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.

[BigDave]

Thanks, I kinda wish I could blame it on a previous owner. I bought it "new" and installed it my self at the beginning of last summer. I suspect now that this pump was in someone else's hands before I got it. I'm pretty peeved .

The bearing in the back plate has been noisy since day one and required wiggling it to "just the right place" to get it to run quiet. I now know what that was. It started up and ran quiet after I set the back plate in place.

I haven't, yet, been able to find a parts list for the motor to confirm the screws are missing. When I had it on the bench, I couldn't see threads or broken screws through the little holes but I could have easily missed them. I could see that the holes do line up between the windings which tells me that something should be there.

I agree that the video's a little off message regarding lubricant but he does wipe the sealing surfaces down with alcohol after using the vegetable oil. I didn't need any assembly lube to get the ceramic disk and rubber cup set in place. You definitely don't want any lube on the shaft or inside the impeller side of the seal as it needs to grip the shaft and spin with it.

[mas985]

The vegetable oil he shows is only used to help seat the seal and it should only be used on the rubber piece. But I have never had to use a lubricant on the rubber part to seat the seal. I have seen other seal videos recommending other types of lubricant for the rubber so I think it is a SOP in the industry. Another trick to keep the seal clean is to lube the housing instead of the rubber.

Anyway as to your issues:

1) The impeller will normally stay on by itself without an impeller screw but the parts diagram shows one so it should have one. Parts

2&3) Sometimes that can be a real PITA but a strap wrench is the right tool for the job.

4) There should be 4 screws that hold on the rear of motor to the motor housing. If you pull on the back of the motor, does it separate from the housing? I would try to find some screws to fit.

[BigDave]

Thanks! Much appreciated.
I will order an impeller screw if I ever have to open the pump again (hopefully never).
Since I can't find parts for this motor, I wouldn't where to start to find such screws. Perhaps I'll ask Hayward to send me a set when I complain about the missing impeller screw.

[nefretrameses]

The threads that these screws would go in to would be in the plate all the way at the other end of the motor housing - the one that bolts to the pump housing. You'd have to take the pump apart again and remove the front motor plate in order to see the threads. They would be on the inside face of the plate. The screws or bolts should be almost as long as the motor itself. You could probably Google the motor by its part number and get a parts list that would include the screws. Also try a pool pump motor replacement website. Many of them will have a "motor finder" where you can cross reference your motor to a generic number. You could then search for parts for that. If they're just missing and you can get them, you may be able to just install them. If somebody broke them off, you'll have to take it all apart to get to that front plate and try to extract the broken off pieces. I would expect that to be a significant challenge. I guess you could always replace the plate. At some point a new motor would be more economical.