6000 vibration/noise

[BobB]

Hi Roger,

One of my 6000 streams has started to vibrate sufficiently so that it can be heard while standing by my tank. The vibration is correlated with the speed of the pump, so when the 7094 kicks it up to 100%, you hear a corresponding increase in the vibration. There is no visible vibration; instead, I'm concerned about the noise the vibration produces, which is heard as a low rumbling, modulated by the speed the pump runs.
I read your previously advice (Roger's Advice ) to a fellow stream user. Last night, I disassembled and cleaned the drive unit and magnetic rotor; the only thing I didn't touch was the red "O" ring seal located at the very rear of the magnetic drive because it wasn't easily removed. Anyway, everything was cleaned and returned to the pump, however, the noise continues.
Would you be able to offer any other advice on solving the vibrational noise problem on my 6000?

Thanks!

 

[rvitko]

The red o ring seal should be undr neath a plate that is seperate from the magnet, often these pieces are fused together by lime deposits and this is the most common problem, this plate should be a track the magnet smoothly spins in.

 

[BobB]

Thanks Roger. What is the purpose of the red O ring anyway? Does it hold the rear bearing in place, while the magnetic rotor turns?

 

[rvitko]

It dampens vibration and provides a gap for water to flow through.

 

[BobB]

Hi Roger,

I took the O ring out from the vibrating stream last night. It was as clean as a whistle, as was the interior of the stream. When replaced, that particular stream still had a vibration, so I swapped the other stream's magnetic drive impellor assembly with the one making the vibration. Interestingly, the swap made little difference in the amount of vibration, so I guess its not due to the magnetic drive and impellor. Do you think that the vibration may be the result of a loose outer friction-fit bearing? What's the tolerance in the gap on that one; I'll check it with a microcaliper tonight. Thanks.

 

[rvitko]

I don't know what the tolerance is. One thing I am puzzled by though, you said you removed the o ring, now what about the plastic piece above the oring, was it stuck to the magnet? This piece should be free of the magnet. You might try prying out the collar and checking for debris underneath and then reinserting it rotated 180 degrees. It sounds to me like their is a problem with the water flow through the pump innards. The water suspends and lubricates the magnet. If the center hole is clogged in the magnet, the plate that is above the oring is stuck to the magnet, these are the most likely causes, secondary causes are the brakes being worn or the ring being out of alignment from sand or debris caught under neath it. I don't think enough wear could occur though to damage it. The only physical source of damage could be acids. Acids stronger than vinegar or very dilute muriatic- basically anything with a pH below 4 and high electronegativity will form hydrogen bonds with the plastic and change the tolarences. This is the only thing I know of that can cause enough change to alter the pump function.

 

[BobB]

You might be right about some bits of debris lodged in the center hole. When I originally took it apart the other day, there were small pieces of scale in the interior of the magnet drive, so... I'll check that tonight. The plate you refer to (the one above the o ring) is free, although it originally took a soak in vinegar to get it off. As far as I can see, the brakes look fine and overall I don't see any obvious signs of wear or scoring, so I'll bet there is some material I missed inside the center hole or collar.

Thanks for all the help!

Cheers,

BobB

 

[rvitko]

Try taking it apart so you can run a pipe cleaner or poker through the magnet hole.