Water pump problem - Micro Minnie

KGs2108DS · 03-28-2020, 07:58 AM

un-winterizing micro Minnie yesterday, and 12V water pump not pumping. everything works just fine w/city water hook up. 12V water pump running normally, but not pumping any water. all valves in correct positions. d/c water inlet and outlet hoses, cleaned in-line filter, tried to suck up water from bucket (as in winterizing), no water movement. last fall I used compressed air 30lbs to winterize. followed several DIY videos on the topic very carefully, but now wondering if pump may have had a bit of residual water and frozen. looks pretty easy to remove and replace. can it be rebuilt? appreciate any further thoughts on how to trouble shoot. Or whether rebuild or replace - and where to purchase.

**creativepart** · 03-28-2020, 08:24 AM

RV water pumps are self-priming. And most are easily rebuilt. Look on the pump for the brand name and model number - you can use a smartphone to take a photo of the label - then do an online search using that info. YouTube has lots of water pump repair videos.

Normally, if seeing your problem after dewinterizing, the problem would be that you have the valves set incorrectly. But if you’ve directly connected a water source to the water inlet and it won’t pump that would seem to disprove that issue.

Goodspike · 03-28-2020, 09:22 AM

Quote:

Originally Posted by KGs2108DS

last fall I used compressed air 30lbs to winterize. followed several DIY videos on the topic very carefully, but now wondering if pump may have had a bit of residual water and frozen.

I don't know if that's what happened, but that has been my concern. My practice has been to have the pump suck in a bit of antifreeze (maybe 1/4 gallon) after blowing out the lines figuring it protects the pump and the lower level lines near the pump.

Morich · 03-28-2020, 09:28 AM

Are you lines clear enough to spot water is actually getting to the pump if you add some pink anti-freeze? I would want to know that as a first step as mine are semi clear lines. If not look for valves in the wrong position but if water is getting to the pump, I might first take the little filter off and make sure water runs out and then check for problems on the filter before removing the pump.
If the pump froze bad enough to fail, I would expect to see damage. But assuming no problems spotted so far, I would take the pump out, check it runs normal and then look at the front end to see if it comes apart. Those I've used are pretty simple to remove and take a look at the impeller as it may have degraded and simply fell apart or something as simple as retaining nut has come loose, leaving the motor to spin but not the impeller.
Possible a bit of construction debris finally has clogged something? Things can float around in the holding tank for years before finally clogging some point.

KGs2108DS · 03-30-2020, 10:47 PM

UPDATE - replaced water pump. new pump works just fine, BUT will not shut off. I cannot find a leak anywhere, so I'm guessing there's an air leak somewhere (hopefully in connections to new pump). the filter is suspect (wishing I'd have bought a new filter and small pipe it's attached to, while at RV store). I've tried teflon tape of all connections and didn't help. at one point the pump did shut off a couple of times, but for. the most port runs slowly, and I can hear either an air leak or air/water leak below the flooring. have looked down w/a mirror and light, and inspected belly from outside - no apparent leaks. as I said earlier I winterized with compressed air at 25lbs pressure. guy at RV place said you've got to use 50lbs to get ALL the water out. what are the chances that there is some type of leak below the floor in the tube coming from the water tank up to the pump? thanks! I repent of ever using compressed air to winterize again!! will gladly go through the mess of antifreeze next fall.

Goodspike · 03-30-2020, 10:59 PM

Quote:

Originally Posted by KGs2108DS

UPDATE - replaced water pump. new pump works just fine, BUT will not shut off. I cannot find a leak anywhere, so I'm guessing there's an air leak somewhere (hopefully in connections to new pump). the filter is suspect (wishing I'd have bought a new filter and small pipe it's attached to, while at RV store).

I would assume you would see dripping from these locations, but have you checked the two low point drains and also the exterior shower? And in that regard, did you remember to blow out the exterior shower when you winterized? Assuming your exterior shower is behind the main shower, as mine is, a leak there would be difficult to detect. Another place for a leak would be the water heater plug, but that probably wouldn't be so extreme as to have the pump keep running.

Unless you're compressor wasn't limited to 25 pounds as you thought, I really doubt it was from using compressed air. But again, after blowing out I do suck in antifreeze to the pump just to clear it of water.

KGs2108DS · 03-31-2020, 08:08 AM

thank you Goodspike! pretty much yes to all...when I winterized I did open low point drains, exterior shower as I was blowing air through system. hot water plug is not leaking. no doesn't seem to be any dripping anywhere that I can see. air compressor is two stage gauge, and I adjusted line pressure to 25-30lbs. the sound (low hiss) of air leak does seem to be coming from pump area, OR just below this in sub floor. I think the next thing I'm going to do is replace the pump filter assy - it appears there could be a very small crack in the bottom of the filter housing.

