Repairing the impeller motor of Dolphin S50

[Lacey]

This is a long shot, but I have to try.

After barely over 20 uses (1.5 seasons), our Dolphin S50 (for above ground pool) robot quit working. My husband took it apart only to find that it had been leaking water into the motor housing / chamber. Surprisingly we tested both the drive motor and the impeller motor and they both still work. Since water had been sitting in the "chamber", a few parts have corroded and broke. Specifically, the broken parts are the motor brush tension spring and the brush connecting wire (see attached pictures of the GOOD / intact side...the pictures are for reference of what we are in search of for replacement parts).

We are tried searching Maytronics website and they are kind enough to not list or sell any small parts...that we can find. Just a complete replacement of the entire motor assembly for $390!

If anyone can guide us as to where we might be able to find these small replacement parts, we would be very grateful, as I was hoping to get a few years out of this robot!

Thank you in advance for any help and advise!

 

[ctrav]

Not sure about where to get parts but doesn’t the unit come with a 2 year warranty?

 

[LeisureLuke]

Probably too late, but I was able to fix this problem by repairing the motor.
You opening the motor (just 2 screws on the bottom).
Find the bearing(s) that is bad.
Replace the bearings.
Good to go!

I made a video of mine. Hopefully it helps the next person with this problem!

 

[el duderino]

I just took my Pentair prowler 920 apart and this is what the motor looks like, which I’m assuming is not normal.
Anyone know a source for replacement motor without having to buy the entire assembly?

 

[peteip74]

I just took my Pentair prowler 920 apart and this is what the motor looks like, which I’m assuming is not normal.
Anyone know a source for replacement motor without having to buy the entire assembly?

Did you have any luck with that motor? I took mine apart and mine also looked like yours. Black dust/powder everywhere. I’m not sure where it’s coming from. My bearings all seem to be fine so I’m wondering if that black dust was somehow preventing the motor from working properly or if i need a new motor. Thx.

 

[wireform]

The black dust is the worn motor brushes. Get new brushes , clean up the rotor with ultra fine sand paper supported from behind with a very smooth block of sort just barely only to remove the black area and then blow out all dust with air compressor. Bearings should also be changed.

 

[peteip74]

Thanks for the Reply and info. I will definitely do that with mine.

 

[stone022]

Can you tell me how to find new brushes? I have it all apart, and I do believe the brushes failed but I haven't done this kind of work before.
Or, where can I buy a replacement Maytronics 5600024 motor? I'd pay some money for that instead.

 

[Trk3263]

I know this is an old post but I wanted to put my update here. My dolphin wouldn’t pass the initial in water test. It went forward then backwards and then stopped. I followed the directions in the video above and also found a ton of black dust (similar to brake dust) inside the motor. I blew it all out with my air compressor, verified the bearings still spin freely and put it back together. The dolphin is working again. The build date on my dolphin in 3/2020. I leave mine in the pool too much but run it almost everyday during pool season, we have a lot of trees. Hope this helps someone in the future since this site has helped me so much. Thank you

 

[JoyfulNoise]

I detailed a lot of this in my robot thread in my signature. Problem is, if your impeller motor is worn out, then more than likely your drive motor will seize up next. The drive motor is a lot harder to get at because it requires quite a bit of disassembly from the transmission it’s built on to. That disturbs the shaft seals which will then start to leak.

Not to sound snarky, but start saving your money because your robot is not long for this world and they are too costly to repair. Better to Somali buy new and toss the old out.

 

[Trk3263]

I detailed a lot of this in my robot thread in my signature. Problem is, if your impeller motor is worn out, then more than likely your drive motor will seize up next. The drive motor is a lot harder to get at because it requires quite a bit of disassembly from the transmission it’s built on to. That disturbs the shaft seals which will then start to leak.

Not to sound snarky, but start saving your money because your robot is not long for this world and they are too costly to repair. Better to Somali buy new and toss the old out.

Yea my clean out fix didn’t last long. It seemed to clean a full cycle but then when I tried to start it again it is back to failing the initial test and won’t run. I read through most of your long (lol) thread, it appears I will have to figure out something new and not leave it in the pool all the time like I did this one. However I didn’t notice much moisture just some corrosion. Definitely didn’t get as many years out of it as I feel like I should have.

 

[JoyfulNoise]

Yea my clean out fix didn’t last long. It seemed to clean a full cycle but then when I tried to start it again it is back to failing the initial test and won’t run. I read through most of your long (lol) thread, it appears I will have to figure out something new and not leave it in the pool all the time like I did this one. However I didn’t notice much moisture just some corrosion. Definitely didn’t get as many years out of it as I feel like I should have.

I don’t know how much leaving it in the pool affects it’s lifetime. Obviously water intrusion will lead to a catastrophic death. But it’s my opinion that the motor issues are simply a bad design/engineering choice and so getting 3-5 years of continuous use out of the motors they choose to install there is probably the best one can expect. This is why I went back to using a suction cleaner - I get decent performance out of it and it’s engineered to be more compatible with a pool environment using the energy that is already being spent on moving the water through the system. The simplicity of the internal components of a suction cleaner means that they can be rebuilt more easily and cheaply. Do they clean as well as an electric driven robot? No. Do I really need that level of cleaning perfection? No.

 

[Trk3263]

Any chance you remember what size brushes you ordered when you replaced the motor brushes? I got it running again with a little modifying and with how cheap those brushes are on McMaster-Carr I may try them out. My neighbor is in the lighting business and is going to talk with his supplier to see if he can’t get a few “samples” of those motors so we have them for spare, he has a dolphin too.

 

[wireform]

Following

 

[JoyfulNoise]

6mm brushes. But on some of the motors the channel that holds the brushes are 5mm x 6mm so you need to file them down. Make sure they travel smoothly in the holder or else they’ll get bound up and not make proper contact.