Motorhome Tire Squeal

We have a 35-foot Sunova with a Blue Ox tow bar system. The "towed" is a 2006 Jeep Liberty Sport automatic transmission, 4x4, equipped with a Brake Buddy. The system is great, easy to use and the Jeep tows great when we are on the highway. In normal turns and maneuvering it is also great. However, on some bends in the road like traffic circles, highway on/off ramps, etc., we hear what sounds like a loud tire squeal (like tires when brakes are locked). The brake system is not engaging and the steering is not locking on the towed vehicle. It has occurred both when braking and when not braking the motorhome. There are no visible signs of rubbing or tire wear and no smell of burning rubber; just the loud noise. I've talked with Blue Ox support, done Internet searches and spoke with other people who tow vehicles and no one has ever heard of this. I went over the installation with Blue Ox and it is totally within their specifications. My rear camera does not show anything out of the ordinary when this occurs, and it is very intermittent so I can't say exactly what conditions might cause it. Any suggestions how to isolate this and/or ideas of what it could be? Bob D., (Toms River, NJ)

I have to say, Bob, you've stumped me also. I've not heard of this exact problem. Do you feel any type of subtle tug; as if the Jeep brakes suddenly, but for an instant? I can only offer a couple of suggestions. First, be sure the Jeep's front end is in alignment and all tires (on both vehicles) are pressurized according to the weight they are carrying. Be sure to include any cargo you stow in the Jeep while towing. And secondly, to maybe pinpoint it better, have someone ride in the Jeep while you're towing and turning. Be sure this is permitted based on local restrictions, however. But having someone in the Jeep, even if just in a big parking lot, will quickly determine if the noise is emanating from the Jeep or from the motorhome. This is indeed a puzzler! Let me know what you find out!

Follow-up: Hi Gary! Actually, you were correct; it turned out to be the front-end alignment. I spoke with a knowledgeable service manager for the local Itasca dealer. He immediately said alignment when I described the symptoms; sent me to the tire shop he dealt with and they found the right front toe was out. Not enough to show a problem when driving or during normal cornering, but enough to make the Jeep track wide in turns when towed. This was even news to the folks at Blue Ox. Right now I can still hear a little tire squeal if I have to do a tight S-turn; sort of like bending around to the left in a traffic circle, then having to counter-steer to move right to exit the circle. I just know now to take them a little slower. The folks at Blue Ox said for that I should try to attach two bungee cords to hold the steering wheel centered. On small smart cars, the wheels run all over the place while towing straight so the bungees are needed for that. But for the Jeep, it might help it return to center quicker so it can make the counter-turn in the opposite direction.

There you go Bob! Glad it all worked out.

Ice on RV Refrigerator Fins

We are new full-timers and I’ve noticed our Norcold refrigerator fins inside the unit are icing up. What causes this or is this normal? Should I ask how to prevent this? Casey D., (St. Louis, MO)

Casey, the cause for severe icing on those fins could be a couple of things. Depending on the model Norcold, it may be a mis-positioned thermister, which is the device used to determine the cold setting on the thermostat. Or it could simply be a faulty door gasket leaking air. The first thing to do is perform, what we call, the dollar bill test. Close the lower refrigerator door(s) onto a dollar bill at various points around the entire seal, (if you have a fancy coach, use a hundred dollar bill!). With the door closed onto the bill, tug on it. You should feel a slight drag or resistance on the bill as you pull it out. If it just falls out or you feel no tug, chances are the gasket is faulty and needs replacing. Be sure to do this at multiple positions around the entire seal of each door. If that test passes with flying colors, then send me the model number and I’ll look up the exact positioning of the thermister on those fins. Also be sure you have plenty of room for air to move about inside the cabinet section. Avoid placing wide trays that may block some of the convection movement inside the box. This too, could cause some icing on those secondary evaporator fins. 

Blowout Plug Redux

In reference to your mention of using a blowout plug for winterizing I used to use compressed air for winterizing as well, but was told that this method doesn't get the water out of the check valves in the water pump and could subject the pump to rupture. I would be most interested in your comments on this. Bob K., (Murray, UT)


 Bob, keep in mind, the entire fresh water piping system is factory-tested by the coach manufacturer and tested again by the dealer at pressures around 80 PSI. So anything less than that will not create a problem within the system. In fact, in previous years the test standard was 100 PSI. The backflow preventer located at or near the water pump outlet becomes nothing more than a closed valve when air pressure is introduced through the city water inlet so there’s no danger to the pump from that side. Now it is important that the water pump indeed has a check valve located at or near the pump outlet. ShurFlo makes one line of pumps that does not come equipped with an internal check valve. In those cases, the manufacturer will install a separate check valve fitting at the pump outlet. All said, I’ve never seen a water pump damaged by injecting air into the system through the city water entry. But you make a good point about the remaining water inside the pump on the other side of the check valve! One remedy, after emptying the fresh water tank, is to remove the outlet tubing on the pump and the briefly run the pump to eject as much moisture as possible. Running dry for those few seconds will not damage the modern RV water pump. What little moisture that may remain inside the pump head will not likely cause any damage should temps dip below freezing. 

