Pex Plumbing

[Guest]

If a hose begins to leak just from touching it, there remains the likelihood it will eventually fail whether touched or not.

Jim

[Jlawles2]

If touching it will make it leak, what about rolling down the road. Remember a travel trailer is a rolling 3-4 earthquake (minimum possibly worse).

[Cate&Rob]

I found the main issue with the soft hose and fittings is when you touch the soft hose. If left alone and not moved, they seem to preform adequately. If you have to move the hose around (or if it moves a lot while traveling - or have to replace a water pump...sigh) you will get a leak at the fitting. So you replace one fitting...but in the process moved the soft hose and the fitting at the other end starts to leak. This continues until you end up replacing everything with true pex pipe and brass fittings.

I would agree with AC’s summary of the situation. This is exactly how my journey to first repair and then replace all the soft hose, started. I disconnected and reconnected the original soft hose to the toilet . . . then discovered a new drip leak where the other end of that soft hose was crimped to a Pex fitting below the floor . . . and so on . . . and so on . . .

Rob

[SATA Adventures]

I was in the belly of my coach after reviewing howson 's review of replacing all the pex lines back in 2020. I found that my soft lines are stamped with 80 PSI ASTMF2159 2098/ ANSI-SAE J1670. Some have stated they have 150 PSI lines which I am not arguing with just making sure people know that there are other lines going out there with the 80PSI.

Hearing that the experience is that once you touch them they have more potential to rupture or leak I am going to hold off trying to insulate my hot water lines until I can plan on replacing all the soft lines first. Don't want to have to do it 2x.

[Guest]

I was in the belly of my coach after reviewing howson 's review of replacing all the pex lines back in 2020. I found that my soft lines are stamped with 80 PSI ASTMF2159 2098/ ANSI-SAE J1670. Some have stated they have 150 PSI lines which I am not arguing with just making sure people know that there are other lines going out there with the 80PSI.

Hearing that the experience is that once you touch them they have more potential to rupture or leak I am going to hold off trying to insulate my hot water lines until I can plan on replacing all the soft lines first. Don't want to have to do it 2x.

This is really odd. Wonder how I ended up with 150psi hose in my 2017 Imagine or why they went with 80psi hose???? The hose must match or exceed the T&P or its a failure waiting to happen. I do not have a pic of the red hose but its 150psi rated as well.

Jim

[TedS]

The hose in my trailer is rated for 80psi.

[carrtommy]

I have a 2022 Grand design Imagine 22MLE. The second time I used the trailer which was this past weekend (10/28/2022), the soft flex hose under the bathroom sink began to leak. I had to replace the pex clamps with something better suited for soft tubing which is stainless steel hose clamps that are tightened by tightening the clamp screw. Grand Design should not be using pex tubing clamps on soft tubing. I had to replace all 4 pex clamps under the sink that were used on soft tubing. The pex clamps I did not replace were used on pex tubing and are designed for that.

[Guest]

I have a 2022 Grand design Imagine 22MLE. The second time I used the trailer which was this past weekend (10/28/2022), the soft flex hose under the bathroom sink began to leak. I had to replace the pex clamps with something better suited for soft tubing which is stainless steel hose clamps that are tightened by tightening the clamp screw. Grand Design should not be using pex tubing clamps on soft tubing. I had to replace all 4 pex clamps under the sink that were used on soft tubing. The pex clamps I did not replace were used on pex tubing and are designed for that.

Excellent!!!

The pre-determined clamping force on a PEX clamp is made for the wall thickness and rigidity of PEX tubing on a PEX fitting and nothing else.

Jim

[TheNescios]

Getting ready for a trip in a few weeks and doesn't look like I'm going to get all the flex hose replaced.... but will have a decent selection of Pex fittings and hose clamps with me to complete the task when I reach my (hopefully) warmer & nicer weather winter location - or have to make an "on the go" repair during the trip. It's mind-boggling to me that with how well documented the issue is with Pex to flex hose issues are the industry continues doing this? Went to an RV show not long ago and noticed it seems to be a common practice across many different brands.
Brings to mind the "definition of insanity" phrase?

[Cate&Rob]

TheNescios
Hi Chris,

I recognize that famous “definition of insanity” quote and this is a true application of that observation!

Use of soft hose is all about expediting assembly time. If you have ever been in a towable RV manufacturing facility running at full speed, it is a frantic place, using manual labour assembly processes abandoned by other North American manufacturing industries over 50 years ago. As long as the RV industry remains centred in Indiana, nothing is going to change this.

Rob

[Lptxtandem]

For those of y'all that replaced the polyvinyl hose, did you have to drop the underbelly? Also did you use the copper rings or the stainless clamp?

Also, hav any y'all used these...

[StephenO]

Greetings Lptxtandem

While I cannot directly speak to replacement of the soft hose with PEX directly as I have not (yet) needed to do that 'upgrade', but I would assume that it would be much easier dropping the underbelly cover. I would guess it would be difficult to fish PEX piping through the underbelly area, but I am sure someone with firsthand experience will come along shortly and confirm this.

In terms of the PolyB to PEX fitting you asked about, those have been discussed before. More specifically, check out this post where Country Campers discussed using them without success.
https://gdrvowners.com/forum/operati...5511#post75511

Welcome to the forum, and be sure to checkout the Welcome Letter to help you get setup

https://gdrvowners.com/forum/main-fo...to-new-members

[TheNescios]

Been offline while in Mexico so a bit of a delayed response but my preference after researching and reading posts on this forum is the SS clamp and the crimping tool with the light that tells you when it's fully crimped which works well but is a bit bulky.
Keep in mind it can be a #$@@$% in tight quarters to get lined up correctly and may require more than 1 attempt to get them done correctly - patience is a virtue and it would also help if I was 10 years younger and a few pounds lighter.
As for the underbelly, on my unit so far it's looking like PEX was run in most areas and it's the under sink, toilet, and such connections when the runs come back into the living area where they used the flex hose. And also quite a bit of flex around the backside of the Nautilus and water heater - getting the plastic 90 degree bend whatchyamacallits is good - cuts down on the number of fittings which in my mind cuts down on the friction loss points that reduce flow & pressure. They don't make a true 90 so it's helpful to keep a scrap piece of PEX in one of them to help figure out placement and length of PEX to cut.

Hopefully this helps?
It's not exactly a fun journey or task, but at least you'll know it's been done with some care and attention to detail!

[Jlawles2]

If I ever redo the plumbing I want to go PEX-A with the expanding collars. Those seem to be a bit more forgiving for placement as you only need to get the expander tool in the end, but since the line flexes, much easier to accomplish. Plus the fittings are "full bore" vs the others that are reduced ID.

[TheNescios]

PEX-A does have some benefits over PEX-B, and I considered this option, but, as the existing PEX in my RV is the B series and PEX-B can be found not only in the big box stores but I've also seen it in the little independent hardware stores you find along our journeys so I went with PEX-B.
But I agree, if I was going to build something from scratch like a home or shop the PEX-A would be my preferred choice.

The flex hose isn't horrible if it's used correctly with the fittings & clamps designed for it - the issue is using PEX fittings & clamps on non-PEX materials.
As an FYI, there was a post I ran across on here and I apologize for not being able to recall who posted it, but they shared that they'd used a good quality hose clamp to do a repair on the PEX to Flex when the Flex connection failed with good results. Made a lot of sense to me as the hose clamp is wider and is designed for Flex type tubing so I'm now carrying a half-dozen good quality hose clamps "just in case".