12v water pump hammering

[SC_camper]

We have only used our water tank and 12 volt pump once in 2 years, always have city water hookup. Upcoming trip has no water at site so I wanted to sanitize tank and lines. Yesterday I filled the water tank with water and some bleach. Turned on the pump, ran all the faucets, shower ect. Everything worked normal. This morning I drained the tank, lines and water heater. Then started filling back up. Turned the pump on after 5 minutes or so, I had water out of the faucet but it was pulsating and vibrating the lines. After checking tank monitor and seeing it was still on E, I noticed my water hose had a kink and tank had low water level. Un-kinked hose and let the tank fill.

I let the faucets run, hot and cold, until Im getting no more air. Now the pump is hammering and the water lines are vibrating and banging. While looking at the pump, I noticed it now has a small drip where the two halves of the body come together. But only when water pump is running. I hooked up city water connection and have no vibration or leak. Is there anything else I can do or check before I replace the pump?
Is it worth trying to get a rebuild kit or gasket for a WFCO Artis PDS1RV25 pump? PPL has them for $50 but we rarely use it.

[Almot]

SC camper wrote:
What happened between yesterday and today to cause the problem?

Bleach cleaned/unsealed the crack between two halves of the pump housing. (Or it unsealed by itself, under pressure). This is why you see now minor water leak where 2 halves come together. If water can leak out, air can sneak in and cause hammering. Could be air pockets in the system as well, but obviously there is a leak if you see a leak.

With a bigger crack the water would've stopped flowing completely, while pump still running (had this once).

Tighten the screws holding the two halves together. If they are tight, open it, clean the crack and close again, check for possible membrane damage while you're at it.

[All_I_could_aff]

Also possible small amount of air is being sucked into the pump from the leak, creating a continuous supply of air to cause hammer. Kind of like the way old Diesel engines from decades ago with mechanical pumps could suck in air

[MEXICOWANDERER]

A chamber that isn't full will cause pulsing. Lots of it. Fix the leak and the chamber will fill. I use a 3" standpipe to minimize pulsing. It works.

[jodeb720]

A few years ago, I had asked DW if everything was switched off before we put the rig into storage. She said yes, and I wasn't dumb enough to check it. I also didn't have a battery cut off wired in.

Well, you can tell what happened, I opened my drain valve, drained out all my water, and then put the rig in storage.

I was in a hurry and forgot the keys to give it a once over. Unfortunately, the water pump wasn't switched off and something caused the line to be unpressurized and well, the pump started running.

It ran until one two of my Golf Cart 6 volt batteries were dead (I mean dead, as in a door knob).

Now when I run the pump, I get pulsation from the taps on the sinks - but not all the time. Just some of the time. An expansion tank would fix the problem, but I have other projects and not enough time to get to all of them.

Just my experience. I don't know what happened that's caused the pump to pulsate, but I do know an expansion tank would solve the problem.

[2oldman]

I guess I do need to get out more.

[SoundGuy]

2oldman wrote:
That's a 'knock off' pump I've never heard of.

You need to get out more as the ARTIS pump has been in production for several years now, stock in my 2014 Coachmen Freedom Express built in 2013, also stock in Apex trailers. I replaced mine with a Shurflo Revolution I happened to have on hand but still use the ARTIS as my fresh water transfer pump.

[2oldman]

That's a 'knock off' pump I've never heard of. Perhaps it is failing given you've eliminated every other possible cause.

[SC_camper]

Dont have an outside shower.
Ran all faucets/shower for several minutes each on city water. No leaks, no air, no pulsation. Everything flows perfect.
I let the water heater fill first.
The sight glass on the fitting going to the 12 volt pump is clear with no bubbles, with pump running or not.
The pump only leaks while it is running.
Dont understand how everything worked perfectly yesterday and problems today.

[2oldman]

SC camper wrote:
What happened between yesterday and today to cause the problem?

Is the HW tank full? You do that first.

Accumulator tanks help too.

[Lenny_K]

If you have hammering with the pump on, run your outdoor shower to get the air out of the system.

[SoundGuy]

SC camper wrote:
Going out now to check for leaks at the pump and will run the 12v pump again and see what happens.

If you're not getting a steady flow of water but don't see any apparent leaks I'd disconnect the pump from the FW holding tank and see if it will prime properly from a jug of water. If it does you have an issue with the feed from the tank, if not you have a leak elsewhere.

[SC_camper]

SoundGuy wrote:

SC camper wrote:
I can see the water coming out of the faucet pulsating too.

What happened between yesterday and today to cause the problem?

Air in the system ... and it sure shouldn't take anywhere near 5 minutes as you described in your first post to get the pump to prime, purge any air out of the system, and deliver a steady stream of water.

The 5 minutes is the time I had waited for the fresh water tank to take water. I found my garden hose had a kink and wasn't adding much water. When I was first running the pump, the fresh water tank had low water. I have tried again with full tank.

Ive had the city water hooked up for a while now. Going out now to check for leaks at the pump and will run the 12v pump again and see what happens.

[SoundGuy]

SC camper wrote:
I can see the water coming out of the faucet pulsating too.

What happened between yesterday and today to cause the problem?

Air in the system ... and it sure shouldn't take anywhere near 5 minutes as you described in your first post to get the pump to prime, purge any air out of the system, and deliver a steady stream of water.

[SC_camper]

The pump outlet has a foot of flexible hose in a loop shape. The inlet has a flexible hose going through the floor.

I can see the water coming out of the faucet pulsating too.

What happened between yesterday and today to cause the problem?