Sealing RV Clearance Lamps

I bought a 27-foot Minnie Winnie back in 1992 and have maintained it quite well. I have been able to repair all of the run/clearance light issues and I'm now ready to re-caulk them to keep the water out. I have your book and have cruised your website and the Internet but have not found specific instructions. Should I caulk all around the fixture base and then add some caulk all around the lens before putting it back on the base fixture? I recently had to take a hammer to one of my lenses that I had caulked a few years ago to get it off and it wasn't easy to find an exact replacement lens. Also, want to thank you for your You Tube video on adjusting the RV water heater flame. It helped me understand how my water heater really worked. Before I saw your video, I had replaced the electrode assembly because I thought the main burner wasn't lighting, but it was. So I cleaned the air adjustment tube, put on a new electrode assembly and still no hot water. It was driving me crazy so I reviewed more of your info and finally figured out the problem - it was one of my water heater bypass valves in the wrong position! Thanks for all the help! Cathe R., (West Springfield, MA)

Cathe, as far as clearance markers and trim lamps, always seal behind the fixture itself; between the fixture base and the side or cap on the RV. Butyl caulk is commonly used for this, but I recommend Eternabond double-stick tape. It simply is not prone to drying out and cracking over time like some butyl caulks or putty tapes. Do NOT seal the lens itself to the fixture. Many clearance lamp lenses are simply snapped into place (others are secured with screws), and all must have some method of disassembly in the likely event a bulb will eventually burn out and require replacing. Your “hammer” reference withstanding! You may even want to upgrade and switch to LED lamps.  

Great follow-through on the water heater issue! I’m happy to hear the information was helpful.

Uneven Tire Wear on Travel Trailer

I noticed that my travel trailer tires seemed to be wearing unevenly side to side. I measured to ground, the side with the most tire wear and it is about 3/4-inch lower to the ground than the other side. This is after replacing all the tires and checking inflation. I then weighed both sides of the trailer and found that the side with the most tire wear was about 500 pounds more. This is the side where the refrigerator is directly over the tires. We presently have over 15,000 miles on the trailer. Is there anything we can do to make the trailer level. I know because of the design there is little that can be done to equalize the weight side to side. Jim, (North Augusta, SC)

Jim, first of all, congratulations! You are well on your way to better balance and longer tire life simply by becoming aware of weight and balance issues. One question I have is; how was the 500 pound difference determined? The only way to determine the left – right loading is by individual wheel scales (per NTHSA). Without individual load measurements we'd only be guessing and may not pinpoint the correct fix for your issue. Weighing RV’s on a flat (platform) scale has proven to be inaccurate at best (again by NTHSA). Using individual scale readings is the only way we can determine the exact cause of your issue, since every RV is different.

I do need to ask if the heavy side is exceeding a tire rating or the axle rating? This would necessitate a more aggressive action if so.

I would look for items I could move to help the balance. Every little thing adds up and remember, just 50 pounds going to the other side equals a 100 pound difference; -50 pounds on one side and +50 pounds on the other, we are now 100 pounds closer to being balanced.

The RV Safety & Education Foundation recommends inflating trailer tires to the sidewall inflation pressure unless we have individual wheel position weights to work with. A one-inch difference in ride height on a trailer is not very much, considering the big picture, but simply adding a band-aid to make the unit level will not cure the load issue. The heavy side will still be the heavy side though it will simply appear to sit level.
 

Another cause for the difference could be what's called "spring sag." When vehicles remain loaded over a period of time, the springs will take a ‘set’ and the heavier side would be more dramatic than the lighter side. With a trailer that has had a 500 pound higher load on one side for several years and many miles, you can understand the consequences, right? This is, however, not a difficult or expensive issue to address; simply install new springs. Just be sure the shop is reputable and installs the proper rated springs.

Balancing the load and having the correct inflation pressures will have the most positive effect on tire wear, however, all the issues you bring up will contribute to uneven tire wear.