What's going on with my return pump?!?!

[jherrin215]

I bought a return pump from a fellow member and am very pleased with the transaction. It is a Iwaki 40rlt. Pump works great but every once in a while it will be just running along purring quietly then just start squealing so loud you can hear it on the 2nd story from the basement!! I finally throttled back the inlet side of the pump and got it to quit but was wondering if someone could give me some advice on what could be causing this and see if there were any solutinos besides reducing flow? Also as a side note, I tried throttling it down on the oultet side and though to seemed to not do it as often it still did it and still just as loud. It's been about an hour now so I think I'm good, was almost constant!

 

[The Punisher]

You shouldn't have to throttle the pump back to make it quite. There's got to be another issue going on here. Did you clean it really good before you started using it? That'd be the first thing I did to try and get it less noisy.

 

[jherrin215]

Yeah I know I shouldn't have to, that's why I'm posting on here. I broke it apart first thing and there was some brown crud in the bottom where the impeller slips into the part that covers the big magnet. I cleaned all this out but what I don't get is that it will be super quiet then just get crazy loud, then may quieten down again.

 

[jherrin215]

No one has any suggestions for this issue?

 

[Squint]

It could be a failing bearing, if the pump has bearings. If it has a cooling fan then it's more likely to have bearings.

 

[jherrin215]

I thought that but it doesn't sound like that. It is also sealed, you can't take the housing apart. I was going to replace the bearings before I put it into service but I can't. It really sounds like it's coming from the pump part, like it may be the ?delron? parts of the pump squealing.

 

[Squint]

I get some interesting results when I Google "Iwaki 40rlt bearings":

http://www.premiumaquatics.com/aquatic-supplies/IWMD-40RLT.html

Yesterday, the pump started making some incredibly horrible noises. First, checked to ensure that nothing was caught in the impeller. Next made sure that the fan wasn't hitting the casing. Next, I called Iwaki, who basically told me: "...tough luck. Sounds like a bearing. Our pumps usually last four to six years, I guess yours didn't, but it is out of warranty. You'll need to buy a new one."

I also see replacement parts and bearings available.

Even though the impeller may be magnetically-coupled, the motor and the cooling fan probably have their own bearings or bushings.

 

[jherrin215]

thanks for showing me that, I'll definitely keep that in mind if I decide to replace it

 

[Squint]

Chances are it's not the bushing/bearing for the impeller but one for the fan or motor. I'd start taking apart that half of the pump and feel for any rough bearings.

 

[jherrin215]

There are no bearings on the pump part of it. All that is there are two pieces of magnet covered in some type of plastic. The motor housing itself is sealed so there is no way that I can get into it to check/replace the bearings.

 

[jose7878]

I'm having the same issue with my 30 rlt . I called iwaki they told me to send it in to get repaired . So I asked how much would it cost to repair the motor . They said around $80 and will have to pay for shipping to them and then back to me . So it was cheaper for me to just replace the motor. If the motor is still under warranty iwaki gives it a 1 yr warranty so if it still under warranty you'ill just pay for shipping.

 

[Grubby]

Sounds to me like it is a POS. Just like the flippers on 31 and 32.

 

[tkeracer619]

Sounds like you were sold a bad pump. Has it been doing this from the start? If so the seller probably knew about it.

I would remove the whole pump section off the motor and let the motor free spin. A bad bearing is a bad bearing. Generally its not going to work fine for an hour then screech then stop. Once it starts screeching its going to lock up the motor in short order.

It could be a worn magnetic drive. It spins on the shaft fine but then decides to wobble. Is there any play in the magnet impeller assembly? Is there any wear on the ceramic shaft? Did you clean it so it looks like brand new on the inside?

Just like the flippers on 31 and 32.

I'm not sure what that means but if its political your better off leaving it out of any discussion on this board. Its against the rules.

 

[jherrin215]

I have removed the pump section and let the motor spin free, quiet as a mouse and smooth as silk. No noise whatsoever. The magnet feels good and solid on the shaft, not like it has any play. It will run for a long time quitely then let out the loudest high pitch squeal that is terrible. I did clean everything in the impeller and it all looks like new now. I don't understand how throttling back the inlet side could make it stop but the outlet side doesn't affect anything.
P.S. The previous message was nothing political, only a friendly inside joke.