Automotive Chemicals and Lubricants

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A number of automotive chemicals and lubricants are available for use during vehicle operation, maintenance and repair. They include a wide variety of products ranging from gasoline and motor oil to lubricants, cleaning solvents and degreasers, and protective sprays for rubber, plastic and vinyl.

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Operational Chemicals -

  • Gasoline, of course, is the most widely-used automotive chemical. See Fuel for a more complete discussion of gasoline.

    • See Safety Precautions related to gasoline.

  • Gas Additives perform several functions, depending on their chemical makeup. They usually contain solvents that help dissolve gum and varnish that build up on carburetor, fuel injection and intake parts. They also serve to break down carbon deposits that form on the inside surfaces of the combustion chambers. Some additives contain upper cylinder lubricants for valves and piston rings, and others contain chemicals to remove condensation from the gas tank.

  • Motor Oil is the lubricant formulated for use in engines. It normally contains a wide variety of additives to prevent corrosion and reduce foaming and wear. Motor oil comes in various weights (viscosity ratings) from 5 to 80. The recommended weight of the oil depends on the season, temperature and the demands on the engine. Light oil is used in cold climates and under light load conditions. Heavy oil is used in hot climates and where high loads are encountered. Multi-viscosity oils are designed to have characteristics of both light and heavy oils and are available in a number of weights from 5W-20 to 20W-50.

  • Oil Additives range from viscosity index improvers to chemical treatments that claim to reduce internal engine friction. It should be noted that most oil manufacturers caution against using additives with their oils.

  • Brake Fluid is specially formulated hydraulic fluid that can withstand the heat and pressure encountered in brake systems. Care must be taken so this fluid does not come in contact with painted surfaces or plastics. An opened container should always be resealed to prevent contamination by water or dirt.

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Lubricants -

  • Motor Oil (see above).

  • Gear Oil is designed to be used in differentials, manual transmissions and other areas where high-temperature lubrication is required. Use Hypoid 80w90 or 85w90, but don't use any with "GL5" standard on the bottle - it must be GL4 or GL3. The GL5 standard is bad for the bronze components inside the box - it gets corrosive when hot. The older GL4 and GL3 oils are not corrosive to bronze.

  • Chassis and Wheel Bearing Grease is a heavy grease used where increased loads and friction are encountered, such as for wheel bearings. balljoints, tie-rod ends and universal joints.

  • High-Temperature Wheel Bearing Grease is designed to withstand the extreme temperatures encountered by wheel bearings in disc brake equipped vehicles. It usually contains molybdenum disulfide (moly). which is a dry-type lubricant.

  • White Grease is a heavy grease for metal-to-metal applications where water is a problem. White grease stays soft under both low and high temperatures (usually from -100 to +190-degrees F), and will not wash offer dilute in the presence of water.

  • Silicone Lubricants are used to protect rubber, plastic, vinyl and nylon parts.

  • Graphite Lubricants are used where oils cannot be used due to contamination problems, such as in locks. The dry graphite will lubricate metal parts while remaining uncontaminated by dirt, water, oil or acids, It is electrically conductive and will not foul electrical contacts in locks such as the ignition switch.

  • Moly-Penetrants are used to loosen and lubricate frozen, rusted and corroded fasteners and prevent future rusting or freezing. Examples are Liquid Wrench, Kroil, etc. Our experience has shown Kroil to be very effective.

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Cleaners and Degreasers -

Examples include -

Note: Dave used both of these products when he refurbished is fuel tank and found them to be excellent.

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Rust Inhibitors -

  • POR-15 Rust Preventative Paint, touted to stop rust permanently.

  • Fisholene, an excellent product available in Australia and New Zealand (I haven't seen it in the U.S.).

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Maintenance/Repair Chemicals -

  • Mineral Spirits (odorless); also called petroleum spirits, white spirits, is a hydrocarbon solvent which has a flash point above 100F. Mineral spirits are used to remove grease from the outside of the engine and for cleaning of parts.

  • Carburetor Cleaner is a strong solvent for gum, varnish and carbon. Most carburetor cleaners leave a dry-type lubricant film which will not harden or gum up. Because of this film it is not recommended for use on electrical components.

