Water Pump

[freckvan1]

Afternoon All ,
Having had my van for last twenty four years , 1984 DG W/C , have decided after stripping interior to utilize the underslung water tank which we’ve never used .
Obviously tank needs a damn good clean and new fittings .
I am going to buy a new water pump and have become a little confused with looking at examples on internet which appear to have an expansion tank/trap fitted in line with pump . The system previously was just a pump and nowt else .
Can someone explain how there system is set up please and is there really a need for expansion trap/tank .
Pump I’ll be getting is self priming as pump will be near C pillar off side and water tank is near side .
Atb,
Chris

[Jeff J]

No tank on my Autosleeper, just the same set up as you have. I had to replace the pump several years ago but never had problem getting a replacement, though I can't remember what make it was. If your tank is the same as mine then gravity will force the water through the pipe across the van and up the other side until it reaches the same level as in the tank then the pump just has to lift it to the tap. My tank just has vent holes in the top to allow for expansion when full.

[Mocki]

The pumps you are looking at will be for a pressure system, the expansion tank is the pressure vessel , there will be no switch on the tap, you open the taps and pressure makes the water come out, when the pressure in the system drops the pump pumps , thats not what you need, you simply need to search for a “whale” pump, either submersible or inline depending on your set up , go and buy “puriclean” to clean with, not baby bottle fluid, whic isnt designed for the job