Morich · 03-31-2020, 09:00 AM

You mention the filter crack, I find that can be a problem after we have worked on the pump as we may not help ourselves at times.
My mind kind of says things like that filter should hang down, but if I think about it as a factor in winterizing, I'm WRONG. Far better to leave it the way I found it installed from the factory with the base of the filter up, so that when draining the water runs out, not stay in to freeze!
Result might be to look at how your filter sets and think how the water would get left in and freeze. That could be a quick and easy solution.
But assuming it is not quick and easy, I might suggest trying a soap test as a way to tell if the connections are leaking. Certainly not going to be able to reach lots of them but easy way to test those you can reach and less work than taking them apart to add tape.
soap testing a lot in aquarium work and find it takes a bit of practice/thought to get it right as we have to look for two types of leaks.
I want a really thick soap solution that will to the parts long enough for small bubbles to build to a size I notice for slow leaks but I also want to watch carefully as I swab it on as a fast leak may simply blow the solution off and never build a bubble.
A last resort might be to put the city water on and look for leaks but that is not nice if it's spraying water lots of water out under the cabinet, etc.

KGs2108DS · 03-31-2020, 09:06 AM

thank you Morich!! now that you mention it, the water filter was angled downward. I just got off the phone with service manager at Harrison RV in Jefferson IA, where I bought my trailer - great folks by the way!! I'm going to replace the filter assembly. He felt is was very unlikely that a leak would occur in the sub-floor / belly area as long as the tank was drained - which it was. BTW, w/city water every thing works just fine, no leaks that I can find. thanks for the soap test idea. I recall as a kid working in a tire shop, we tested flats and the beads on the tire for leaks w/a soap solution.

Morich · 03-31-2020, 10:29 AM

Sound like you are real close to solving. When I think about that flimsy little filter and setting with water over the winter, I get the idea it might be a problem.

KGs2108DS · 04-02-2020, 03:33 PM

Well friends, quite an adventure. hopefully a final question on the 12VDC water pump apparent vacuum leak. I attached city water hose for 48 hours to determine if there is ANY water leak anywhere in the trailer fresh water system. And, thankfully NOT a drop of water anywhere! so, to my amazement, today when I d/c the city water, and go back to the 12V pump (knock on wood), works perfectly. turned each faucet/shower/toilet on and off briefly; all hot water sides 1st, then all cold. I know nothing, absolutely nothing "Col Klink) about the valving between city water inlet and 12V pump system - BUT is it possible that the vacuum leak could have been something to do w/the city water inlet valving. Maybe due to having used compressed air to winterize last fall? OR, as importantly is this just a fluke that will return to plague me at the least opportune time?

Goodspike · 04-02-2020, 04:19 PM

I vote for fluke. But just a guess.

Morich · 04-02-2020, 07:21 PM

Possible you have noted the right thing! As we hook to city water, we have a check valve thing just inside the place where we screw the hose. You can look at the hookup and see there is a little spring loaded "button" there.
You can push in (carefully) and see it move around.
So how about the idea that it got cocked kind of sideways and wasn't closing?
Not tried it but I might guess that would leave an air leak for the pump to blow out of and be hard to spot unless standing just right.
One of us should test that idea but I'm really, really, comfortable setting here!
Dangit! I might spill my coffee.

n9wdq · 04-05-2020, 06:30 PM

Why are you trying to use the water pump when hooked up to city water? City water has more than enough pressure to push the water, you do not need and should not use the water pump while hooked up. Some systems will "not allow" the pump to work while on city water

SML Brad · 04-06-2020, 07:07 AM

KG, just an FYI...I had to replace my pump because it wasn't pumping. After removing the old pump, I took the black plastic 'head' off to look it over. Did some you-tubing and figured out my check valve was stuck, so the pump was pumping against the stuck check valve. (The check valve is a little circular disc that appears to be a stamped piece of plastic, until you press hard on it and it moves in and out). So now I have a spare pump. This also appeared after winterizing it. I thought at the time a bunch of good pumps get thrown away when it might be this simple check valve. Glad you are fixed.

KGs2108DS · 04-10-2020, 07:36 AM

I noticed this thread was published in newsletter recently, and felt bad I hadn't posted resolution to this saga. 12VDC water pump working fine now; and, ever since having been connected to city water for 48hr. apparently (according to Winnebago dealer) there is some sort of check-ball/flap valve just inside city water intake. this prevents water being pumped out when 12V pump is being utilized. Best guess is that check valve was NOT completely closed/sealed, thus a slight vacuum leak preventing the 12V pump from shutting down completely. I did use compressed air to winterize last fall, and my compressor does NOT have an in-line filter. So, seems plausible that valve may not have sealed, and after 48hr of city water pressure/flow, this corrected itself. Simple fix, but lengthy ordeal - sounds about right, eh?

RVwithDogs · 04-10-2020, 08:36 AM

KG, your dealer is correct, you can see the check valve if you look directly into the city water inlet. If it is not seated and you are off city water and using your tank / pump the pump will continue to try and maintain pressure and water will weep or even flow out of the city water connection. By the way, never push that check valve with your finger while the system is pressurized by the pump, you will get a good cold shower and worse, you could cause the o-ring to un-seat then you would have to replace or repair the valve.

RVwithDogs · 04-10-2020, 12:44 PM

Sorry all, I had failed to see some previous great comments by others about the check valve being a cause. But this does bring up a good question . Once the valve fails is there any logical reason to fix / replace it ? I have seen other posts saying just cap the city water inlet when not in use. I was going to replace mine but soon discover that on a Navion (2014) it would be hard to get 2 hands and 2 wrenches behind the access panel ! I might be able to do it with shorter wrenches..