Dual water pump upgrade in 85 Pace Arrow

[Bugman114]

Howdy yall. I had been needing to replace the pump and some of the plumbing in my pace arrow for a while now, and finally got around to it. When looking for pumps I tried to find the highest pressure and highest flow pump I could find, my goal was for the system to be as much like home as possible. Well I finally decided to try out an idea I've had. I bought 2 4008 shurflo pumps. I made a bracket to stack them on top of each other, T'd the suction line, T'd the output lines of the pumps, and ran a line to a large expansion tank from homedepot, which makes an excellent accumulator. Then from the tank to the pressure line.

It worked exactly how I thought it would. I turned on the bathroom sink, the kitchen sink, the shower, held the toilet on and the pressure didn't lower at all. Plus, I can run the sink on for 20-30 seconds with the pumps off, since the expansion tank acting as the accumulator is so big.

The wiring was pretty easy too. The pump wire was already a 10awg wire, on a 15 amp fuse. So I T'd the power line, and ran one to one of the pressure switches on the pumps, then from the pressure switch to a universal relay sold at any parts store (used for horns or lights, etc). Then ran both the power wires from the pumps to the load terminal on the relay (#30). So basically I have a single pressure switch from 1 of the pumps activate a relay that activates both pumps so they come on at exactly the same time. I used the relay because I wasn't sure if a single pressure switch could handle double the load it was intended for, so the relay takes the load instead. I'll post some pictures as soon as I get them. Just felt like sharing if anyone was as frustrated as I am about how when someone's in the shower, using the sink just kills the pressure, lol.

Another interesting thing I learned is that the old grey water lines it came with are polybutylene, which they do not make a cement for. The only option is PEX clamps, or the easier option, are poly to CPVC conversion shark bites from homedepot. The original aluminum clamps on the poly tubing had failed for some of the poly tubing, so this was the best method. I replaced as much as I could with CPVC cemented together, and used a conversion sharkbite for the areas that were impossible to get to.

[Bugman114]

SCV jeff- I was just tired of one pump not being able to keep up with having 2 things on at once. If someone's in the shower, using the toilet or faucet became a hassle. Plus I plan on upgrading the water tank to a much larger one in the near future. When I go camping it's only with 1 or 2 other people, so the water usually lasts us 2 or 3 days, and if we run out And wherever im campiclg doesnt have hookups, there are pilot/ flying J/ loves truckstops everywhere and most have free water outlets that I've filled up the water tank with many times.

ArchHoagland- according to the pumps they are producing 55psi. I haven't tested it, but i think I'll hook up a gauge somewhere and find out for sure. Thanks for the suggestion

tderonne- I didn't even see that setup, but i got all my parts cept the expansion tank, off amazon about a year ago. I only spent around $200 for everything. That setup most likely would not have fit in my RV anyway. If you look up at the pic of my bathroom, the pumps are in the space next to the sink, under the cabinet, lol. You can see from the pic of the pumps how tight everything was. I thought about moving the pumps under the bed, but that would have taken more plumbing and the loss of space I plan to utilize with a larger water tank.

[tderonne]

So you made one of these:



But this one costs $500!

[ArchHoagland]

I'd be curious as to how much pressure you are developing.

I have a hose bib in my water bay that I can attach a pressure meter to and see how much pressure my water pump is producing.

[SCVJeff]

I'm not sure why you would want to deliver that kind of volume with the current of 2 pumps and a 40gal tank that you could be refilling every other day or better. The Oxygenics shower head delivers residential power at a fraction of the volume, current, and price.

I have a mobile home supply clues to me where I found the OEM clamps and joints, after age got to a few.

If I didn't know where my 27Y was I'd swear that was it

[Bugman114]

ScottG wrote:
Those aluminum clamps were the downfall of Qest tubing. They were used the most but sometimes the more reliable copper bands were used and the tubing held up fine. But the alum. clamps would stretch and fail without warning and it's best to get rid of them no matter how long they've lasted.

I want to replace it all asap, I just need it working for now. I'm keeping a close eye on the remaining fittings I do have. Thanks for the response 😄

[Bugman114]

Here's the RV:





Here's the bathroom shortly after finishing everything. You can see where I mounted the expansion tank, it's pretty much out of the way with minimal loss of cabinet space:




The pics aren't great, as I should have taken some before I installed everything, my bad. But you can kinda see the two pumps here. The line you see is the one coming from the tank. I used a brass T to connect both pumps to it:

[ScottG]

Those aluminum clamps were the downfall of Qest tubing. They were used the most but sometimes the more reliable copper bands were used and the tubing held up fine. But the alum. clamps would stretch and fail without warning and it's best to get rid of them no matter how long they've lasted.