Central Vac DIY Questions

[T-Rex]

Hi, I've been reading the content from you guys and thought I'd reach out with some specific questions.
I have an MD Silentmaster S44 purchased new in 2012. Motor died in 2019 and I replaced it with the Lamb 122525. It died again a few months ago.
I was thinking that these motors were not getting anywhere near the hours rated (we don't use it all that often but there is no way to tell actual hours). I was reading about replacing with other units, whether it be another MD, Drainvac, Cyclovac or Vacuflo (or even the OXO - oh no!).
So for S&Gs I decided to check the brushes and I've found one to have maybe 1/4" of carbon - and the other - gone! So I'm thinking maybe it was my fault all along not checking/replacing brushes but I didn't think I was even at 300-500 hours???

So, the rotor does look dirty but not really scored so I'm thinking now maybe I should just change motor out one for time for the latest 122685 for $150 (central vacuum online - is that place reputable? It is $75 less than MD direct). I'm also thinking about replacing the circuit board just so everything is new.

So my questions - about your recommendation... would you just refresh the parts for around $250 and just make sure in the future I check brushes every few years or would you recommend still replacing the whole thing?

The can is still in decent shape except for the foam is disintegrating. Is is possible to remove and replace that foam?

Thoughts/Opinions?

As fyi home is around 2900 sq ft and I have 3 inlets with longest around 50' of pipe. I was going to ask about bottom motor design, bags, etc. but that would not be necessary if I just refurb this unit... I live 10 minutes from Gator/Think Vacuums and was not impressed. Best option in store was a Drainvac for 1300 bucks.

Thanks!

 

[panasonicvac]

I'd say fix it up and give it one more try. Strange to hear this is the second time it's happened that quickly because it should last longer than that. But in all of honesty, this wouldn't be a SilentMaster or a single motor MD unit of my choosing. I was told once that CycloVac had a warranty for carbon brushes, either they used to do that or someone who told me that was misleading because they definitely don't cover it today. If a new unit is warranted, don't go for a DrainVac. That company and even Think Vacuums that they're sold from has been lacking lately.

 

[cheesewonton]

What exactly is wrong with the current motor? Brushes worn down? Bearing noise or bearings seized? Those motors can be rebuilt with new bearings and brushes and the commutator shined up with a stone for a lot less than buying a new one.

I would be tempted to investigate your central vacuum installation and plumbing to see if there is a restriction or some other factor that is causing excess wear on motors. Is the motor being adequately cooled? Are the bags becoming plugged starving the motor of airflow? It seems to me something is causing motors to fail and replacing the main unit may not solve the problem.

 

[T-Rex]

What exactly is wrong with the current motor? Brushes worn down? Bearing noise or bearings seized? Those motors can be rebuilt with new bearings and brushes and the commutator shined up with a stone for a lot less than buying a new one.

I would be tempted to investigate your central vacuum installation and plumbing to see if there is a restriction or some other factor that is causing excess wear on motors. Is the motor being adequately cooled? Are the bags becoming plugged starving the motor of airflow? It seems to me something is causing motors to fail and replacing the main unit may not solve the problem.

Thanks for the suggestions. It's been a few months but I just remember the motor quitting, maybe a smell but not sure if that was just the first one. I looked at the motor, shaft/fan spins freely. The commutator (I guess what the brushes rub against) is very dirt (guess carbon dust). Maybe some slight scratches but doesn't look gouged. Couldn't see how to get that out to clean it? I'd have to investigate the other options after it's running again. I can try to take some pics. One brush still had some carbon on it and other was completely gone. How long should those brushes last, ~800 hours? Is there a retrofit to add an hours meter to this unit?

Is there a big difference between the lamb motors 122525 and 122685? The 685 replaces the 525. Thanks...

Edit: Added pictures

 

[cheesewonton]

The commutator looks pretty bad. You could try putting new brushes in this motor, clean up the commutator and see what happens.

To clean up the commutator you would need what is called a commutator stone. The vac owner of the vac shop that has rebuilt motors for me cleans the commutator with the motor running by rubbing the end of the commutator stone on the commutator as the motor spins. It usually only takes a few seconds to make the commutator segments shine again. I have seen other techs take the motor apart, chuck the whole armature in a drill and use the drill to spin the armature while cleaning the commutator with a stone. I don't think you want to take it apart if the bearings are ok. Grainger sells commutator stones. A vac shop would have one they could maybe sell you. That is where I get mine. Try the easy and inexpensive things first.