The decision to re-paint or install aluminum siding to improve or maintain your house is an important one. Selecting and caring for the appearance and efficiency of your home-away-from-home - your truck cab - also requires analysis.
A 1993 survey of fleet managers and drivers by The Maintenance Council (TMC), part of the American Trucking Associations, Alexandria, Va. indicated that some of the cab maintenance problems fleet owners experience had not sufficiently improved in the 10 years since the last survey was taken. [See "Cab Construction Problems" page 268].
However, proper spec'ing and maintaining the cab body, cover, suspension and components mounted to the cab will improve cab appearance, ride, life and up-time.
The Body Caring for the cab's body includes adjusting the door strikers or replacing worn striker pins so that doors do not vibrate in and out. Lubing these parts and also the hingepins will ensure a quiet, smooth door operation and a longer life. Also, the deterioration of door seals and window felt is not always readily noticeable. Replace these parts when they are cracked or worn, if the door or window does not seal tightly, or if the door locks can't be adjusted. Seals and felt may need to be replaced once or twice during the cab's lifetime.
When cabs and sleepers are separate structures, tighten all fasteners at the connecting point once a year.
Also, check all high-stress areas of the cab annually, particularly the structural areas around each mounting point. This is so that developing cracks can be repaired before vibration causes damage.
In addition, the cab body's annual inspection should include checking large flat panels carefully to search for stress lines. These can be difficult to see, so check corners and cutouts.
Also, check the beads of sealer that may have run into the seams between large metal panels on the assembly line. If heat and sunlight shrink the bead, moisture can get in and cause rust. If this happens, replacement sealer may be necessary.
Suspension and Mounts Vibration, which causes problems on nearly every part of the truck, is dampened and controlled with springs, mounts and shock absorbers. All of these absorb unwanted energy and convert it to heat. Managing this energy requires you to confine motion and keep these components in good condition. To prevent motion from damaging the cab structure, make sure there are no loose fasteners, worn bushings or mounts, or fatigued/worn springs or shock absorbers.
Protect the seat and avoid bottoming out by maintaining the correct height adjustment, keeping the shocks in good condition, lubing all moving parts and tightening mounting bolts. Many times, shock absorber problems go unnoticed because deterioration is gradual. When shocks are working properly, vibration disappears almost immediately after a bump. When the ride becomes uncomfortable, check the cab shocks for oil leakage, a clue that shocks are bad. Also, it's critical that cab rear suspension mounting bolts are tight and in position. Air springs also should be in good condition.
In addition, inspect lateral control rods periodically, particularly when you hear or feel impact loads. All mounting bolts and nuts must be tight. Replace bushings that no longer fit snugly inside the end of a control rod, or if the hole at its center becomes elongated.
Tighten all cab mount fasteners, but if they can be rotated, retorque them. If these bolts loosen, the cab will bounce on the rubber isolator, causing impact loads on both it and on the cab. Check bolts annually on most trucks, but more frequently if the truck travels on hard surfaces because clearances of more than 1 inch can develop with repeated shock. Similarly, if the isolator has been deformed, it will lose its resilience, and should be replaced. An isolator should last approximately 350,000 miles.
Lateral motion is controlled by front cab mounts. If the cab becomes unstable, inspect and repair these mounts.
In addition, there are two cab mounted components to watch - hood and radiator mounts, which must be maintained by inspecting and tightening loose fasteners and replacing deformed isolators, and exhaust system mounts, which require periodic inspection.
Chassis Suspension On the chassis, replace shocks when they start to bottom out or when cab suspension is in good condition but you still can feel repetitive motion following a bump.
Check shocks for oil leakage, and inspect the isolators in shock ends for cracking, splitting or elongated holes. Use the same inspection for tracking rods on the suspension and replace isolators, if necessary.
Multi-leaf springs should have no cracked leaves, and all bolts fastening the leaves together should be torqued properly. Isolators in the springs' ends should be checked for deformation. Sagging and fatigued spring packs should be replaced.
Drivetrain vibration can weaken the cab, so engine and transmission mounts must be in good condition. Tighten mounting bolts approximately every 300,000 miles and look for cracked rubber, which indicates trouble. Driveshaft U-joints also can cause problems and should be lubed every 15,000 miles or less until old grease is purged.
Keep proper air suspension ride height and inspect for leaks. Height control valves should be in good repair and properly adjusted.
Paint and Finishes While some original equipment manufacturers believe clearcoating is unnecessary, spec'ing a clearcoat on top of the paint can enhance and preserve the look of the finish, particularly if loads are corrosive and damaging.
Some manufacturers will supply truck operators with premium paint or finishes, including a polyurethane product that offers high resistance to ultraviolet radiation, chemical deterioration and abrasion.
Clearcoating also is helpful if environmental regulations limit truck washing. It will help protect the finish from salt, dust, dirt, acid rain and ultraviolet light. Dirt, encrusted salt, soil and grime can corrode the finish, and the longer they are there, the more damage they do. If possible, wash the truck every five days.
Keep in mind that all cleaners are not equal, and it is critical to select the most effective one. On average, it's best to clean with frequent washing and a mild liquid soap solution. Many products also are good for brightening an old, faded paint job. However, these should not be used routinely, because they can remove the gloss.
According to Freightliner, Portland, Ore., to protect and extend the life of your new vehicle's finish:
* During the first 30 days, rinse the vehicle frequently with water. If it is dirty, use a mild liquid soap. Do not use detergent or anything abrasive. Brushes, chemicals and cleaners may scratch the finish.
* Do not wax the vehicle during the first 120 days.
* Avoid washing the vehicle in the hot sun.
* Always use water. After the cab is completely washed, dry it with a towel or chamois.
* Do not dust painted surfaces with a dry cloth because it will scratch the paint.
