Leaking Propane
I have a 1994 Fleetwood Jamboree Class C with 93,000 miles. During our last trip, we smelled propane. I mixed up some soap solution and covered all the connections. I found three leaks, so I tightened two connections and took apart the other, putting pipe dope on the fittings. But we still smelled propane. I didn’t have my tools with me, and, being a propane man, I turned off the gas, and we came home.
At home I found the leak at a flare connection. It was a double flare. I replaced the whole line up to the refrigerator but didn’t double flare the new line I put on. Does the line have to be double flared, or is this something they only do at the place they build the unit? I checked with state officials on the specific law here, and they don’t know why the line was double flared.
Kenneth Trouth, Fannington, New Mexico
BOB: First of all, you’ll need to do an analysis of the entire system. The tank leaks will have to be located by the electronic leak detector and/or soap. That’s because you can’t effectively do a pressure-drop test on the upstream side.
A pressure-drop test needs to be performed downstream of the two-stage RV regulator. This is to test for leaks, indicated by a pressure drop over time. For this test, pressure at the stove-burner orifice (using a manometer) is monitored at nominal 8-inches water column. There must not be any detectable pressure drop in a minimum of three minutes.
If the pressure-drop test shows that there’s a leak, the location of a leak can be detected using a soap (or commercial) solution or an electronic leak detector. It’s important to know that an electronic leak detector (gas sniffer) may give a positive hit on some leak-detector solutions, making you falsely believe that there’s a leak at the connection. For that reason, veteran gas people don’t use electronic leak detectors without making sure all connections are completely dry of the solution.
Double-flare connections typically are very robust and trouble free in a static environment. Therefore, you’ll need to determine why that connection is leaking. For example, a chemical corrosion problem or work hardening from line flexing or movement—possibly caused by missing pipe-support hardware—may be leading to cracks in the copper connections. The code permits single- or double-flare connections.
Since your rig is 17 years old, it’s important that the entire propane system is inspected from container to appliances. There may be other issues lurking.
Class B or Class C
A friend of mine is beginning a search for his first RV. Parking space dictates that he get a small Class C or a Class B-plus. It’s not clear what the difference is between these two designations. Could you do a short tutorial?
Tom Handy, Grass Valley, California
BOB: By pure definition, if the motorhome is built on a cutaway chassis, it’s a Class C. There are a number of smaller motorhomes built on the same cutaway chassis but without a full-size cabover. Some people call these units low-profile or Class B-plus. Typically, these units are shorter and, in some cases, not as wide as their true Class C brethren.
A Class B starts off life as a van, which is modified into a small motorhome.
Good Vibes
My husband and I own a 1998 34-foot Fleetwood Storm. We’d like to tow our 2004 Pontiac Vibe. Please recommend the best way to do this.
Sandra McWhirter, Timmons, Ontario
BOB: Your Pontiac Vibe is towable on all four wheels—without drivetrain modifications—as long as it has a manual transmission. If it has the A246E automatic transmission, it can be fitted with a Remco lube pump (LP8). You’ll have to use a tow dolly or a trailer if the Vibe has the other automatic transmission offered that year. Contact Remco at www.remcotowing.com or 800-228-2481.
Hot Fridge
We have a Dometic 3962 refrigerator installed in our 2008 motorhome’s slide-out. For the past year, we’ve struggled with unacceptable temperatures in the refrigerator section. On hot days, the box temperature hovers around 48-52 degrees, and on cool days we rarely see temperatures below 45 degrees.
We’ve had the fridge serviced many times by RV repair centers, and each time the technician tries something different to reduce the cooling temperature. They’ve installed air deflectors and even drilled a bunch of holes in the top vent cover, which isn’t very good looking.
Once we placed a small fan in the bottom back of the refrigerator, and the temperature came down to an acceptable level. I’m told this refrigerator has auxiliary cooling fans, but we never hear them. Please help.
Joe Jensen, Phoenix, Arizona
BOB: When refrigerators are installed in slide-outs, RV manufacturers must follow a whole new set of engineering guidelines. Airflow is the biggest concern, and the fact you never hear the fan is very revealing. Creating a convection pathway for the air to pass over the condenser coils is fairly commonplace for installations in a stationary wall. In these installations, the enclosure is fitted with a removable vent/door close to the floor of the refrigerator housing, and a roof vent is used on top. When the refrigerator is installed in a slide-out, only wall vents can be utilized.
To compensate for potentially lower air flow, 12-volt DC muffin fans are typically fitted in the back so that air is directed up to the top condenser coils, which can become very hot. When these coils are overheated, cooling performance is affected negatively, resulting in box temperatures in the high 40s and low 50s, which are simply disastrous levels for preserving food.
