Pressurized Water Pump replacement?

Madathlon · January 28, 2011, 03:06 PM

OK after a search through here and on the web I can NOT find info on location a new Water pressure pump for the Air type pressure system.

So friends I need your help on locating one.

Or a good plan on conversion. Here is one plus, I have an OLD slide in that has a tank and what I think is a simple low pressure pump built into its water tank. It feeds a single water faucet. enough for drinking water.

ibdilbert01 · January 28, 2011, 04:02 PM

The original pump would of just been an air pump with a built in pressure sensor. I'm not sure of any "new" replacement models on the market, though I've never looked.

Converting to a on demand water pump such as a Shurflow model is fairly straight forward.

You simply stick the pump in between the water tank and the water line that feeds the rest of your coach. You'll need to make sure to vent the tank to atmospheric pressure. The pumps are totally automatic by water pressure sensing. Meaning when you turn on the sink, the water pump will automatically turn on. However you'll probably want to make sure you have a switch thats fairly easy to get to to turn the power off in case of leaks.

Madathlon · January 28, 2011, 04:10 PM

Would I need to make a bypass for shore water supply? Or would the OEM set up still work?

ibdilbert01 · January 28, 2011, 04:16 PM

I'm not really sure how OEM was configured. On mine I have a check valve on the hose going to the shore water hook up. This prevents the pump from sending water out the shore hook up, and the pump has its own valve that prevents the shore hookup from back feeding through the pump and into the water tank.

DaveVA78Chieftain · January 28, 2011, 07:33 PM

The original air pressure system used a air compressor that had a pressure switch which basically turned the pump on a 20lbs PSI and turned it off at 40lbs PSI.
Here is a link to information for one that was used on a airstream trailor:

Grover Pump 1393

You would have to adapt something like a air horn or air ride shock compressor in order to retain the original system approach (same concept as a pressurized accumulator)
http://motors.shop.ebay.com/i.html?_nkw=air%20ride%20compressor&_dmpt=Motors_Car_Truck_Parts_Accessories&_fcid=1&_jgr=0&_localstpos=22657&_sc=1&_sop=15&_sticky=1&_stpos=22657&gbr=1

You would have to find a pressure switch rated at 20lbs on and 40lbs off.
Original system used metal stroage tanks. Modern system use plastic tanks.

The alternative is to convert to a modern water pump system that uses a pump like shown in the post above.
You neeed to look at a modern system configurtion to see what is needed to do a conversion. Both output and fill sides have to be modified.

Dave

Madathlon · January 28, 2011, 07:38 PM

Has anyone ever posted the set up they made to get it to work? Drawing? Photos?

DaveVA78Chieftain · January 28, 2011, 09:13 PM

If you put the term "pressure water" in the search box you will find threads talking about how to convert the system.

As far as what your trying to accomplish, here is a link to a in-depth description of a modern RV plumbing system:

Water, Water, Everywhere

Dave

Madathlon · January 28, 2011, 10:15 PM

I have found many compairing and asking for help. But none seems to have a direct answer. As in like how they did it. I have lots of experience in wiring's and drivetrain. But on water systems and couch repair I'm in the blind. Some one out there has had the same issues, this I know, But What steps did they take in the change over from Air to on demand. I need some real good solid info on what is needed to be done, Not just add this pump. I know that there will be a vacuum issue then. But how was this solved?

DaveVA78Chieftain · January 28, 2011, 10:54 PM

Closest I found to a step by step is here: http://www.classicwinnebagos.com/forum/index.php?topic=1807.0

I have never done this myself. They had stopped using the pressure system by 1978. While I understand how it works, I would have to look at the actual installation a determine where to place a modern style water pump just like you will. You would have to leave the orignal air bleed line open for venting. You would still fill the metal storage tanks the same way you do for a pressurized system. If your rig does not have city water connection, it would have to be added in on the output side of the new water pump (pump should have a one way valve in it to prevent city water being forced back out the fill/vent line). Even though the pressure system using a air compressor is no longer used, many add accumulator tanks to help maintain pressure to a modern RV system. If you have ever lived in a well/septic home, it most likely had a accumulator installed.

