldered with either soft or hard solder. This also applies to situations where there is a risk of heating air conditioner elements when welding or soldering other structural elements.
Additionally
Do not open the air conditioner cooling circuit, as the refrigerant may cause frostbite if it comes into contact with your skin.
When applying paintwork in a drying oven, do not heat the car to a temperature above + 80°C. Otherwise, the electronic devices of the car may be damaged. In addition, the pressure in the air conditioner increases, which can lead to the destruction of the system.
The protective coating of the car's underbody made of PVC is removed with a rotating steel brush or hot air at a temperature of up to +180°C using a spatula. Heating the PVC coating to a temperature above 180°C causes a chemical reaction and the formation of hydrochloric acid, which promotes active corrosion, and also produces harmful vapors.
(The original article is posted on the resource: AUDImanual)