Continuing plumbing water leaks

[Sully]

I have read many entries in this forum pertaining to water leaks from fittings / cone washers. But I guess I’m missing what I need to resolve this problem. We own a 2022 22MLE XLS. We’ve taking out around 8 times and just about every trip we have another water leak. (Fittings on each side of the water pump leading to water running under dining seat into the kitchen; leak on fresh water inlet behind panel in forward storage area; leak from spray valve connection in forward storage - which we’ve never used; leas from both bathroom sink valve). It appears every one is due to either the cone washers failing or hand tightened connection valves are loose. Do I need to call Grand Design to find out proper replacements for these connections. Every trip has roads along the way that has some amount of bumps. I can’t continue to chase these leaks and perform complete inspections to prevent water damage. I just cut a trip to Durango short due to leaks under the bathroom sink - I attempted to tighten and they only got worse. Are there brass connections or something better. Thanks

[Scott'n'Wendy]

I'm thinking perhaps they weren't tightened properly when built and the dealer pdi may have been lacking. Just a guess though. If it were me I'd buy a pkg of cone washers off Amazon and redo all the connections in the trailer. You would be done in less than an hour..

https://www.amazon.ca/dp/B00IRUKIO8/...lig_dp_it&th=1

Probably even cheaper in the USA

[Cate&Rob]

Sully It is unusual to have as many leaks as you describe. The cone washers typically get brittle or deformed over time or scored if the connections are disassembled and reassembled. Could you post a picture of one of the damaged cone washers? The cone washers that Scott'n'Wendy has linked, work well . . . I have used these.

If replacing the cone washer does not solve the leak, it is possible that the crimp connection between the hose and the fitting is leaking . . . this is a different problem.

Grand Design uses plastic fittings. Brass replacements are available at Home Depot or similar, but either should work. You can certainly discuss this situation with Grand Design Customer Service (contact info on our home page) and they might send you new fittings, but these will be plastic like the originals.

Rob

[Sully]

I will upload pictures of the two cone washers I removed from the bathroom sink faucet. I have new cone washers next to them for comparison. I suspect every come washer in my trailer looks like these. Are these fittings supposed to be hand tight? They also seemed a little loose, but tightening at the Rv site without new washers did not improve the leak.

Also I have a dripping leak from the right outdoor shower valve on the control panel. I have never attached the shower connection or opened that valve. It just started leaking

[Country Campers]

If you are still under warranty I would call your dealer and/or Grand Design and let them know about the outside shower valve and see if they will send you a new one. It may just have some debris in the valve that is letting it leak.

The fittings should be hand tight, but a little past that, no wrench or pliers should be needed, hard to explain the tightness needed. If they are tightened too much this is where damage to the cone washer can happen. I found a couple in our RV that would leak as you are describing and found that the new washers fixed the issue. I have also found that the whole fitting was not installed correctly.

Brian

[Sully]

Thanks for you feedback

[Sully]

I believe my warranty has expired, I replaced the cone washers on both connections under the bathroom sink and it looks like that successfully fixed THOSE leaks. I need to address every other connection in the trailer. I know the kitchen sink is behind a particle board barrier and the shower also has a small removable panel. I’m sure every fitting is suspect.

[Cate&Rob]

Sully

I wonder if the PDI done by a novice at your dealership involved over tightening all of these fittings? I can’t think of any other reason for so many cone seal leaks in one trailer. No one has (yet) reported anything like this. At least, not on this forum.

Rob

[Jlawles2]

Do you have the tankless hot water heater or a conventional one? Rob will attest and sent the links, but on both of my previous tanked campers various fittings in the camper would leak on initial hookup of the unit and if the hot water heater was drained. When I first fired up the unit, if I would "burp" the hot water about 10-15 minutes after the HWH was turned on, the problem would not happen. This is due to the expansion of the water in the system reaching pressures over 100 PSI.

First camper would leak at the toilet (cold side) second one would leak under the kitchen sink (not certain of which). Replacing the washers would cure the issue for about 6 months then it would happen again.

For the outside shower / mixing valve, you might be able to pull it apart and replace the o-rings on the stem. A trip to the hardware store (not a box store like Lowes or HD) with the stem in your hand if it's rebuildable will probably only cost you $5 in misc parts.

[Sully]

Is it possible to obtain a piping tab or layout of actual location for all of these pex valves so I can start a systematic plan for replacing the cone washers?? I was a submarine nuclear MM1 and nuc welder, I used to work in in very confining spaces. But that was many years ago when I was much more limber. I would like to know valve fitting locations. I don’t want to pay for this maintenance at the dealership- I don’t think I should have to on a new trailer even if my warranty has expired. This issue is due to poor design, parts, or over tightening by original technicians.

[ncitro]

Unfortunately not, they build them by hand on the assembly line, the location of piping, valves and connections varies from unit to unit, and can depend on who was running that station on the line that day.

[Sully]

Incredible

[Cate&Rob]

Sully

You can expect to find cone seal connections at every fixture or device. Faucets, water heater, control panel, etc. Once you replace the cone seals and hand tighten the connections, they should remain leak free for years. These connections will normally survive the pressure spikes due to water heating (that Jlawles2 Joseph describes) but if you experience an occasional leak after turning on the water heater, this is probably the reason. There are several other discussions on this forum about monitoring water pressure with a system pressure gauge and installing an accumulator tank to absorb the expansion that causes the pressure spike.

As ncitro Neil describes, towable RVs are built more like houses than vehicles. There are no drawings of how the plumbing or wiring are routed.

Rob

[acoleman43]

Sully, I had many leaks around my water pump as well. All leaks were from the fitting connections. As soon as I fixed one, another one down the line would start leaking. I'd fix that and another one would start leaking. I noticed all leaks were only at fittings with the soft water lines. all hard PEX lines were good.

I took a Saturday and re-plumbed all the soft lines with PEX lines on one side of our trailer (basically kitchen lines, water heater lines and lines to the Nautilus system). We have not had any issues since.

Now I have the black tank flush line that has been collapsed on itself. Now each time we use the black tank flush, it backs up water in our bathroom. Yes, this is a soft line as well. SO, this winter I will be dropping the bottom of the RV and replacing that line with PEX as well.

I'm not surprised you are having issues. Sorry :(

[Sully]

Grand Design should have a recall out to all owners to replace and repair these fittings. It is unacceptable to knowingly have a plumbing system wrought with leak problems and not take care of it. I was told before I purchased the trailer that Grand Design stands behind its RVs and that it was the way to go. I am truly sorry I purchased a Grand Design; I have had numerous other problems with my 22 MLE. I will never buy a Grand Design again.