Dave

Oz · January 29, 2011, 04:26 AM

Only a very few people have done this conversion and nobody has made a step-by-step instruction manual on the topic, including all parts and materials needed, sizes, lengths, sources, diagrams, photos, etc. At least, not that I can find... anywhere. If you happen to find the direct answer you're looking for somewhere, please share it with the rest of us. Otherwise, the closest thing you're going to find is how to install a replacement, on demand system, which means a replacement tank designed for on-demand, like my rig has, and it's even hard to find any info which covers every detail of that complete process even though it must have been done by thousands of people already. But, from that info, you can look at the set-up and figure out how to modify your tanks so they are like on demand tanks (which is the only real big modification needed).

As for the vacuum issue, there is a vent tube on the top of water tanks designed for on-demand. My system doens't have an accumulator tank, just the pump and I always have instant, consistent water pressure.

This is a DYI project with no complete manual already written about it. What we do with projects like this is to get as much info as our members have to offer, do additional research on our own, get a starting point and then start working on it, asking questions along the way. So, when you do this project, please be sure to write down evey step, list all the parts, take measurements, photos and make diagrams and create a DYI Article, like Dave's "Chrysler Electronic Ignition Systems" and submit it in the Member Articles so others who want to do it in the future will have it for reference too. It'll be a first and a very sought after source of information.

Again... sooooo many of your questions, past, present, and future are covered in the Winnebago Eyebrow Coach Manual or it would be an excellent reference as to the components, etc involved and, the other coach manual, which covers the newer systems, has good diagrams and concetpual info with which to compare with.

Madathlon · January 29, 2011, 01:13 PM

Then I will need to do it and make a basic manual

I found out that I can use the old air pressue inlet for this, so part of the manual is beginning to form up.

So I guess I will have to fully learn about pressure systems and do a photo diary and make a manual.

So wish me luck and wait for a manual to appear, Oh could I upload it as a PDF?

Oz · January 29, 2011, 03:48 PM

.PDF can be uploaded to a Gallery album and that way, it's easily downloadable by anyone.

JDxeper · January 29, 2011, 09:51 PM

I am ready to convert the system in the 68 F17 to an on demand system. Have it all planned and most of the replacement parts. Started removing some of the old air system today. Need to do some wood replacement before going farther. Have pump, poly fresh water tank, city hookup with flow control valve, fresh water tank fill vented, pex (red and clear), cutter, pex tool, new kitchen faucets, water heater bypass, drain valves. And a rv-water-system diagram.
http://bigdiscountrv.com/rv-water-system-diagram.htm
JD
And room for forgotten parts. i??

DaveVA78Chieftain · January 29, 2011, 10:44 PM

JD,
If you have not done so already, you might want to read over the following web page to see if you missed anything. It gives the details for the different components.

Water, Water, Everywhere

Dave

Lefty · January 30, 2011, 01:02 AM

Our '76 Winnebago had the air pressurized system, and had been converted to a modern pump.

I dont own it anymore, but maybe can provide you with clues as to how it was done.

On mine, the fresh water tank was mounted in the rear, inside the rear access door, under the kitchen sink (mine had a rear kitchen and bath).
The original fill point was used, Mine had a fitting on it also that looked like the same kind found on radiator draincocks, when camping with water hooked up, you kept it screwed shut, to prevent it from spewing water with the tank full, but when filling the tank, or when using the water system without city water hooked up, you unscrewed it to open it, providing the necessary bleeder for air to the tank as water is used, .
Water from the filler went down a hose to a fitting on the tank (the inlet), then another hose attached to another fitting at the base of the tank (the outlet), from there, it went directly to the inlet side of the new pump. Then another hose attached to the outlet side of the pump, and went about 4" to a T-fitting. One hose from the T-fitting supplied the cold water for all of the coach (the toilet,cold side of bathroom sink,shower, and kitchen sink), the other hose on the T-fitting went into the inlet side of the hot water heater, Then another line exited he outlet side of the hot water heater and supplied the hot water to the kitchen and bathroom.
As for the wiring, it appeared they re-used the original 12v wiring for the air pump, and just hooked the new pump to it... the new pump worked using the original power switch located inside, on the upper kitchen cabinets. Pull for "On", push for "Off"
The original pressurized airline that would have went to the tank, was removed and the fitting on the tank had been replaced with an 1/8" brass screw in plug.

Hope this is a bit of help.