* Do not use a scraper to remove ice or snow from a painted surface.
* Wax the finish regularly to prevent damage. If the finish has dulled, remove oxidized paint before waxing using a cleaner specifically designed for this purpose. Also, remove all road tar and tree sap before waxing. Use a quality cleaner or cleaner-polish, and polishing wax.
* Rinse diesel fuel or antifreeze from painted surfaces with water immediately.
* Touch up any nicks or other damage to prevent rust.
* Park the vehicle under shelter whenever possible.
* Wash unpainted fiberglass parts monthly with a mild detergent, such as dishwashing liquid. Avoid strong alkaline cleansers and always apply a wax specifically designed for fiberglass.
* Keep chrome parts clean and protected to prevent rust, particularly during the winter or around salt air. Wash chrome with clean water, a soft cloth or sponge, and mild detergent. Sponge gently, then rinse. If necessary, use a non-abrasive chrome cleaner to remove stubborn rust or other material. Do not use steel wool. After cleaning, apply a coat of polishing wax to the surface. Never use wax on parts that are exposed to high heat, such as exhaust pipes.
* Wipe the dashboard periodically with a water-dampened cloth and a mild detergent. Do not use vinyl cleaners on the dashboard. Some of these cleaners contain compounds that are damaging to the dash and may cause it to crack.
Once you've spec'd the truck, you must care for its insides continually. It is important to ensure that materials, such as vinyl and velour are cared for properly. Here are some guidelines provided by Freightliner, Portland, Ore.
Vinyl To prevent vinyl upholstery from soiling, lightly brush or vacuum it frequently to remove dust and dirt. Waxing or refinishing improves soil resistance and "cleanability." Hard wax, such as automobile wax, may be used.
However, harsh cleaning agents can cause permanent damage to vinyl upholstery.
For specific problems such as:
* Ordinary Dirt - Wash the upholstery with warm water and mild soap, such as saddle or oil soap. Apply soapy water to a large area and allow it to soak for a few minutes. Then rub briskly with a cloth to remove dirt. This can be repeated several times as necessary. If dirt is deeply imbedded, use a soft bristle brush after applying the soap. If this does not work, use a wall-washing preparation, normally found in the home. Powdered cleaners, such as those used for sinks and tiles, are abrasive and must be used with caution because they can scratch the vinyl or give it a permanent dull appearance.
* Chewing Gum - Harden the gum with an ice cube wrapped in a plastic bag, then scrape it off with a dull knife. Remaining traces of gum can be removed with an all-purpose light oil or peanut butter.
* Tars, Asphalts and Creosote - These items stain vinyl after prolonged contact. Wipe them immediately and clean the area carefully using a cloth dampened with naphtha.
* Paint or Shoe Heel Marks - Remove paint immediately using an unprinted cloth, dampened with naphtha or turpentine. Avoid contact with non-vinyl parts of the upholstery. Do not use paint remover or a liquid-type brush cleaner on vinyl.
* Sulfide Stains - Sulfide compounds, such as those found in eggs and some canned goods, can stain after prolonged contact with vinyl. Remove stains by placing a clean, unprinted cloth saturated with 6 percent hydrogen peroxide over the spotted area. Leave the cloth on the spot for 30 to 60 minutes. For stubborn spots, leave saturated cloth on the area overnight. However, don't let the solution seep into the seams because it will weaken the cotton thread.
* Nail Polish and Nail Polish Remover - Prolonged contact with these substances causes permanent damage to vinyl. Blot immediately after contact. Do not spread the liquid during removal.
* Shoe Polish - Most shoe polishes contain dyes that penetrate vinyl and stain it permanently. Shoe polish should be wiped off as quickly as possible using naphtha or lighter fluid. If staining occurs, try the sulfide stain removal procedure.
* Ball Point Pen Ink - Ball point pen ink sometimes can be removed if it is rubbed immediately with a damp cloth, using water or rubbing alcohol. If this does not work, try the procedure used for sulfide stains.
If stains do not respond to any of the treatments described above, it is sometimes helpful to expose the vinyl to direct sunlight for up to 30 hours.
Mustard, ball point pen ink, certain shoe polishes and dyes often bleach out in direct sunlight, leaving the vinyl undamaged.
Velour As with vinyl, to prevent velour upholstery from soiling, lightly brush or vacuum it frequently to remove dust and dirt. Spot clean with a mild solvent, an upholstery shampoo or foam from a mild detergent. When using a solvent or a dry-cleaning product, follow the instructions carefully, and clean only in a well ventilated area. Avoid any product that contains carbon tetrachloride or other toxic materials. Pre-test a small area before cleaning. Use a professional upholstery cleaning service for extensive cleaning.
* Grease and Oil-Based Stains - Dampen a small absorbent cloth with dry-cleaning solvent or spot remover, then pat carefully from the outer edge to the center. Blot the spot with a clean, dry cloth, repeating this as necessary. Turn the cloth so that the stain does not redeposit on the fabric.
* Sugar and Water-Based Stains - Apply water-based detergent or cleaner, working in circular motions. Pat and blot as dry as possible; repeat, if necessary, before drying thoroughly.
* Chewing Gum or Wax - Harden the gum or wax with an ice cube wrapped in a plastic bag, then scrape it off with a dull knife. Excess wax can be absorbed by placing a thick white blotter over the wax and heating with a warm (not hot) iron. Remove the remainder by using the grease and oil-based stains procedure.
* Mildew - Brush the dry fabric with a soft brush, then sponge with detergent and blot. If the fabric is colorfast, dilute a teaspoon of bleach in 1 quart of cool water. Apply with a swab directly on the mildew stain. Dab repeatedly with clear cool water and blot dry.
Maintaining your cab properly - inside and out -will help ensure you a long life in your home-away-from home.