water tank pressure system doesn't work

[MustangGT221]

Sent: 7/27/2004 12:08 AM

Hey guys,

I have a 72 winnebago (brave) which I just picked up. It has a steel water tank and is suppose to have the pressurized system. The air compressor seems to have been removed (it's suppose to be next to the water tank isn't it?) and nothing happens when I flip the switch on the cabinet wall.

I was wondering what would be a good solution to get my water system working, should I get a water pump and connect it, should I get another air compressor...any ideas?

I would guess the best idea would be to get an inline water pump and put it inline with the outlet pipe, but I have no idea where to get one or which one to get....any suggestions?



The little "control center" i'd call it, on the cabinet by the rear beds, has a switch for the water tank, holding tank, and the air compressor. When I flip the water or holding tank switch, a "0" illuminates on the display. When I flip the compressor switch, the light comes on saying "pump", but nothing happens as theres no air compressor.

Are those water/holding tank switches suppose to tell you how much each tank has in it, hows it work?

I put more than 1/2 a tank of water into the water tank, and put that water tank switch on and it still said 0...

[70winnie]

Sent: 7/27/2004 12:46 AM

I'm in the process of placing all new plumbing in my Winnie.  Like you, I have a tank which used to be pressurized.  I purchased a Shurflo pump, 2088-422-444, for $73 from a local RV store.  Once I get the system all connected, I'll tell you exactly what I used (which hopefully will make it easy on you).  Should be in the next week or so.  If you don't hear from me in 2 weeks, please post a reminder!


Also, I found this page very helpful:
http://www.marxrv.com/plumbing/plumb.htm

[70winnie]

Sent: 7/31/2004 10:47 AM

I finished my plumbing earlier this week.  Because I built an entirely new system, not all of what I did is applicable to this conversation, so I'll try to stay focused.

The good news is, once you know what you need, it's really not difficult to put it all together.

The first issue with converting from my pressure system to a pump system was on the intake side of the steel tank.  The original tank fill was connected to the tank with copper pipe and compression fittings.  Leave this original fill intact if you can!  Otherwise, you have to install a new fill system, which I did because I moved my tank to a new location, and destroyed the old fill in the process.  As a result, I had to replace the 3/4" compression fitting on the intake side of the tank with a 3/4" pipe thread fitting, which connected to a 0.75"-to-1.25" pipe thread coupling, which connected to a 1.25" pipe thread to 1.25" barbed fitting.  The barbed end is connected to 1.25" gravity fill hose, very similar to that used on swimming pool equipment.  The other end of the hose is connected to a new gravity fill, which is basically a door in the side of the motor home that you pour water into.

You will insert the pump shortly after the output side of the tank.  In my Winnie, evidence suggests that a PO did this by cutting a section of the copper about 3 feet long, inserting his pump in the middle, and putting about a foot of rubber hose on each end of the pump.  The hose was connected to the original copper tubing with hose clamps, and you'll need a fitting to attach it to the 1/2" pipe threads on the input and output sides of the pump.  The pump specifies that at least one foot of flexible hose is required on each end to prevent proplems (leaks and noise) caused by the vibrating pump.

My pump recommends a 50 mesh strainer, installed on the input side to keep solid materials from the tank from ruining the pump.  It screws directly onto the pump input side, so you can attach your rubber hose directly to that.

If you want to be able to hook up to city water when it's available, you'll need a separate "city water fill" to feed the plumbing after the pump outtake.  The pump isn't designed to handle the 100+ possible PSI pressure on the city water side, so hooking up city water to the old water fill could be detrimental to the pump.  My guess is that the rubber patch hose probably couldn't handle it, either.  Be sure to get a fill with a built in check-valve and pressure regulator!  Otherwise, you'll have to buy those items separately and installing them will require additional work!

Installing a new city fill involves drilling an appropriately-sized hole (about 2.5") into the side of your RV, attaching the new city fill (a few bucks) over this hole with screws and butyl tape, and then patching it into the copper tubing anywhere after the pump.  I can't give you detailed instructions because I attached my fill to all-new PEX (plastic) plumbing, but it shouldn't be very difficult.  The easiest solution is probably to use rubber hose (like you did around the pump) and patch in some sort of "tee" fitting to branch off to the new city fill.

Finally, you'll need to run a pair of wires from your house battery to the pump.  The pump instructions will tell you exactly what to do, including what size wire to buy and what size fuse to install along the positive (+) wire.  You'll also want to install a 12v switch along the wire so you can prevent the pump from coming on due to water line pressure changes when nobody's actually using the system.  Since your control center has a switch for compressor/pump, you should probably use that one... but make sure the wiring/fuse to that switch conforms to the specs listed on your pump!

Ultimately, I plan to add an accumulator tank to my system, as explained on Mark's RV website (link above).  This allows the pump to come on less often.  For example, it won't come on in the middle of the night when you flush the toilet one time.  Cost is about $30, and you can patch it in the same way you'd patch in the new city fill.  Again, see Mark's site for instructions.

I hope that answers your question.  Need any clarification, let me know.

[MustangGT221]

Sent: 8/5/2004 9:56 AM

OK so I think I've decided to just put a water pump in the loop. Everything is already plumbed, I can run water through the system from my house (well water, not city water) without leaks. I have two sinks, toilet, and a shower for my RV, the sinks will probably not be used at the same time. I was wondering what GPH rating I should be looking for in a pump, and what shutoff PSI should I go with? I was thinking the 35-40 psi range is best....

My RV has a shrader valve above the water fill coupler to put air in the tank. I pressurized it to about 17-19 psi and I got great water flow to the sink, but the air pressure will leak out slowly. It doesn't seem to be a problem with the 40psi of water pressure though, just the air.

Edit:

Well it turns out that my Uncle has a pump he is willing to give me. It came off of an RV that he had...so I bet it will work just fine.