Why you need tire pressure monitoring

Roslyn B. says, “I have a question about trailer tires. This past weekend I had a blowout on a busy interstate. We spent two hours in 102 degrees in a precarious position waiting for the emergency assistance from Good Sam to get to us. Thankfully a FHP trooper waited with us hoping to slow the traffic speeding by on I-275.

We had the tires on my 19-foot Airstream checked out prior to our trip. The tire was only two years old. Any thoughts on what to do to prevent this from happening again? We keep it stored in an inside facility in Orlando.”

We feel you, Roslyn. A tire pressure monitoring system that allows you keep track of your tire performance might be your best option. When installed, a remote monitor in your tow vehicle tells you when a tire becomes dangerously under- or over-inflated.

Tire pressure monitors are quickly becoming a necessity rather than the newest gadget out in electronics land. Every new passenger vehicle and light truck produced or sold in America has a TPMS system for good reasons.

People are fast becoming believers, due to the fact that they’re hearing stories from other RVers or that they’ve had a near disaster or worse and experienced tire failures themselves. To most folks, TPMS systems seem complicated and difficult to understand, so we’ll try to give a “non-geek” explanation of how they work. They really aren’t that complicated or mysterious.

Tire Pressure Monitoring Sensor

First, these systems are completely wireless. This means that they have no wires running from the sensors to the monitor installed on the driver’s side dashboard area. They operate on frequencies that allow them to communicate back and forth from the sensors to the monitor. The system is constantly requesting the temperature and pressure from each sensor installed on every tire on the vehicle.

When the sensor is ‘asked’, it responds with an answer, giving the monitor the data and then displaying that information on the screen for the operator to see. Settings are established in advance so that the system understands what the high and low pressure and high temperature settings are supposed to be. As long as the tire stays within those setting parameters, the system remains quiet and displays that all is well.

If, however, the system detects tire anomalies (a fancy engineering word for ‘the system is out of established limits’), the monitor immediately goes into an alert mode, and lights and sirens go off to give the driver the opportunity to make quick educated decisions about the issue before it becomes critical.

If a nail or screw is picked up in a tire, a brake begins to drag, or a hub bearing fails, these (and other issues) can cause air pressure, the lack of pressure, or even heat to become a problem. The system immediately jumps to the problem tire or tires, and lets the driver know exactly which tire is in trouble—possibly preventing a catastrophic event.

Tire Pressure Monitoring Sensor

Sometimes the TPMS doesn’t alert the driver to a blowout in advance of it occurring, for a simple reason: if there is a catastrophic occurrence that takes place instantly—such as hitting a piece of debris or a very sharp-edged pothole—the tire fails instantly and there’s no way that the system can tell the driver ahead of time that that’s about to happen.

In any case, keep vigilant and make sure you are not driving on old tires. (The date of manufacture may be much older than the purchase date.) Make sure that you have your tires properly inflated, and weigh your trailer at a truck scale to make sure it’s not overloaded.

The TST tire pressure monitoring system is available in the Airstream Life Store.

Tire Tips—Part 2

[Want to read Part 1 of this article?  Click here]

“Ignoring your tires can result in really expensive damage,” writes Rich Luhr, publisher of Airstream Life magazine and author of Airstream Life’s (Nearly) Complete Guide to Airstream Maintenance. “When a tire blows out or is run flat, it often throws off chunks of tread which whack the Airstream and damage the body. It’s not uncommon for a on-the-road tire failure to cause $1,000-2,000 in secondary damage. So let’s get to know our tires and prevent that.”

Luhr and other experienced Airstreamers offer the following tips for buying and maintaining your trailer tires—and steps to take when they fail.

How long do tires last?

“That depends on a lot of things,” said Jon Gold, presenter of a well-received safety seminar during Alumafiesta in Tucson this year. “They last until they wear out, break, get dry rot, or you don’t like the looks of them anymore. A year, or eight years. The best way to get the longest life out of your tires is put in correct air pressure,” he said.

“The second best way is to cover the wheels on the sunny side where you park your Airstream while it’s stored. Ultraviolet radiation from the hot sun causes them to dry out and get checks,” (weather-check cracking). “If you see checks on your tires, it’s time to change them even if you have tread. If a tire doesn’t look good to you—it has a bubble, or a nail—of course, get it fixed or get a new one.”

Nitrogen. What?

Some claim that filling tires with nitrogen will improve performance and gas mileage. “Some nitrogen is good, sure,” said Gold. “But air is 78 percent nitrogen. If you’re a race car driver it might make a difference, but if you’re towing an Airstream with a maximum speed of 65 miles an hour” (the optimum speed for tire care, according to Gold), “it won’t. Just put in air. If you’re obsessive compulsive and you’re someplace that offers nitrogen, go ahead.” Prepare to lighten your wallet, though; a nitrogen fill averages $6 per tire.

Buying tires

“You can buy a brand new tire that’s one month old, or a new tire that’s six years old. The price is the same. Which would you rather have?” said Gold. The answer seems obvious, and there’s a way to find out when a new tire was manufactured. Look at the four-digit code in the oval on any American-made tire—the last two numbers are the year it was manufactured; the first two numbers are the week of the year it was made. (Examples: 0111 means that tire was made during the first week of 2011. 5213? The 52nd week of 2013. You got it.)

“You can say, ‘I want a tire that’s less than six months old, and I’m going to check’,” said Gold. Make sure new tires in the shop were stored properly—on their sides, not on the treads.

