by HR Tech Publications Dept.

Have you checked your tires recently? Modern day tires are designed to last longer than ever before. However, without proper care and maintenance your tires will wear out in the half the time.

Tires are responsible for holding the motorhome up, getting it moving, changing directions and stopping. Tires play the key role in operation of the vehicle, yet when it comes to the day to day maintenance, they often become the most overlooked.

The fundamentals in tire care are air pressure, load distribution, road conditions, maintenance and service.

Information printed on the tire sidewall, coupled with the specs engraved on the manufacturers load weight sticker, is the official guidebook to achieve maximum tire use.

Air Pressure

The maximum tire inflation pressure is molded onto the sidewall of the tire. One of the simplest maintenance areas on your vehicle is checking tire pressures. Any reading registering four pounds under or over the official pressure is considered the wrong inflation.

A tire below the maximum tire inflation pressure is deemed underinflated. This type of tire will worsen fuel economy. Tires with low pressure will degrade vehicle handling, thereby causing the steering to get "mushy" and prevent the coach from rolling as well. Underinflation accelerates wear and requires replacing the tire sooner than necessary. Hitting potholes with decreased air pressure damages the wheel of the vehicle.

A tire inflated above the maximum pressure is termed overinflated. Excessive air pressure reduces the vehicle's forward traction for starting and stopping. Overall handling of the coach becomes sensitive to a harsher ride. Increased tire pressure creates uneven wear on tires. Overinflated tires become vulnerable to impact and contribute to blow outs.

Duals must be inflated equally. Rough roads naturally prevent the duals from working in concert and promote hastened wear to the inner duals. Increasing air pressure on the inner duals in an attempt to overcompensate for rough roads will only result in early fatigue of that tire as it endures the risks of overinflation. The only proper solution to excess stress on the inner duals is to closely monitor those tires and keep them adequately inflated.

Load

Following the manufacturer's weight ratings for your coach is imperative to the life of your tires. Listed on the vehicle sticker is the maximum allowable rate for Net Carrying Capacity (NCC). This figure tells you how much weight can be added to the coach after purchase. Keep the NCC restriction in mind when loading the vehicle for travel. Tires will not perform properly on vehicles exceeding the Gross Vehicle Weight Limit.

In addition to staying within the manufacturer's weight restrictions, the load of the vehicle must be distributed evenly. Placing excessive load on one particular side of the vehicle will cause unnecessary wear and tear on the tires.

Physical weighing of the coach upon completion of loading is necessary. Public truck scales are simple to use and available at most large truck stops. Simply take the fully loaded coach to the scales and weigh each corner of the vehicle individually for accurate readings on the load distribution weights.

Keep in mind that loads change from trip to trip and the coach should be re-weighed prior to embarking on a new journey.

Road Conditions

Repeated freezing and thawing of moisture that seeps through the pavement creates potholes. Driving the vehicle into a pothole can throw the vehicle's front end out of alignment, damage the wheels and cause internal tire damage undetectable from the outside.

Do not brake during pothole impact. Instead, apply the brakes before hitting a pothole and release the brake prior to impact. Braking during impact sets up the tire and wheel assembly for a solid hit against the edge of the hole. Less severe damage occurs when a tire is rolling than when it is skidding over the hole during braking.

Wet roads can take up to four times the normal stopping distance than a dry road. As water accumulates on the road, and speed increases over 40 miles per hour, tires with shallow tread risk hydroplaning.

Leaves have a tendency to retain moisture and create a slippery tire surface. Additionally, large amounts of leaves can conceal other road hazards. Even when road conditions are dry it is wise to decelerate when driving over excess leaves.

Driving habits decree how appropriate the tire will wear. Avoid excessive speed, fast turns on curves and corners, driving over curbs, hitting road obstructions, fast stops and starts.

Regularly inspect the duals for foreign objects that lodge in between. Be aware of "crowned roads" which are causing the inside duals to support more of the load. When driving over these types of surface increase pressure checks of the inside duals appropriately.

Properly inflated tires are your best defense against rough roads.

Maintenance

Proper tire maintenance means being frequent and thorough. A proper air gauge is your best weapon against short tire life. Equip your vehicle with a heavy-duty truck gauge and keep it handy for daily use. Have your gauge checked against a repair shop's master meter once a year. Don't depend solely on gauges located at fuel stations, which are exposed to adverse weather and abuse.

