|
|
RV Doctor ColumnRV Doctor #327 Dear RV Doctor, I have a 1986 Realite 27-foot motorhome with a plumbing problem that I have not been able to resolve. When using the water pump while dry camping I vent water overboard through the city water hookup until the pressure bleeds off after the pump switch has been shut off. There is a separate filler tube for the water tank. I have replaced the water pump, which worked fine, but this has not helped. I have looked for a back flow preventer in the line but can't find one. After the pump, the line is teed into a line that carries the water to the sinks and water heater in the rear. The other direction from the tee, within a foot, is another tee where water comes in from the city water hookup. That line terminates at a drain valve. All of this is located under a dinette seat and above the water tank. This problem started three years ago and has gradually worsened. Any ideas would greatly be appreciated. Don Glover, (Ft. Myers, FL)
Don, it is apparent the check valve (also known as a backflow preventer) built into the city water inlet no longer seats properly. It may be faulty to the point of replacement, or it could simply have some debris caught in the mechanism. An attempt to reseat the seal can be performed by turning on the water pump, removing the plug from the city water entry and sticking the eraser end of a pencil into the city water inlet, depressing the spring assembly. Be aware, you might get a little damp, but you also might remove the debris and allow the seat to seal by pressing in on the spring a few times. The pump pressure may be enough to force any contaminants or debris back out the inlet. If the problem persists, it will be necessary to (a): replace the entire city water entry, or (b): add another in-line backflow preventer at the outlet of the city water inlet. In other words, the new backflow preventer should be installed at some point just after the city water inlet. It's usually easiest, however, to attach it directly to the back of the inlet. All city water inlets will have a built-in check valve incorporated into its design. The water pump will also have one built in to the outlet portion of the pump. A third backflow preventer can/should be installed directly to the cold inlet on the water heater to keep the heated water from migrating back into the cold system. I've actually seen a RV that had a cold line tee'd so close to the water heater inlet (and plumbed to the toilet) that whenever the toilet was flushed, hot water (and steam) emitted from the toilet bowl. I won't comment further.
Dear Gary, I have a Sportscoach III on a P30 chassis. I need to either shorten or modify the 3-inch down tube connecting the toilet to the black water tank. The problem is that the tank is oddly shaped because part of it sits over the tag axle and is very shallow. Unfortunately that is exactly where the waste dumps from the toilet. The result is that the tube ends about 1-1/2" above the bottom of the tank (short section). Because the tank never fills to this level, even when full, the tube plugs quickly and virtually every time it is used. So, I need to either add an elbow to the down tube or cut it off flush with the tank bottom. But how do I get the tube out of the tank? Does the flange unscrew? Or is it glued directly to the tank? Mark Sherman, (Portland, OR)
Mark, indeed it is a shame when a floor plan dictates the location of such fittings with a negative result. It just so happened that the floor plan mandated the toilet be positioned over the tag axle on your rig. Most 3-inch toilet drains flow straight into the holding tank. Unfortunately, yours dumps right onto that "shelf" at the shallow end of the tank. Toilet drains may be diverted to a location further over on the top of the tank, but it requires enough clearance for three, 45-degree turns in the ABS pipe. Never use a 90-degree elbow for the toilet drain. This is possible only if you have enough vertical clearance between the bottom of the flooring and the top of the holding tank to position the three 45-degree elbows and the necessary connecting pipes. To be sure, purchase short-turn, 45-degree elbows and lay them out on the floor and measure the minimum height required. The toilet and the floor flange must be removed in order to drop the holding tank. Also, the termination assembly and the vent pipe must also be disconnected from the tank before it can be removed. Some flanges and toilet drains are glued, some are threaded and some use a simple friction seal with the downpipe inserted into a rubber grommet at the top of the tank, (see photo). The downpipe should never extend into the holding tank more than three-quarters of an inch. Extending further into the tank is only possible with the rubber grommet even though there is a lip on