Blowout
I am writing to ask your advice about an accident I had June 7, 2009. I purchased my first motorhome, a 2004 40-foot Holiday Rambler Imperial, in April 2009 and used it on a couple of trips for about 3,000 miles. At the time of the accident, it had approximately 56,000 miles on it.
The Friday afternoon before the accident, I visually checked all the tires and used a digital pressure gauge to confirm all of the tire pressures. All were within the recommended pressures and showed no damage or scuffing.
I was driving on Interstate 65 at about 70 mph. The motorhome was operating normally, with no pulling or vibration. As I merged into the right lane after passing a slower truck (the motorhome was on cruise control), the front right tire blew out. The RV dropped down on the right front and pulled right at about a 30- to 40-degree angle even as I turned the wheel to the left. I left the interstate and went into a ditch, fortunate that I was able to avoid hitting anything or turning over.
The motorhome was equipped with Goodyear 296/80R22.5 tires. The tires appeared to be in good condition with good tread life as far as I could tell. In more than 2 million miles of driving cars and SUVs, I have never had such a catastrophic tire failure or direction control problems as I had with this motorhome. I am very concerned about this.
The tire exploded in the center of the tread with a shotgun-like blast, not a fast or slow deflation. The obvious answer is that anything could have happened to the tire prior to my purchase. If that were the case, how could the type of damage capable of causing this type of failure not show signs or warnings? Is the strong pull following the blowout typical of a Type A motorhome? What could I have done to prevent this? What kind of inspection would indicate this type of problem? Should the steering allow this overpowering pull?
I know the tires have not struck anything since I’ve had the motorhome, but I don’t know about before then. Are there any problems with Goodyear tires?
Walter Drey, F407374
Theodore, Alabama
I’m very sorry to hear about your accident, and I’m very thankful that you’re okay.
Let me say that a tire blowout such as the one you described is not a normal occurrence, but it does happen. I’m sure you’ve seen blown-off tire carcasses along the highways that were lost from long-haul trucks.
Also, there’s nothing inherently wrong with Goodyear tires. I did not find any recalls on the tires you mentioned and I’ve not heard of any specific problems with those tires.
As you said, you don’t know what was done to the tires before you purchased the coach. Tire engineers have told me that tires have a long “memory.” Your tire could have been damaged at an earlier date, and then suffered the failure when it struck something at that precise spot (it could have even been an expansion joint in the concrete). This is why everyone in the coach should always wear their seal belt when traveling.
Two other factors that could result in a blowout, besides tire damage and road hazards, are an overweight condition or the age of the tires.
I would suggest that you read my “Weight and Tire Safety” article published in the July 2007 issue of Family Motor Coaching and available online in the back issues section of FMCA.com. Granted, your motorhome is only five years old, but the tires with which it is equipped could potentially be older than that. As a rule of thumb, the average life span of an RV tire is 6 years. Tires that are more than five years old or ones that show signs of cracking should be inspected regularly by a tire professional to determine whether they should remain in service. Factors such as load, the tire’s inflation, sun damage, ozone pollutants, driving speeds, and frequency of use are just a few of the causes that age a tire. In most cases, motorhome tires need to be replaced because of age rather than wear. The July 2007 article I referenced discusses how to read the DOT imprint on the tire sidewalls to determine the age.
Another good source of information is the RV Safety & Education Foundation (www.rvsafety.com). The company presents a tire and weight safety seminar at FMCA conventions and some area rallies. Their Safety Education Package incorporates an excellent video that was produced by Michelin Tire Company on the subject of safely bringing a motorhome to a stop in the event of a tire blowout. Even though one’s first instincts might be to hit the brakes (I’m guessing that since you were using the cruise control that you immediately hit the brakes to disengage the accelerator), Michelin recommends briefly pressing the accelerator to the floor (if traffic conditions allow) to regain momentum in the direction you are going and then gently taking your foot off the accelerator. Hold the steering wheel firmly and regain control. If you are on an expressway, gradually move into the far right lane. Immediately turn on your emergency flashers to let traffic around you know that something is amiss. Slow your coach down, without applying the brakes, to 10 to 15 mph before pulling off the road surface.
Although the extreme pull you felt is relatively normal during a steering tire blowout at high speed, there are some products designed to help reduce the sudden shock to the steering that you felt. Two such products are the Safe-T-Plus from United Safety Apparatus (www.safe-t-plus.com; 800-872-7233) and the Steer Safe (www.steersafe.com; 800-845-5504).
Response To “Wet Walls”
The wet wall syndrome that Mr. Hill described in his Tech Talk letter (“Wet Walls,” November 2008, page 20) is very common. I, and all of my friends who are full-timers, have experienced this at some time. It is so common that it is pointed out in my coach’s owners manual as a possible problem of which to be aware.
I disagree with the response given by the editors. First, using fans to circulate the air will re-evaporate the moisture back into the living area (not good), which I would not recommend. You would be better wiping up the moisture and disposing of it. Second, RV furnaces DO NOT use interior air for combustion. The furnace burners are located outside of the living space and use outdoor air for combustion. The furnace then uses a heat exchanger to heat the interior air while the air used for combustion (now loaded with carbon monoxide) is vented back outside the RV. A wet bulb thermometer can be used to measure the dew point temperature of the air, not a hygrometer (I doubt seriously any service center will have one), but the reality is he just has too much humidity in the coach.
Mr. Hill’s coach could have an issue, but it is probably just high relative humidity caused by their type of living. Showering requires using the exhaust vent and drying out the shower afterward. Cooking also can produce large amounts of water vapor in the air, especially when making pasta or using a pressure cooker. Don’t forget that humans emit a substantial amount of water vapor, especially when moving about. If the coach is closed up tight, the water vapor has nowhere to go.
When we owned a land home, we had ceilings that included R-30 insulation or better, and walls with R-16 insulation. The ceilings and walls in a coach are 2 inches thick or so. I’m not sure what the R value might be, but these surfaces will lose their heat to the outdoors very quickly and reach the dew point temperature of the inside air, allowing surfaces to sweat if the occupied space has high humidity.
I found after purchasing a hygrometer that the relative humidity in my coach was well above 60 percent most of the time and sometimes as high as 90 percent. Any surfaces that are at the dew temperature at night would sweat profusely, and twice I had “water running down the walls.” As I am writing this response, there is some minor sweating on the windshield and other metal surfaces in my motorhome, even though the relative humidity is 41 percent, but it is 30 degrees Fahrenheit outside. As we have spent two winters where it gets below freezing at night, I establish the relative humidity at 40 percent using a dehumidifier. I purchased a floor model with decent capacity (for the area of the coach) and mounted it permanently. It runs on and off all winter.
I hope this explanation helps, as this problem does need to be controlled. The last thing you want is black mold growing because of the moisture, and it will start at 60 percent humidity or so.
Dennis McCanna, F392956
Rapid City, South Dakota
Thank you for sharing your thoughts.
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