A Pressurized Situation
Dear RV Doctor:
In the “Tech Talk” column that appeared in the June 2013 issue of Family Motor Coaching, the answer to the “‘New’ Motorhome Problems” letter (page 21) offered information about pressure testing the fresh water system for leaks. It said that the factories use 80 psi to test fresh water systems in new motorhomes. If the water systems can take that kind of pressure, why are pressure regulators sold on the market set at approximately 50 psi? I would love to have more pressure in my system, but I have been afraid to up the pressure. Now I find out that the manufacturers test it at 80 psi. To what pressure can I safely increase my incoming water?
Deane Rhoadarmer, F388459
Porterville, California
It is true that RV manufacturers test the fresh water system at 80 psi, typically using air pressure. It’s a code-required test. But as you use your motorhome, you are limited by the amount of pressure coming out of the spigot at each campsite. It’s not really an option to “up the pressure” as provided by city water connections. You’re also correct in stating that the common, nonadjustable in-line pressure regulators reduce the incoming water pressure to approximately 45 to 50 psi. Likewise, when operating on pump pressure, most pumps today have a nonadjustable pressure switch integral to the pump. Some water pumps, however, are rated at a higher output pressure and a higher water flow measured at cubic feet per minute (CFM) than other pumps. When it comes time to replace your current water pump, look for one with the highest output pressure and CFM. But at the campsite, you’re limited to the amount of pressure provided by that municipality, which usually averages between 60 to 80 psi. Still, you must be cognizant of unregulated park systems and other hookups that may have extremely high water pressure, so my advice would be to purchase an “adjustable” in-line pressure regulator and keep it below 70 psi. That way, you can maximize hookups with average pressure and limit those with extremely high pressure. But I wouldn’t push my luck setting the pressure to the test pressure used by the manufacturer.
A Filtering Moment
Dear RV Doctor:
We have a 1986 Allegro Type A motorhome. We are trying to remove a broken oil filter from the generator. Do you have any suggestions on how to do this?
Gary Childs
Without seeing the broken filter, it’s tough for me to provide a good suggestion. (How does an oil filter get broken anyway?) Also, you don’t mention which brand and model of generator you have. In some cases, a specialty tool might be able to reach in and grab whatever portion of the filter is left. Perhaps a large basin wrench or, one of my favorites, a strap wrench would work. In other cases, it may be necessary to remove some of the metal shielding to gain access. Further, you may need to remove the generator and disassemble some of the pieces in order to get the right tool on the remaining portion of the filter. If you feel it is beyond your scope, a certified RV service technician likely will be able to determine the most appropriate approach, since the tech will have some product knowledge. Personally, I’ve never run across this issue with an RV generator. I certainly wish you luck.
A Forgotten Surface
Dear RV Doctor:
We have a 38-foot 1998 Holiday Rambler diesel pusher. We use the motorhome a lot in the winter on weekend ski trips and as a mobile hotel room when we visit our son and daughter. The one issue I have had with the motorhome is the amount of corrosion that’s appeared, especially in the rear section. The framing in the basement compartments has rotted out. The (coolant) plumbing in the engine compartment also has rotted out, along with the hydraulic hose fittings. I finally replaced the basement container boxes with much heavier diamond-plate aluminum sheets, and I had the whole underside and all of the framework blasted, painted, and sealed with a thick undercoating.
Are any of the manufacturers in tune with corrosion issues and rust-proofing protection? Is undercarriage corrosion a general problem with motorhomes? I believe most buyers don’t look underneath their motorhomes at the steel structures. I don’t want to go through this again with a new coach.
Zack Bowen, F393203
West Chester, Pennsylvania
The undercarriage is what I refer to in my seminars as the “forgotten” exterior surface. Manufacturers are seemingly so focused on the aesthetics of the visual interiors and exteriors that some simply may not put enough emphasis on the undercarriage. And owners rarely focus on cleaning the underside of the motorhome to remove the corrosive materials that are picked up while traveling. The big issue in your location is the slush and salt mixture your coach is exposed to each winter. Likewise, RVers living near the coastlines probably suffer similar deterioration on their units.
Some manufacturers do a better job of sealing and protecting the undercarriage than others, but it all depends on the factory doing the work. I know of no specific manufacturer that pinpoints their undercarriage protection as a selling point, although manufacturers who specialize in building “winter use” coaches, with thicker insulation and double-pane windows, for example, certainly know of the ramifications of traveling in snow and moisture during winter. I would imagine that their undercarriages are better protected than the average motorhome. I’m unaware of any specific issues with the undercarriages used on older Monaco products.
I believe your problems are probably related to the extremes the motorhome has been put through since it was built. There are certainly undercoatings, sealants, and protective applications available, and it’s simply up to the manufacturer to decide the level or degree of protection they’re willing to include in a particular product line. I’ve seen everything from nonpainted, raw wood structures under some RVs all the way up to fully sealed, insulated, and undercoated undercarriages. It’s likely a decision the manufacturer makes based on the economics of that product line.
Dealers could better serve their customers by inquiring how they intend to use the motorhome and then suggesting aftermarket services to alleviate certain problems from happening. An astute dealer would have asked whether you planned to travel in the winter, or to stay for extended periods near the shore. Salt air simply wreaks havoc on metal surfaces if not prepped properly. Aftermarket services for undercoating abound on the Internet, but it is important that the process involve a high-pressure cleaning of the undercarriage first, then an application of a rust converter prior to applying the actual undercoating. If a rust converter is not used, rust and deterioration will simply reappear and the effort will be for naught. Also, when you decide to trade up, include a proper undercoating process as part of the deal on your new motorhome.