Changing My Pump's Shaft Seal

[BigDave]

I've noticed some wetness under my pump (Hayward SP3400VSP) and have concluded that I need to replace the shaft seal. I called a local poolstore and should have the part this weekend. I plan to install it on Saturday and have a couple questions.

I've read about changing this seal online and feel confident that I can do the work. I read that one shouldn't touch the new seal when installing it. Can I wear Nitrile gloves to handle the seal? Should I clean it with something before installation? If so, what?

I'd also appreciate any other advice or tips on doing this job, I'm a little concerned that I might break my (expensive) pump.

[mas985]

It really isn't that hard just make sure you install it in the correct direction. Best thing is to observe the seal direction before you remove it. Avoid touching the surfaces of the seal and you shouldn't need to clean the seal surface unless you touch by accident. And if you do, then just use a little alcohol with a clean cloth.

Here is a video of someone replacing a seal on a Tristar which is the same as the EcoStar.

http://www.youtube.com/watch?v=C_x6h1D33rM

[nefretrameses]

I replaced the seal in my pump last year. After about 3 months it started leaking again. I thought maybe I used a lubricant that I shouldn't have, so I replaced it again. You guessed it, after a few months it's leaking! So I took it to a pool pump guy and told him the story. (How hard can it be after all? It's just a pump seal. I'm a handy guy). So he took it apart while I was standing there..... I put the seal in backwards - twice. Live & learn. Like Mark said: observe the seal direction before you remove it. Only use water based lubricants.

An other thing he told me was that main seal leaks must be fixed promptly. Water will cause rust to form on the motor housing and distort the housing. Then the motor is garbage.

[mas985]

You should never use any type of lubricant for the shaft seal. It must be installed without any foreign substance on the seal faces. Water vapor creates the actual seal.

For the o-rings, you should only use silicon based lube.

[BigDave]

Thanks!
Very much!
I replaced the seal today - it seems to be fine. (no smoke, pump runs, water flows).
I was able to remove the motor / seal plate / impeller / diffuser without removing the pool water plumbing - Yay!
I was able to remove the shaft seal without removing the seal plate from the motor - Yay!

I had a couple issues along the way:
1) There was no impeller screw. Not to be found any where ??? The shaft is threaded for it, it looks like it should be in the impeller but none!
2) The EcoStar motor has a flat on only one side of the shaft. I had to remove the fan to get a wrench on it. No standard size wrench would fit, I had to use an adjustable to keep the shaft from spinning.
3) The impeller was tight - I couldn't break it free by hand ( I have RA and am weaker than I used to be ). I had to add some persuasion with a strap wrench.
4) Found the back of the motor (near the fan)was not spinning free and making a chunking sound???? Found the back plate of the motor loose and not pressed into the motor housing proper. There are four holes on this piece that look like they should be for screws to hold the plate on - they were empty. I tapped the back plate in place with a rubber mallet and now the shaft spins freely. Are there supposed to be screws holding the back of this motor in place?

Thanks again
Dave

[nefretrameses]

I assume you inherited the pool and that someone has worked on the pump before. Motors of that size generally have 4 long thin "bolts" that hold the front and rear plates together. Each plate has a bearing for the armature shaft. My pool pump guy said that it is very difficult to remove them without breaking. He applied a lot of heat to the front plate at each bolt location while trying to remove the bolt. Eventually they all broke loose. I suspect the bolts are broken off in you motor. I'd be concerned if the plates are only held together by friction, although the motor has apparently run this way for some time. But the plates/bearings determine how "true"the shaft will turn. If it's not right and wobbles a little it'll eventually wear the seal again. I assume you close for winter. That would be a good time to check it out. You may need another seal if you take it apart. A motor or pump repair shop could probably get you the bolts

Not sure about the impeller screw. I watched the video that Mark posted. Looks like a "safety". Presumably the motor spins in a direction that will tend to tighten the impeller on the shaft. It may be worth getting one if you plan to take it apart again. Looks like it's reverse threaded and may only be available from the manufacturer. There are websites that supply OEM parts.

Interesting that the video recommends lubricant for assembly. There are also restrictions on lubricants for o rings on devices like a chlorine feeders.

www.ereplacementparts.com has a diagram, parts list and prices for your pump. I Googled "haywardsp3400vsp parts". You might want to replace the "impeller ring" while you're at it. This is a wear surface between the impeller and the diffuser.