Has anyone pulled the pump out of their toilet?

06-07-2009, 08:09 AM

Has anyone pulled the pump from their toilet? Or I should back up here a bit....how much noise does the pump make? Thetford advertises that the recirculating toilet is quiet flushing, ours you can hear outside the TM. Best description is GGGRRRRR. It sounded like this when we picked up the TM at the dealer new.

Leslie & Nick · 06-07-2009, 09:13 AM

Quote:

Originally Posted by markndeb1970

Has anyone pulled the pump from their toilet? Or I should back up here a bit....how much noise does the pump make? Thetford advertises that the recirculating toilet is quiet flushing, ours you can hear outside the TM. Best description is GGGRRRRR. It sounded like this when we picked up the TM at the dealer new.

Everything is relative, but It's not that quiet!

You can certainly hear it from outside the trailer when the flush button is depressed. If you're getting good flow, there's probably nothing wrong with it. If pump goes bad, you'll know quick enough - you won't hear anything (also check fuse), or water swirl will be minimal.

Nick

06-07-2009, 11:19 AM

I agree...whoever said it is quiet must be hearing impaired. It is not at all quiet. I suspect as long as you have a good swirling flow that is as good as it gets. Dave (ShrimpBurrito) seems to be the Thetford expert on the list. If I recall correctly he wrote extensively about taking his apart, complete with dazzling color pictures! A search should find the thread...

06-08-2009, 06:28 PM

I thought so....thanks guys for the replies. I did email ShrimpBurrito and he said the same thing. I think it's because of having a permanent magnet motor to run the pump. They are noisy.

**ShrimpBurrito** · 06-08-2009, 06:50 PM

Just noticed this thread.....

I'm actually not sure it's the pump motor. The motor is easily accessible and removed -- simply pull the 2 screws to remove the cover on the back of the toilet, and it lifts right out (it may have 2 additional screws holding it in, I can't remember). Thus, if you ever have to replace the motor (assuming you can actually buy one from Thetford, that is), it would be about a 5-10 minute repair.

The motor sits in a socket that connects the motor shaft to the pump impeller shaft. When you lift the motor out of that socket, you can push the toilet flush button to actuate the pump and see how it sounds -- when I did that, it was much quieter than when you flush the toilet.

So simply by process of elimination, I can only think the racket comes from the pump impeller as well as the noise of the entire assembly being transmitted throughout the whole toilet.

The same thing happens with the water pump. Most people's fresh water pump probably sounds like something just short of an automatic weapon. But pull the pump off the wall and hold it in your hand, and it's no louder than a purring kitten.

Dave

Wavery · 06-08-2009, 08:05 PM

Yep!!!! I agree.....noisy....

06-13-2009, 07:57 AM

Thanks guys, if everybodys makes the same noise I don't think I'll worry about it, mabe just check the motor, but it does flow water well.
Thanks again!

**ShrimpBurrito** · 06-14-2009, 10:21 PM

Just came across this thread, where Al / Alrhall posted a picture of the motor in post #4.

Dave

Brittany Dogs · 06-23-2012, 01:01 PM

My Thetford pump, which is only a year old, started to sound like it "threw a bearing" and had a very different pump sound to it. It was like a mixture of the normal sound and a rattle sound. I figured that the pump motor had a premature failure. It was getting worse by the day.

So I started to take it apart and was very impressed how easy it was to get to the motor and remove it. Like ShrimpBurrito said, it comes apart easy and Thetford did a nice job providing a sealed linkage point so that the motor disconnects from the pump shaft easily.

The motor looked pretty good and when I ran it, the shaft did not vibrate at all. The motor probably has small sealed bearings or simply has a smooth shaft guide. I wanted to put a drop of oil on it but did not have any on hand. Then I realized that the dipstick to my truck would provide me with a tiny drop of synthetic oil to put on the motor shaft. I also put one drop on the coupling point of the pump shaft that goes to the inside of the stink pot.

When I replaced the motor I tested the motor and pump and it sounded normal without the extra rattle or bad bearing sound.

As I was about to replace the motor/switch housing, I then realized where the rattle and vibration sound might have been coming from. The fuse holder might have been just perfectly laying against the motor/switch housing and rattled as the motor vibrated things.

This is just a theory but in the mean time, the toilet now sounds normal and the fuse holder might have been the problem after all. There is now a paper towel loosely wrapped up inside the housing to pad the fuse holder. That way if I hear the bad bearing sound again, I can assume it was not the fuse holder.

**Bill** · 06-23-2012, 06:20 PM

Brittany Dogs -

Nice job of troubleshooting!

Let me add a quick note for others who might do the same. The shaft of the motor is connected to the shaft of the pump by a short (1-inch?) white nylon cylinder that just slips on and off the shafts. DO NOT LOSE THIS PIECE when you pull the pump motor out. It is apparently very hard to replace (per a previous thread ...).

Bill