I have a number of rain water tanks which I use to water my vegetable garden during the summer. I have a cheap water pump that has been working faithfully for the last 4 years but this year, when I turned it on for the first time, I got no pressure regulation, the pump was running flat out and water was pouring out of the electrical control box. Not cool!

The electrical control box is the size of, say, three decks of cards stacked up. It contains the electrical terminations for the power cable and the pressure switch. The pressure switch is used to set the operating pressure of the water pump.

To provide the capability of measuring the water pressure and switching the power to the motor there is a mechanical connection between the water and the electrical components. This mechanical connection is provided by a rubber diaphragm which allows the mechanical components to move but does not allow the water to escape. Well normally that is true. In this case the issue was that the diaphragm had perished and ruptured. Hence water flowing vigorously through the electrical switch gear.

I priced a replacement pump and a replacement pressure switch. The switch was the price I paid for the pump in the first place and a replacement pump was twice what I had originally paid. So I decided to have a crack at fixing the thing.  This instructable is what I found and how I repaired it.

Step 1: Removal of the pressure switch

Having determined the there was a problem with the plumbing at the pressure switch it had to be removed. The main power cable comes into the pressure switch and then back out to the motor. The pressure switch is screwed into the outlet manifold and the only way to remove it is to disconnect the cable between the motor and the switch.

The photo below was taken, initially, to document where the wires were terminated.

Having recorded the electrical connections, those between the pump and the pressure switch were removed so that the pressure switch could be unscrewed from the manifold.

Maintenance activities were then relocated from the garden to the workshop.
Good luck with your repairs. The expense of replacement is what prompted me to try as well. I'd even give replacing bearings and seals a go after the experience of this repair.
I didn't realize that fixing a pump would be so expensive. I'll have to give this a try and see if I can fix my pump. If it doesn't go well I can just call a repair man, but I can at least try. it's just a pump, right? <a href="http://www.globalrewinds.com.au" rel="nofollow"> http://www.globalrewinds.com.au</a>
Good article, and great job!
Thank you sir. I try.
I like the duck.
He's a bit of a character that's for sure.
Excellent Job! Clear, concise and well made 'able.
Thank you. 8D
you are welcome
great job on repair , tip buy a box of round tire patches from a auto suppy or parts store <br>they will work, come in diff sizes i have used these for diff repairs <br>god bless
Nice tip. I hadn't considered that technique. Thanks
This is awesome! You should post a picture when your veggies come in, I bet you will have even more!
I think I'll do that. Thanks.

About This Instructable


21 favorites


Bio: I'm a computer systems engineer living on an acre in the Adelaide hills of South Australia.
More by FieldingBlue: Bushfire Preparation - Simple Gutter Filler Simple Bird Nesting Box,... Tube, err um,.. thing! Arduino based Door Minder for draughty houses.
Add instructable to: