2019 Hawk Plumbing Parts

[Charlie]

I'm working on the plumbing in my 2019 Hawk, and trying to figure out what the components actually are.

Doing this because I noticed that the lower end of the plastic tee on the water heater fill connection had been cross-threaded at the factory, and I want to fix that. I was really surprised that it was even water tight.

I was able to find the tee, it's from the Zurn QickTite PEX line of fittings. This is screwed into what I assume is a standard FNPT thread on the water heater.

So, I gather that these QickTite compression fittings just happen to have NPT threads, so that you can throw away the compression nut and run it right into the water heater. But it seems like a strange mix of systems, and sure enough I'm struggling to keep it from leaking slightly. I saw that FWC had used a whole lot of teflon tape, so I will just keep adding more wraps to see if I can get a tight seal. But being plastic, there's a good chance of ruining it if it is screwed in too tightly.

So, isn't there a brass fitting that would be a better match for the water heater fill?

Also, what is the trade name for the armored water line tubing with the crimped end fittings? Those fittings are really solid, with the enclosed rubber washers. Connecting these to the plastic fittings seems pretty flimsy; aren't there brass or steel fittings that could be used instead?

I've attached a picture of what I'm talking about. I also pointed out the check-valve which had failed and prevented the water heater from filling. They are easy to get at RV dealers and online, and it was an easy fix.

 

[BFH4N]

You could replace the plastic parts that are visible in your pic, and probably others elsewhere, with brass fittings. The hose ends will screw right onto the NPT pipe threads. Since the seal is made by the rubber washer, the threads don't much matter. While the plastic parts do seem kind of hokey, it's theoretically a valid choice. Cheaper and lighter than brass. As long as the hose end isn't cross-threaded (which yours was), it should be fine. It is very easy to get cross-threading if you are not careful when you are joining plastic and metal parts.

That plastic tee does seem like an odd choice, though. I suspect that the threads are IPS (straight) rather than NPT (tapered). Same diameter and thread pitch, but IPS threads are not designed to seal. You can screw an IPS end a little ways into an NPS fitting, but it won't seal. You might be able to achieve a crude seal if you put a lot of pipe dope or teflon tape in there, which apparently is what FWC has done, but it's not the way pipe threads are supposed to work. It's an invitation to a future leak in a high-vibration environment like an off-road camper. The hose end will work OK on that fitting, because it screws equally well onto the IPS or NPT threads.

So why choose a fitting that is designed for a totally different kind of pipe, with the wrong threads on two of the three ends, throw away all the hardware that comes with it, to use it inappropriately?

Though it is an odd part, you can probably find a tee like that somewhere. Check Amazon and Ebay. Just be sure it has NPT threads. The ideal part would have male NPT threads on the ends and female NPT on the side. Then you could use a nipple and a street elbow for the rest of it. If you can't find that, you can make it up from more common brass parts.

Good luck...

 

[Charlie]

Thanks Bernard, I knew you would know all about plumbing. I’ve ordered a brass NPT tee, which should do the trick.

 

[BFH4N]

So, will you be able to elliminate the coupling and elbow and just connect the hose right to the tee?

 

[lost73]

Not meaning to hijack thread. Just picked up our 2020 Hawk last week. Is there is plumbing schematic that shows the location and plumbing between the hot water heater, sink, fresh water tank, etc.? Thanks for the consideration. Picture for emphasis.

 

[CougarCouple]

Hi Charlie
Those hoses which you mentioned are “Braided flex connectors “ if I remember correctly. Come in a variety of ends. Compression thread, pipe thread and different lengths.
Used to connect sinks to angle stops, toilets to angle stops. That’s where I’ve normally seen them.

Russ

 

[Charlie]

Hi Charlie
Those hoses which you mentioned are “Braided flex connectors “ if I remember correctly. Come in a variety of ends. Compression thread, pipe thread and different lengths.
Used to connect sinks to angle stops, toilets to angle stops. That’s where I’ve normally seen them.

Russ

Thanks Russ. I also found them listed as “Faucet Hoses”. I haven’t yet found one with identical NPT compatible threads on both ends, which is an unusual application, but I don’t need to buy the hose anyway.

 

[Charlie]

So, will you be able to elliminate the coupling and elbow and just connect the hose right to the tee?

Indeed, I just replaced the plastic parts with a single brass tee. So far, so good, seems like a much more sturdy arrangement. Someday I will replace the other few plastic parts with brass.

I also moved the pump forward a few inches. The line from the water tank to the pump inlet was ridiculously tight.

Also, for those worried about digging into the plumbing, it is really quite easy to get in there, at least on a front dinette configuration. Remove the furnace grill and silverware drawer, take the front panel screws out, wiggle the panel around, and rest it between the dinette seat and the ledge above the right rear compartment. Photo attached.