  • Brake system cleaner is used to remove grease and brake fluid from the brake system, where clean surfaces are absolutely necessary. It leaves no residue and often eliminates brake squeal caused by contaminants.

  • Contact Cement is a neoprene-based adhesive in methyl ethyl ketone (MEK) solvent. It is good for bonding large, flat surfaces, such as carpet. It is usually applied by brush to both surfaces that will be bonded. See our Carpet Procedure for precautions and application instructions.

  • Gorilla Glue is another excellent adhesive that we have recently (May 2004) discovered. It is touted to be "the strongest glue in the world," and will bond to most anything. We have found it particularly useful in keeping the edges of the door trim vinyl tacked down on the inside of the door panels. It requires that the two materials beind glued together be clamped for 3-4 hours -- we've found that clothes pins work well on the door trim panels.

  • Methylene Chloride-based paint removers. Methylene chloride works very well for stripping paint, such as when preparing the car for repainting. It is soluble in water, which makes for easy cleanup. You should wear appropriate gloves, as methylene chloride is a severe eye and skin irritant and causes a burning sensation on contact. Methylene chloride is listed as a suspected human carcinogen.

  • Waxes and Polishes are used to help protect painted and plated surfaces from the weather. Different types of paint may require the use of different types of wax and polish. Some polishes utilize a chemical or abrasive cleaner to help remove the top layer of oxidized (dull) paint on older vehicles. In recent years many non-wax polishes that contain a wide variety of chemicals such as polymers and silicones have been introduced. These non-wax polishes are usually easier to apply and last longer than conventional waxes and polishes.

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Sealants -

  • RTV (Room-Temperature Vulcanizing) Sealant is one of the most widely used gasket compounds. Made from silicone, RTV is air curing, it seals bonds, waterproofs, fills surface irregularities. remains flexible. doesn’t shrink, is relatively easy to remove, and is used as a supplementary sealer with almost all low and medium temperature gaskets.

  • Anaerobic Sealant is much like RTV in that it can be used either to seal gaskets or to form gaskets by itself. It remains flexible, is solvent resistant and fills surface imperfections, The difference between an anaerobic sealant and an RTV-type sealant is in the curing. RTV cures when exposed to air, while an anaerobic sealant cures only in the absence of air. This means that an anaerobic sealant cures only after the assembly of parts, seating them together.

  • Thread and Pipe Sealant is used for sealing hydraulic and pneumatic fittings and vacuum lines. It is usually made from a Teflon compound, and comes in a spray. a paint-on liquid and as a wrap-around tape.

  • Fuel Tank Sealer.POR-15 Fuel Tank Sealer is an excellent product that will make your fuel tank last forever (according to John Connolly at Aircooled.Net.

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Miscellaneous Chemicals -

  • Anti-Seize Compound prevents seizing, galling, cold welding, rust and corrosion in fasteners. High-temperature anti-seize, usually made with copper and graphite lubricants, is used for exhaust system and exhaust manifold bolts.

  • Anaerobic Locking Compounds (e.g., Loktite) are used to keep fasteners from vibrating or working loose and cure only after installation, in the absence of air Medium strength locking compound is used for small nuts, bolts and screws that may be removed later. High-strength locking compound is for large nuts, bolts and studs which aren’t removed on a regular basis.

  • Weatherstrip Adhesive is used to bond weatherstripping around doors, windows and trunk lids. It is sometimes used to attach trim pieces.

  • Undercoating is a petroleum-based tar-like substance that is designed to protect metal surfaces on the underside of the vehicle from corrosion. It also acts as a sound-deadening agent by insulating the bottom of the vehicle.

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Disclaimer stuff: Rob and Dave have prepared this information from their own experiences. We have not assumed any specialised mechanical knowledge, but we DO assume that anyone using these procedures has at least some basic mechanical ability.

We hope you find this information useful, but we don't take any responsibility for anything which happens to you, other people, your VW or any other property or goods resulting from your use of these procedures.

Feel free to print off any of this information for your own use. If you intend to link this material to another site, reprint it, or in any other way redistribute it, please leave the information complete, including this disclaimer section, and provide a link to this Web site.

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Have fun fixing your VW - just keep them fweeming, OK?

Last revised 13 July 2004.