Valve stem caps must always be reinstalled after checking the tire pressure. If the cap is missing, dirt and dust will get into the valve stem and dirt can lodge open the pressure valve to create an air leak site.

Always check the air pressures on a cold tire. Heat generated during driving increases air pressure above the proper cold inflation pressure. Never bleed air from a hot tire. This could result in dangerous underinflation.

Do not test tire pressures with a stick. Tests have shown that using a stick to thump a properly inflated tire will have the same result as using the same stick to thump a tire with 25% loss of air pressure.

Normal and natural aging of a tire will cause the rubber to crack, resembling a desert floor. If the tire develops wide cracks, large enough to slide in a penny sideways, the tire is showing unnatural wear.

Visual inspections of the tires can reveal if the tire is aging appropriately. Inspect the edge of the tire where the tread meets the sidewall. All of the tread should wear evenly. If the tread looks untouched (compared to the middle of the tire) the tire has experienced overinflation. If the sidewall is wearing as much as the tread, underinflation has occurred (or driving too fast around corners). If the inside is showing wear different from the outside, or the wear appears erratic, the tires may be experiencing alignment or balance problems. Wear discrepancies between the front and rear tires are normal.

Inspect the tire tread for wear, cuts, tears or bulges. Remove any objects caught in the tread. A bubble in the tire signifies air infiltration.

Closely examine the inner dual spacing to ensure separation between tires. Tires rubbing against other tires will rapidly increase deterioration.

Proper cleansing of tires is necessary to remove road grime and exposure to the environment. Wash the tire with mild dish liquid soap in a bucket of water. If you prefer to use a tire dressing, carefully follow the manufacturer's instructions. After applying the dressing, let the tire rest overnight and run your fingers over the surface the following day. If black substance rubs off you may be drawing out the natural oils used in manufacturing the tire and thereby decreasing the tire life.

Tires with uneven wear patterns can signal misalignment. The vehicle's feel of steering changes when misalignment occurs. Occasionally have a professional check your tires for misalignment. If misalignment is detected and corrected early enough you can extend the life of the tires.

Repair

The age of your tire is listed on the sidewall. As of the year 2000, the date of manufacture is displayed in four digits: first two denoting the month of manufacture; latter two the year. (Example: 0800 designates August of 2000.)

Tires over five years-old, or tires that show signs of unusual cracking, should be inspected regularly by a tire professional to determine if they should remain in service or be discarded.

Only specially trained persons should mount tires. Improper tire mounting can result in explosion of the tire and rim assembly.

Tire brands can be mixed on the steering axle, but it is imperative they are of the same size. Duals must always be replaced in pairs.

There are options available to repair a flat tire, but most will void the tire warranty. Patching, shaving and regrooving are not recommended for vehicles driving heavy loads at fast rates of speed.

Don't forget to maintain the spare tire. A stored tire also ages from the elements and can lose value without ever even being mounted.

If a blow out occurs avoid panic braking of the vehicle. Instead, slowly coast to a stop using light braking applications. Park the vehicle as far off the side of the road as possible. Be cautious of oncoming traffic when inspecting a flat tire. Position hazard markers appropriately within the vicinity of your vehicle and call for assistance.

Driving on a low or flat tire will cause irreversible damage to the rim.

Storage

Tires must be maintained during storage. Keep the tires covered and away from the elements. Do not park the tires on soft earth causing the moisture to seep into the rubber. If you park the tires on boards or pads, proper surface leveling is imperative to avoid stressing only certain portions of a tire resulting in early deterioration.

Check tire pressures monthly and keep the tire stored in maximum condition. Drive the vehicle bi-monthly to exercise the tires. Prior to taking the vehicle out of storage re-check the duals for proper spacing and to insure there are no foreign objects caught in the middle. Don't take the coach out of storage and immediately put the tires under the stress of a long grueling ride. Tires need to be eased back into operation after long periods of storage.

Your tires are exposed to more diverse applications than an automobile because they are generally out of service for longer periods of time and when the tires are in use, they carry near the maximum loads in adverse weather. Treat the tires accordingly and you will experience the long lasting life and wear modern day tires are designed to give.