Water pump issue on 5th wheel.

[Bansh88]

2003 Rampage. All of a sudden water pump hums but doesn't pump water. Any ideas? Anything to troubleshoot? Or just swap it out. Look like a very easy replacement but want to make sure there's not an easy fix.
Noticed it stopped working after a long drive to Montana. Worked fine before. Issue began before any significant freeze.

 

[LegitDuner]

Is it one of those on-demand Shurflo-type pumps? I would whack the pump head with a rubber mallet and see if the diaphragms are stuck. I assume you already checked the feed line to make sure that it's getting primed. They make a rebuild kit for the pump part if the motor is fine, which it sounds like it is.

Edit-Just reread your post and you say the motor is humming. I assumed it was spinning but maybe it's humming because the motor isn't spinning. Whack it with a mallet... If it works I would plan on getting a new pump motor.

 

[Bansh88]

 

[Bansh88]

I assume you already checked the feed line to make sure that it's getting primed.

You assume too much. Is it possible the tank was drained so low it needs to be primed? I'll have to see how to do that

 

[honEXduner]

You assume too much. Is it possible the tank was drained so low it needs to be primed? I'll have to see how to do that

Most tanks have ports going to the water pump fairly low on the tank but it could happen. Would think most all of those are self priming by design since they are almost always above the tank level in a trailer application. Make sure if you have any inlet screens that they are clear. Have had one get gunked up with algae crap and cause issues before. Concur with the mallet approach to start.

 

[megadesertdiesel]

sounds like it lost prime. Could be a loose connection letting in air or cracked line. Could also be a broken impeller inside the pump no longer connected to the motor. Either way pull the motor and see if it has any obstructions and temporarily hook up some hose and a bucket of water.

Pumps are cheap and a small accumulator tank helps the pump not run all the time.

 

[MWB]

Pull it apart and take a look at it. My old one after a few years got a little piece of plastic stuck in it and was doing the same thing. it's just a couple screws. Pull it apart make sure the motor spins, and that the impeller turns freely and reassemble. It will take less time than reading all the comments.