The first thing you need to check is the thermal disc that’s supposed to be attached to the outer fin on the condenser coils. In many cases, the OEM installer attaches this disc using sheet-metal screws. If the installation is not precise—i.e., screwed in at an angle—the bimetal fuse inside the disc can be damaged and remain in an open state. If that happens, the fan(s) will never come on, which I suspect is a major contributor to your problem.
You can check this by applying heat to the thermal disc with a hair dryer. If the fans (your unit should have two) never run, it’s time to replace the disc. In the meantime, you can remove the terminals from the thermal disc and connect them so the fans can be forced to run manually.
The thermostatic control of your fans may be only part of the problem. There are very specific dimensions for the compartment that houses the refrigerator. I’ve seen installations where the refrigerator is mounted too high in the box, leaving little room for air to flow around the condenser coils. I even saw one installation recently where the service guy stuffed foil insulation between the coils and the top of the enclosure. That just about eliminated any chance for the air to flow properly. Drilling holes in the top vent cover is probably an exercise in futility—and an ugly one to boot.
The two vents must be placed within the dimensional parameters prescribed by the refrigerator manufacturer. Fans typically are mounted about 45 inches above the floor and, for your refrigerator model, must provide 70 to 90 cfm each. Believe it or not, too much air can be as problematic as not enough air. The other reason for this critical dimension is to control the pattern of air that’s circulated over the coils. The air from fans placed too far from the coils will dissipate too quickly, and those too close will provide an air pattern that’s too narrow.
You can also try adding a baffle to the bottom of the top vent access cover. This should be positioned so that the air will be directed to the condenser coils. This is done when the moving air is found to exit the bottom openings of the vent cover rather than make it to the coils.
Adding another fan at the bottom of the enclosure is one way to compensate for an enclosure that doesn’t meet the refrigerator manufacturer’s engineering specifications. As you probably know, making structure corrections at this stage of the game is very difficult.
Drain Cleaner
I’ve read that one shouldn’t use commercial or household drain cleaners. What can I use to unclog my bathroom sink? It drains slowly, and I’m not agile enough to disassemble the P-trap.
Gerald Strickland, Stuart, Florida
BOB: Generally, it’s recommended not to use commercial drain cleaners because the chemicals can destroy the dump valve seals. Drain cleaners also can have a reaction to some deodorants that might be used in the holding tank.
I suggest you ask a friend to help you with the P-trap, because that’s where you’ll likely find the obstruction. You can also have the clog cleared by a technician at an RV repair shop, or do it yourself using a tool I recently discovered called a Zip-It Drain Cleaning Tool. These disposable devices do an amazing job of removing hair and other stuff from the drain, and they only cost about $4 online. Check it out at www.zipitclean.com.
Slow Shower Drain
I have a 1992 38-foot Fleetwood Bounder. The shower bathtub takes forever to drain. In fact, when I checked a few days ago, there was standing water 4 inches deep. Also, last time I camped, water seeped under the wood laminate flooring every time we showered. What could be causing this blockage?
I’ve tried plunging, drain cleaner and a commercial drain cleaner, to no avail. What do you suggest? Could the blockage be severe enough to stop water totally? Normally, hair and other debris may stop the flow, but surely water would still trickle through.
Dennis Rostant, Miami, Florida
BOB: You’ll need to get to the P-trap and clean it out. That may be difficult, depending on how the shower stall is configured, and assuming the manufacturer provided an access point. If there’s no access, you can try the Zip-It tool described in the previous letter.
In all likelihood, Dennis, your drain problem is more than an accumulation of some hair and soapy residue. My guess is that a piece of debris from manufacturing has finally found its way to a point where it’s blocking the flow. It’s not uncommon for the manufacturer to cut the hole into the holding tank and leave the round disc (or big chuck of) in the tank. Over time—and often right from the get-go—this leftover piece of holding tank lodges itself in the opening to the tank.
Trailer Odometer
I have a 19-foot tag-along trailer, and I’d like to be able to know my trip mileage. For maintenance reasons, I’ve written the start and end mileage down on paper during trips but I always wind up losing the paper! I was wondering if anyone makes a mechanical odometer for my trailer. I’ve searched diverse places without luck.
C.S. Massey, Sequim, Washington
BOB:Stemco offers a mechanical Hubodometer for trailers and probably has one that fits your tire size. It installs easily on the hub cover using one of the company’s hub mounts or universal brackets. You can go online at www.stemco.com and check the company’s application chart or call 800-527-8492 and ask someone in customer service.
Stemco hubodometers typically sell on the Internet for around $50. Expect to pay another $20 or so for mounting hardware.
Tech Topics columnist Bob Livingston has spent countless hours exploring the inner workings of RVs and finding ways to make life on the road easier for all RVers, particularly Good Sam members. Got a question about your rig? Send an e-mail to
techtopics@goodsamclub.com.