Pool pump and impeller question...thoughts?

CajunGuy

Well-known member
Apr 6, 2016
308
Louisiana
My pool pump (Pentair Whisperflo) wasn't turning on (would only make a humming noise when I flipped it on), checked the capacitor at Grainger and they said it was good. Went back and pulled the motor from the pump. When I removed it, the seal plate, diffuser, and impeller were still attached. The diffuser looks fine, removed it to view the impeller. I tried turning the impeller/shaft and it was a bit hard to turn, once I removed the impeller the shaft turned MUCH easier. So I tightened the impeller back on and again it was difficult to spin. The impeller seats into the seal plate and on the inside it looks like it has some type of spring in the middle that the impeller sits on/in. Could that spring or something in the seal plate be causing my impeller/shafts not to turn?
 

crudsrus

LifeTime Supporter
May 16, 2010
72
Yuma AZ
The "spring" is part of the pump seal. One part mounts to rear of impeller and mates to the spring half. Ensure the seal on back of impeller is clean and not damage d. Clean with a clean rag " ceramic side" The impeller bolt is reverse threads.

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JamesW

TFP Expert
Mar 2, 2011
13,325
There’s a black rub mark to the right. I suspect that the impeller is rubbing there. This is usually due to the motor not sitting flush with the seal plate. This is usually because one of the grommets that receive the bolts that hold the motor to the seal plate has come loose.
 

CajunGuy

Well-known member
Apr 6, 2016
308
Louisiana
Rear view of impeller. Not sure what the seal is supposed to look like.

- - - Updated - - -

Rear side of seal plate that motor attaches to. Looks pretty old with a good bit of corrosion around the screw areas. Again, not sure what the seal should look like.
 

Attachments

JamesW

TFP Expert
Mar 2, 2011
13,325
That’s the ceramic part of the seal. It’s bad. You’re going to need to replace that.

The other part of the seal is also bad, you’re going to need to separate the motor and seal plate. Most likely, the bolts won’t come out without taking the grommets with them.

The seal plate is bad. You might want to consider replacing the pump at this point.
 

CajunGuy

Well-known member
Apr 6, 2016
308
Louisiana
There’s a black rub mark to the right. I suspect that the impeller is rubbing there. This is usually due to the motor not sitting flush with the seal plate. This is usually because one of the grommets that receive the bolts that hold the motor to the seal plate has come loose.
JamesW, take a look at the areas around the screw holes, the bottom two are definitely cracked, and the top two have a lot of buildup corrosion around it. You think maybe just the seal plate needs to be changed out? It looks to be in pretty bad shape. What about the shafts seal?

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JamesW, I've got the seal plate removed. Grommets look terrible. Bottom two are cracked around the grommets. Lots of corrosion. Shafts spends pretty easy once impeller is taken off. So where do I go from here?
 

JamesW

TFP Expert
Mar 2, 2011
13,325
Seal plate is bad and the shaft seal is also bad.

You can do a new seal plate and seal, but I would consider replacing the pump with something more efficient. That thing is an energy monster.
 

CajunGuy

Well-known member
Apr 6, 2016
308
Louisiana
Seal plate is bad and the shaft seal is also bad.
Anything else I should look for or check to see if something else needs to be replaced? Does the seal plate usually come with the shaft seal included? Is my impeller still good to use? It doesn't look cracked or anything from a visual inspection.
 

JamesW

TFP Expert
Mar 2, 2011
13,325
The seal plate does not come with the seal. A good seal is part number PS-3865. The impeller looks like it has some flaring from heat, but I think that it’s still usable. The old ceramic part of the seal with the rubber boot can be difficult to remove from the impeller.
 

CajunGuy

Well-known member
Apr 6, 2016
308
Louisiana
Seal plate is bad and the shaft seal is also bad.

You can do a new seal plate and seal, but I would consider replacing the pump with something more efficient. That thing is an energy monster.
I was told that my plumbing had too many "elbows" for a dual or VS pump to run on the lower setting(s), basically it wouldn't have enough flow.
 

CajunGuy

Well-known member
Apr 6, 2016
308
Louisiana
So the cheapest option so far would be a new seal plate ($55) and a new shaft seal ($11) and use my old impeller and diffuser.

Is the shaft seal in the gokit32salt the same as the PS-3865 shaft seal? Or is the PS-3865 a more "heavy duty" shaft seal?

Does the seal plate come with the seal gasket? Should I maybe just buy the gokit32salt and that way I could replace the seal and diffuser gaskets too?
 

CajunGuy

Well-known member
Apr 6, 2016
308
Louisiana
Ok one last thing, how tight should I put the impeller on? Hand tight? It also has a screw on the front side (diffuser side), how tight should that screw be on there?
 

crudsrus

LifeTime Supporter
May 16, 2010
72
Yuma AZ
Seal plate and the go kit should have everything you need.
Impeller should be installed snug , remember screw is reverse thread.
Seal was leaking from rear of motor which likely caused your problems.
Plumbing elbows are fine for a variable speed pump.....

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CJadamec

TFP Expert
Apr 29, 2016
2,253
Quaker Hill, CT
Who ever told you there were too many elbows for a VS pump to work doesn't understand plumbing very well. You would be fine with an intelliflo or superflo main pump for the pool. It would save you a ton on electricity too.
 

CajunGuy

Well-known member
Apr 6, 2016
308
Louisiana
Thanks again you guys for all the help and advice so far! I have another question. I noticed the shaft has a little bit of rust around the portion where the spring part of the seal was (in the seal plate). Would it be OK or wise to clean that rust off with some sand paper or wire brush? Also, should I put a thin coat of Aladdin lubricant on the shaft for rust prevention...or no? Am I suppose to lubricate all 3 seals...the shaft seal, seal gasket, and diffuser gasket?

Also, because I like to know how things work and the cause of the problem...the reason the shaft/impeller weren't spinning was because the impeller was getting stuck against the seal plate because the housing around the grommets were cracked causing a bad fit (not flush) and water was getting through the shaft seal too?
 

CJadamec

TFP Expert
Apr 29, 2016
2,253
Quaker Hill, CT
Absolutely no lubrication should be put onto a mechanical shaft seal. Not even onto the rubber cup for the ceramic piece or the rubber that is on the shaft. The face where the ceramic (white disk) and carbon (black disk) should be kept as clean as possible. You shouldn't even touch them with bare fingers if you can help it.

The bad seal could cause the motor to not spin well. When you put the impeller on it compresses the spring in the seal pushing the carbon and ceramic together. Normally those faces spin against each other and the carbon face will slowly wear away until the seal fails. Which under normal operation will take a very very long time. Things like running the pump dry, cavitation from suction air leaks, and overheating the pump will drastically reduce the life of a seal.
 

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