the inside of the grommet. Remember, it is only rubber, so a "too long" pipe can be pushed past the lip and forced further into the tank. This may be what happened on yours. If your downpipe is threaded or cemented, it cannot extend too far into the tank because the threads and the seat of the fitting would limit its travel. First remove the toilet and then the screws holding the flange to the floor. Try to "unscrew" the flange and downpipe together as one unit. (A simple removal tool can be made by using a short piece of 1 X 3 shelving material with two 3/8-inch holes drilled through it that match the spacing between the two existing closet bolts in the flange. After the toilet has been removed, place the board over the closet bolts and rotate counter-clockwise). If it will not rotate it is probably cemented. If cemented, the drain pipe will have to be cut between the bottom of the floor and the top of the tank. If you have the rubber grommet or the threaded fitting into the tank, the flange and downpipe assembly will twist free and can be removed from inside the bathroom. Careful measurements can then be made to determine if the pipe extends too far into the tank and/or if you have the needed space to install the 45-degree ells to move the inlet to a deeper section of the tank. If you have the clearance for the 45-degree fittings, then you can drop the tank, cut a new opening in the tank and have the old inlet plastic welded with a patch. Check to see if your local RV shop indeed has a plastic welding unit. Welding will be the only way to guaranty a leak-free patch. Then reinstall the tank using the 45-degree elbows; connect the termination assembly and vent. Be sure to fill the tank with fresh water all the way up and into the toilet bowl to test the integrity of the modification.
Dear RV Doc, I have a Coleman roof air conditioner on our motorhome. What wattage does it take to start and run the air conditioner? John Du Bois, (Grantsville, UT)
John, roof air conditioners must be wired to a dedicated 20-amp circuit. At 120-volts AC, 20-amps equates to 2,400 watts. The starting current needed will vary, but it could be close to 17 or 18 amps or higher depending on the condition of the compressor and where in the cycle it actually starts. Running amps should stay at about 13 - 14-amps. Obviously these are estimated figures for a properly charged unit in good operating condition.
Dear RV Doctor, I have a 1992 Jamboree that has some interior damage from water leaks. I believe I have stopped the leaking but would like to find out how to replace interior ceiling and wall panels damaged by the water. I am also looking for a replacement mattress that has a diagonal cut on the corner. Ray Pazornick, (Silver Spring, MD)
Ray, damaged interior paneling can be removed and replaced in some instances, but more often than not, it may be best to simply install new paneling over the existing panels if the structural members inside the wall are still viable. Cabinets, partition walls and other components make complete removal difficult. Oftentimes the paneling is installed before the cabinets are placed making it necessary to completely gut the interior in order to fully remove the older panels. Old paneling may be cut, with a razor knife, close to cabinetry for removal, but then it is necessary to install additional support members inside walls to attach new panels. Much easier to simply glue new panels over the old if you are sure you have the leak stopped. Unfortunately I am not aware of any instructional materials in any media available for this type of repair. The infamous corner-cut mattress. It's extremely hard to find any two RV makers using the same exact size. They all differ in some aspect; even across varying models of the same brand. There is, thankfully, a solution to this dilemma. The Perfect Fit Mattress, offered by Handcraft Mattress Company. They will custom build any style or size mattress for any RV. All they need are the dimensions for your application and this family owned and operated business will have your mattress ready in two or three weeks, typically. Call them at 800-241-7751. They will send you a brochure with all the pertinent ordering instructions. They happen to have locations on each side of the US which helps facilitate the quick turn-around time. Not only for corner-cut applications, HMC is also the source for short queens, rounded corners and any other odd-ball size you can imagine. I can still envision the weird shape of the cabover mattress in an old pickup camper I had many years ago.
|
|
|
[ Home ] [ Ask the RV Doctor ] [ RV Doctor Column ] [ Memorandums ] [ Interesting Articles ] [ Product Spotlight ] [RV Service Technician Training ] [ Seminars ] [ Links ] [ Gary's Bio ]
Send your questions and comments to:
gbunzer@cox.net |
|