Goodyear vs. Michelin

Your Airstream comes from Jackson Center with Goodyear Marathon trailer tires. “I’m not a fan,” said John Irwin, long-time Airstream owner and frequent contributor to Airstream Life magazine. “I’ve had multiple problems and blowouts over the years. I went from those to E-rated truck tires and they were worse! They failed just as often, and when they did they tore up the trailer. They shed tread but retain air, so the tire monitor doesn’t always go off when they fail and they can be back there beating the heck out of the side of the trailer.”

Irwin now uses Michelin light truck tires on 16-inch wheels. “I’m convinced those will take care of me,” he said. “They’re worth the cost—$1400, whatever—particularly for long distance travel.” Airstream began installing Michelins on the Eddie Bauer, and made the upgrade available for other models when customers clamored for better tires.

Blowout!

Airstream tire blowout“Blowouts are rare, but if you do happen to get a flat tire, blowout, or loss of air, do NOT jam on the brake,” said Gold. “Hit the gas pedal, regain control of vehicle, then take your foot off the gas and look for a safe place to stop.”

“If you brake, you put more weight on the flat and it will yank you in that direction,” he explained. “It’s counterintuitive, but instead grab the steering wheel, hit the gas pedal real quick to lighten the weight on the front, then back off. If you see or hear or feel a tire going flat, maintain control, and gradually pull over. Don’t just yank over to the side, cutting people off.”

What about a slow leak?

“If I’m on the highway and know I’m losing air, I’d rather go to a good tire shop, even if I have to go thirty miles to find one,” said Irwin. “I carry a bottle of Fix-A-Flat and put some of that in there and keep going.” Look at the labels on tire sealants. “Some have a warning that they’re dangerous for anybody who has to work on that tire later,” said Irwin. “Choose one that’s safe. It will usually cost a couple dollars more.”

Be prepared with the items you’ll need to fix a flat:

  • Breaker bar with extension and socket
  • Leveling blocks
  • Visibility: fluorescent vest, flares, flashers or cones
  • Tire pressure gauge
  • Torque wrench
  • Torque stick (only if you might let a shop put the wheels back on for you)
  • Mechanic’s gloves (optional, to keeps your hands clean)

How to change a tire

Changing Airstream tire“Everyone calls it ‘changing a tire’ but what you are really doing is changing a tire and wheel assembly. The wheel is the metal part, the tire is the rubber part, and you are going to remove them as one piece,” explained Luhr. “Later, a tire shop will remove the tire from the wheel to patch or replace it.” If you get a flat, stay calm and follow his step-by-step instructions:

1.Airstreams don’t come with the tools you need to change a tire, so it’s up to you to obtain the necessary tools and carry them in the Airstream. The lug nuts on most Airstreams require a 13/16” socket, but some may need a 3/4” socket. You’ll also need a 1/2” drive wrench (also called a “breaker bar”) and a 6” or longer extension, or a cross-type lug nut tool. To put the lug nuts back on correctly, you should have a good quality torque wrench, also in the 1/2” drive size.

2. If you are working by the side of the road, it’s a good idea to put out some flares, orange cones, or whatever you might have to warn people zooming by. At the very least turn on the hazard lights on the tow vehicle—they’ll flash the Airstream’s taillights too. Make sure you’re visible as well, by throwing on a reflective safety vest or shirt.

3. Get the spare tire and wheel out of its carrier. Check the air pressure in the spare. If it’s low, you should add air to get it up to the recommended pressure. A tire that is low on air is likely to blow out, which could make things a lot worse. If the pressure in the spare is more than 15% low and you can’t add air, you might consider three-wheel towing for a short time.

4. Next, loosen but do not remove the lug nuts of the wheel you need to remove. This is because it will be difficult to loosen those nuts once the wheel is off the ground. If you can’t get the nuts off with your arms, try positioning the wrench so you can put your foot on it.

5. Once the tire is back on the ground, you must finish tightening the lug nuts to the factory spec. The correct torque is extremely important. Under the right amount of tension, the wheel is drawn to the brake hub face and the lug bolt will be well mated with the lug nut. Too much torque and the lug bolt will be stretched, and eventually break. Too little tension and the lug nut can work off.

6. You can’t judge the correct tightness accurately by feel, so you need to carry a torque wrench, and instructions on how to use your torque wrench should come with it. For most torque wrenches you set the target torque in foot-pounds and the wrench will “click” when you’ve tightened the nut to that setting. Remember to re-set your torque wrench to zero when you are done with it.

7. Check the Owner’s Manual or documentation for the wheels to verify the correct torque, and make a note somewhere of that number so you have it handy when you have to replace a wheel.

8. Don’t let tire shop personnel put your wheels on with an air wrench. Air wrenches can put out far too much torque and overstress the lug bolts. Instead, insist they use a manual (hand) wrench, or get a “torque stick” rated for 60 ft-lbs and have them use that. Then tighten the nuts to the correct torque specification with your torque wrench. Better yet, just tell the tire shop to give you the wheels when they are done, and you can put them on yourself. That way you know it will be done right. Use the torque wrench only to tighten the lug nuts, never to remove them. It’s a calibrated instrument that can go out of whack if you use it to remove nuts.

9. It’s very important to re-check the lug nuts after the trailer has been towed for a while. This is because the lug nuts need a little time to “seat” properly. A common recommendation is to check the lug nuts with your torque wrench after 25 miles, then again at 50 miles, and one last time after 100 miles from when you changed the tire. If you don’t check and re-tighten the lug nuts to proper torque, they may loosen over time, which can lead to losing a wheel.

If you missed Tire Tips — Part One, find the complete article here.