Anyone for Air?

I’ve been looking into air ride hitches. I have GMC dually and a 30-foot 5th wheel travel trailer. I am looking for a safer, smoother ride while towing. Some of the road surfaces jerk the trailer so much it seems like something will break. I’ve seen variations from $1000-$2200. Do they really work? Is it worth the money?
Joe, (Endicott, NY)

Though I do not have direct experience towing a fifth-wheel, Joe, I have studied many of the accessories and add-ons available. I have looked closely at the Trailair Air Ride pin box and am impressed with its design. I have spoken at length with the president of the company and feel this is one that may actually work quite well. It certainly warrants a closer look. But only you can make the subjective decision as to whether it will be cost effective though. Check them out at: www.trailair.com.

Gen Hours

We are interested in buying a used RV. They often tell us how many hours are on the generator. What is the life of a generator? What would be considered low hours vs. high hours? This info would be so helpful to know if what we are looking at is "very used" or a good sale.
Janet, (Worcester, MA)

Janet, RV-approved generators are sturdy units, but extended use without proper maintenance can take its toll over time. This toll is somewhat predictable, however, and manufacturers usually specify maintenance and inspection intervals based on the number of operational running hours such as every 50, 100, 200 and 500 hours. It's impossible to determine just how many hours per year would be an average. And keep in mind, a well maintained generator will last indefinitely. 

With all the amenities found in the typical campground today it would probably be rare for the casual RVer to rack up more than 150 hours or so per year. Unless of course, they spend a lot of time off the beaten path or at tailgate parties, (many do both).

A generator load bank test can be performed to determine how well it responds to varying loads. This will provide some indication to its general state of well-being. Many proactive RV shops will offer this service. If you have a serious concern about too many hours based on the year of manufacture, the only true way to determine how hard the generator has been operated is to remove and inspect the cylinder heads. A close internal inspection of the heads will reveal to what extent the unit has been pushed (see photo). Carbon buildup and cylinder wall scoring, etc., all provide clues. But even if it has a ton of hours and the owner can verify that the manufacturer-recommended maintenance interval checks were performed, I wouldn't be overly concerned. It wouldn't be a deal breaker, but perhaps a negotiating chip!

Tire Damage

I am interested in receiving some information about the negative effects of ultraviolet rays causing damage to the tires on my fifth wheel trailer. Why are RV tires so susceptible to damage from the sun when the tires on my truck don’t seem to be affected? What are the facts?
Murray (Alberta, Calgary)

Murray, the damage caused by ultraviolet (UV) radiation as well as exposure to the ozone virtually effects all tires. RV tires in general are more susceptible to this type of damage since they are considered a slow wearing tire. RV tires typically are not driven as far or as often as regular automobile tires. 

A symptom of ozone or UV damage is the evidence of cracking or “weather-checking” around the sidewall. Ozone is simply a gas that is in the atmosphere. A mutant of sorts, ozone consists of an extra oxygen molecule which is easily attracted to the oxygen in the air and just as easily attaches itself to other oxygen-related compounds such as water and carbon monoxide. The biggest detriment is that it virtually attacks the rubber in the tires and causes brittleness and a lack of pliability. The big disadvantage – ozone-produced cracks cannot be repaired or restored. The tire must be replaced. 

One of the ways tire manufacturers combat ozone is by blending ozone resistant rubber compounds during the making of the tire. These special waxes form a protective barrier against the ozone, but in order to be effective, the waxes must be constantly brought to the surface of the tire. During the flexing and moving of a tire while driving, a fresh layer of combative waxes is kept at the surface. Dormant tires on stored vehicles do not receive enough “exercise” to allow the waxes to migrate to the surface and the ozone has a virtual picnic on any exposed area.

Ultraviolet light (UV), on the other hand, is produced by the sun and travels in the air as solar radiation. An invisible light, UV is harmful to all rubber, plastics, fiberglass, etc., all of which are common to RVs. The effect of unprotected UV exposure on rubber is similar to that of ozone damage – cracking, discoloration and lack of physical mechanical properties. Like the ozone war, tire makers use a carbon substance to combat the effects of UV radiation. Carbon black is an UV stabilizer that actually absorbs the damaging rays and converts them to a simple heat by-product. The carbon substance will eventually lose its ability to protect against the never-ending assault of the UV rays. Contrary to what some suppliers may say, there is no such thing as a permanent UV protector. Here are a few ideas suggested by virtually every tire manufacturer;

1. Keep RV tires clean. Avoid heavy buildups of mud, sand or dirt. Dirt on tires may act as an abrasive of sorts that could inhibit the natural wax protection achieved through normal tire flexing. Also, regular washings with mild, soapy water and a soft brush can remove significant amounts of ozone, especially if you are located in a higher-than-normal ozone area.

2. Inspect the tires regularly.

3. Inflate the tires to the exact requirement based on the actual weight at that tire position.

4. During short periods of non-use, keep the tires completely covered. When possible, remove and store the tires completely out of the sun and temperature extremes.

5. Regularly apply a non-petroleum-based preservative to all surface areas of each tire.

By following these simple guidelines, most RV tires will provide many miles of safe travel.

