RV Doctor - Feb. 2011 Edition

By Gary Bunzer

 

George Blundon

Stettler, Alberta

 

Dear RV Doc,

 

When I am hooked up to the campground water supply, my fresh water tank fills up. How can I correct this problem? Thanks!

 

George, when the city water pressure feeds fresh water into the onboard fresh water tank it means one of two things. Either a "quick fill" valve is left open (or is faulty), or the check valve in the outlet side of the water pump has failed. If your coach is equipped with such a quick fill valve (one that allows the fresh tank to be filled while connected to city pressure), it may have failed even if it is in the "off" position. But it could also be that the backflow preventer (check valve), positioned at or near the outlet side of the water pump has failed. Though rare, this does happen from time to time. In most cases, this check valve is integral to the pump. It's not necessary to replace the complete pump; just add an aftermarket, in-line check valve to the outlet fitting of the pump and leave the defective one in the pump. If it’s stuck in the open position it will still allow water flow and the new, in-line check valve will prohibit the city water pressure from backfilling the tank.

 

 

William Jenkins

Ashville, North Carolina

 

Dear Gary,

 

I have just borrowed a 29-foot motorhome. I'm leaving shortly to go to a NASCAR® race. The air conditioner works wonderfully when using the extension cord and running off my electrical power but it doesn't work at all when the generator is on. Is there a switch I must throw to get it to convert from extension cord to generator?

 

William, typically, to get the AC power produced by an on-board generator to power the rest of the RV requires one of two methods. The first is automatic; an automatic transfer switch (usually with a time delay) senses the output of the generator and automatically energizes the panelboard distribution panel in the RV and prohibits further input from the shoreline cord. RVs must be wired so that two different sources of 120-volt AC electricity cannot feed the coach at the same time. The automatic transfer switch provides that methodology for both the hot and the neutral power conductors. The second process of getting generator power to the rest of the rig is by manually plugging the shoreline into a dedicated receptacle wired directly to the output of the generator. In other words, to get AC power to the RV you must plug the shoreline cord somewhere; either into an electrical source such as at home or in the campground, or into the generator receptacle. It’s located inside the same compartment as the shoreline cord. Pull the shoreline cord all the way out and look inside that compartment with a flashlight. I’m guessing you’ll see a 4-inch square box with a 30-amp female receptacle. Be sure all loads are turned off, then plug the shoreline cord into that receptacle and start the generator. If all the breakers are set properly, you should get power to the coach. Of course, you may have a problem with the transfer switch itself if your coach is so equipped. But that’s a whole other issue.

 

Dennis Davenport

Klamath Falls, Oregon

 

Dear RV Doctor,

I have a 2004 Host truck camper, the last of the wood frames made by Host. Last summer, I noticed what I believe you call "de-laminating" on the front of the camper. The camper's exterior fiberglass appeared to be rippling. I suspected this was related to a leak so I resealed the entire front of the camper. Recently, during a heavy rain storm, I found some water in a closet which verified there was in fact a leak and also that I didn't catch it when I resealed the camper. I have a few questions. If I can get the leak to stop will the "de-laminating" continue? Can you repair "de-laminating" without pealing back the entire exterior? If I get the leak to stop, will problems continue (dry rot etc.)? Am I in deep trouble or what?

 

Dennis, in many cases, wood frame construction is relatively easy to fix in the event that there is any damage to the structure. You are correct in that the leak source must be identified and stopped before repairing the damage. If you are having a problem finding the leak, carefully and thoroughly inspect all moldings, fixtures, window frames, and lights. Re-seal any areas that look questionable, even if you do not find any breaks or voids. Stopping the leak is the important first step, but de-lamination usually occurs only after the underlying wood and framework have become saturated with moisture. Even after stopping the leak, the wood can stay wet due to the absence of airflow and further damage could result. Some people proclaim you can inject glue behind the de-lamination and stick it back down. Typically this is a waste of time and effort, as you cannot get glue to stick to old adhesive and wet wood for very long no matter what you use. Also there is no opportunity to repair any underlying damage or even to dry the wood effectively. If de-lamination occurs and the area of the damage is small compared to the size of the sidewall, I usually recommend repairing the damage with a patch. In your case of de-lamination on the nose cap of a camper, I would recommend replacing the entire cap, as it is a relatively small area and the cost to replace vs. repair (if the damaged area is small) is insignificant, especially when you consider the integrity of the repair. Replacing the entire cap is guaranteed to be a more robust repair than a patch. A patch is also not an option if the damaged region spans a significant area. The repair process involves stripping the moldings and other fixtures, and removing the fiberglass cap from the wood frame. The insulation is removed in order to dry the wood frame and interior wall panel. This drying stage is very important for proper repair.  Any water-damaged wood framing is replaced, new insulation installed, and the nose material replaced with new, including any backing that was used on the original. In the case of a patch, it is done the same way, except only the damaged portion of the fiberglass is simply cut out. Then the framing is dried, repaired and a new section of fiberglass is inserted into the cutout and the joints finished with fiberglass cloth. This is a major repair job and I don’t recommend you attempt it yourself. Seek out an RV repair facility experienced in collision repairs. The job should not be overly cost prohibitive, as the nose on a camper is not a large area to repair, however, such things are subjective!