Vapor Lock

I bought a used Dodge-powered RV with 27,000 miles. My son and I have been repairing things that have happened to it over the years. It was used in California for awhile, then to Phoenix for years and sat out in the sun. The engine appears fine but on a trial run a transmission seal gave out. We had it repaired and the tranny rebuilt. Recently we were going to a racing meet where the temperature was ninety-three degrees. Eight miles down the interstate the engine started cutting out, but we finally limped home. A serviceman said it was undoubtedly the fuel pump vaporlocking and that it was normal for RVs in hot weather. He said to put an electric fuel pump in it. Is this problem solved by installing an electric fuel pump? Another fellow also told us that lousy gas diluted with alcohol also causes vapor lock. He said to add five gallons of diesel fuel to our forty gallons of gas. He said it will smoke a little, but will get you out of troubles. I also have a kit of a woven insulating material to cover the metal line from the fuel pump to the carburetor to insulate against the heat. We are also putting in a new fuel pump, since it has been setting dry for a long period. I also thought about installing a windshield washer which sprays the front of the radiator to help cool it. We just don't want to get trapped on the interstate this summer if we can help it, so will appreciate any tips!
Dr. Ron, (Niwot, CO)

Dr. Ron, indeed adding an electric, pusher-type auxiliary pump will help rectify vapor lock problems on most older Dodge chassis motorhomes. Installing the pump as close to the tank as possible usually provides the optimum performance. 

Insulating the fuel line, as you suggest, is also a worthy practice, but consider instead going to a larger size fuel line the entire length of the run. Some OEM applications found the original 5/16" fuel tubes mounted inside the frame rails close to exhaust components which simply amplified the problem. Installing 3/8" fuel lines and mounting them on the outside of the frame rails will help tremendously.

It is also advised to replace all rubber hose sections found in the fuel line including the hoses at the tank takeoff tube and all vapor return lines. Since the RV sat for so long and you have already experienced rubber seal deterioration, it's a sure bet all rubber products have deteriorated to some degree. 

Aside from vapor lock, you may be suffering from fuel starvation; literally sucking air through cracks in the rubber sections. Look closely, there are quite a few rubber sections in the system. Normally I shy away from backyard mechanic tricks like adding diesel fuel to the gasoline. Aftermarket products exist that would be a much better choice. And unless you are experiencing extreme overheating there is no viable benefit to spraying water onto the radiator.

No Main Burner in Oven

I have a motorhome with an older Magic Chef LP range. The oven pilot lights and stays on and gets brighter and higher when you turn up the thermostat, but the burner in the oven never lights. I have checked everything I can think of. I would appreciate any troubleshooting tips you might have.
Gerry (Bryan, TX)

Gerry, assuming the LP pressure is set correctly at 11.0 inches of water column and the unit is relatively clean, here’s what should happen. When you set the oven thermostat to a desired cooking temperature, the standing pilot flame becomes slightly larger, which you have noticed, and begins to heat a thermal bulb attached to a component called the safety valve. This thermal bulb, which is filled with mercury on the older units, expands a bellows in the safety valve and allows the main burner gas to flow from the thermostat to the safety valve and then on to the main burner. As the secondary flame becomes larger, be sure it fully engulfs the thermal bulb. The positioning of the thermal bulb in the secondary pilot flame is crucial. It has to be directly in the fire in order to boil the mercury inside. If it is indeed fully engulfed, the safety valve is probably faulty and needs replacing. Safety valve replacement requires removing the range to gain access to it. And since it can sometimes be a tricky replacement, this one might be best left to the professional technician.

Level for Refrigeration's Sake

I have a Class A motorhome and I often find it challenging to level my rig in some campsites. Is it really that important that the unit is level? I know it was important for the older refrigerators, but with the new ones is it still critical? Also, if it does cause damage running off-level, is it less critical if I am running the refrigerator on electric as opposed to gas?
James (Watsonville, CA)

James, keep in mind that the force which moves the liquid contents throughout the refrigerator cooling unit is nothing more than gravity. From the point where liquid is first produced in the condenser section until the liquid reaches the boiler section, gravity is employed. Since liquids cannot flow uphill, the importance of running the refrigerator only while level is fully appreciated. 

The crucial section is the low temperature evaporator located within the freezer compartment. To the refrigerator, it matters not how level the galley countertop is, or the dinette table, or the outside corners of the RV. If it does not correspond with the low temperature evaporator coils located in the freezer compartment, all leveling efforts will be for naught. With repeated operation out of level, damage to the cooling unit is inevitable. Leveling is important during any operational mode (12-volts DC, 120-volts AC, or LP) while the RV is parked. While driving or physically moving down the road, there is enough jostling and movement to keep the liquids safely flowing through the system. It is only crucial when the vehicle is not in motion. 

True, today's absorption refrigerators are more forgiving than earlier predecessors, still all RVers should make every effort to completely level the refrigerator. To risk any operation out of level could be an expensive wager indeed. See the photo above for a bunch of reasons to take the time to level the refrigerator properly.