# ADC FB1-4001A brush(es) troubleshooting



## GassedOut (9 mo ago)

I posted some pictures and description in my build thread regarding the state of the brushes in my new-to-me FB1-4001A motor. The motor is now out of the engine bay, and I was able to remove the end cap and get a better look at things. I'd appreciate any input on diagnosing its bench test failure (didn't spin under 12V power), aka, determining if I should go ahead and replace the brushes or if there's something else wrong that I need to dig into first.




























I've seen that brushes getting stuck in the holders is common from carbon build-up after sitting for a long time, but that doesn't explain why half of them are popped up like that, and several having chunks missing from them. Does that white residue around the brushes provide any hints as to what happened or why they're so stuck?

The brush I successfully removed measured within 0.1mm of the new spec length, so they can't have been run for long. I assume the 7-14-09 on the nameplate indicates a 2009 build date, which means it was pretty new when the half-finished conversion took place by the PO.










While blowing out dust and cobwebs, a couple small shards of what looks like foil/paper insulation fell out. I couldn't spot anything missing or torn, but sitting for that long, it wouldn't be a shocker if critters got in there.


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## kennybobby (Aug 10, 2012)

The debris needs to be blown out and removed for sure. The strips may have been something used to hold the brushes back during installation and was not removed properly.

The brushes are not making contact with the commutator so it won't run. The white residue is likely some oxide from the coating on the brush holders reacting to moisture over a long time. Remove the brushes and rub them lightly across some 400 grit to remove the white if it doesn't just blow off. Clean out the inside surface of the brush holders. The brushes should easily move in and out against the spring pressure.

Did you ever try to rotate the shaft by hand when it was assembled, was it locked up or free to turn?

It looks like there is an opening to insert the brushes after the end cap has been assembled, that would be easier than trying to hold the brushes back.


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## GassedOut (9 mo ago)

The shaft spun freely and smoothly in either direction with the transmission in neutral ... and didn't spin in gear, so I knew the coupler was engaged properly. That had me hopeful it would pass the 12V bench test, once I learned it's possible to test a higher voltage DC motor that way.

Yeah, the brush holders are accessible with the screen removed (with the end cap on), but the lower ones sit right above the engine mount crossmember, so getting in there isn't particularly easy. I would probably have to unbolt the driveshaft, loosen the tranny mount, and lift the motor several inches to do so with it in the engine bay. I wanted to remove it to get a better look at the motor-tranny coupler setup, though, so it was worth pulling the motor in this case.

Currently, all the brushes I've tried removing, other than the one that did come out, are totally seized up. They were crumbling under plier and channel lock pressure. Now that I can get to them from the bottom, I can hopefully apply more pressure. It doesn't look like any of them are going to be salvageable, judging from the number of chunks missing from them along the comm surface, so I guess I can be a bit extra forceful... It may be worth testing your theory of it being an oxide and see if it cleans up with medium grit sandpaper, though. Acetone should clean up the holders, but probably wouldn't be great for brush experimentation.

The bigger concern is why they're so seized, are the holders messed up, were the brushes ever seated properly, what caused half of them to pop up like that (they're not all in the same row, so it's not like they hit debris and were all affected in that path), and did something else go awry in the process?


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## remy_martian (Feb 4, 2019)

The only thing I can think of that could make a white film like that is that the motor was exposed to salt spray or somehow got exposed to chlorinated water (or rodent urine) and the brushes absorbed that moisture then cooked it off. Nothing else is corroded, though, apart from some modest white splashes of aluminum corrosion.

If it was my rebuild, I'd replace the brushes and springs. Be careful not to sand off that cadmium plating on the holders.


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## GassedOut (9 mo ago)

The truck is so rust-free, salt spray seems unlikely. Although, assuming it actually was running at some point after the conversion (seems unlikely, given the state of things), a single test drive could have gotten it salty before sitting for years. Rodents doing their business is plausible.

Some of the motor mount was done with stainless steel. I've never worked with stainless, but I know it's a lot more complicated with oxygen control and what not. I wonder if, a) that welding was done with the motor in place, and b) if the shielding gases used could have had any effect on the brushes?

Ooh, one other question I forgot to ask in the first post, are there any trusted brands and vendors for brushes? I found several options under the various part numbers (A91-112E, etc.):









BR22-120 - Brush Set, Advanced - Vintage Golf Cart Parts Inc.


Twin Lead Brush Set for 2003 & newer E-Z-GO with Advanced motor in models MPT 800 & 1000, also Express & Terrain models +++ 2006 and newer Club Car Villager and TransPorter models with IQ Plus system with 3.7hp motor +++ Also Motrec and Nordskog with Advanced motors with twin lead brushes.



www.vintagegolfcartparts.com












Brush, Single Wire Advance Dc (Set 4)






www.apexgolfcarts.com












Amazon.com : Performance Plus Carts EZGO Electric Single Wire Brush Set -4/Pkg : Sports & Outdoors


Amazon.com : Performance Plus Carts EZGO Electric Single Wire Brush Set -4/Pkg : Sports & Outdoors



www.amazon.com












EZGO Electric Single Wire Brush Set -4/Pkg


Performance Plus Carts carries a wide inventory of golf cart accessories, custom parts & golf carts for sales. We have parts & accessories for EZGO, Yamaha, Club Car golf carts & other popular brands. Shop online or visit our store in Central Florida for golf cart repairs & sales.




www.performancepluscarts.com












E-Z-GO Advanced DC Brush (Fits 1997-Up)


This golf cart part is a E-Z-GO 2-Wire Advance DC Brush (Fits 1997-Up) and works with E-Z-GO vehicles.




www.cartpros.com






E-Z-GO 2-Wire Advance DC Brush (Years 1997-Up)







ADVANCED DC MOTORS A91-112E BRUSH - MOTOR. 1 Day Shipping for AVA91-112E to 92% of the USA on most ADVANCED DC MOTORS Parts from Trupar America! Forklift Parts, Sweeper Scrubber Parts, Aerial Lift Parts, golf cart parts, earth moving equipment parts.


ADVANCED DC MOTORS A91-112E BRUSH - MOTOR. Shipping 1 DAY GROUND for AVA91-112E to 92% of the continental USA on most Parts! 800-222-9606 Trupar America Est. 1979 Parts for All Models New and Old. Free Shipping on qualified orders!



www.truparforkliftparts.com






https://trupar.com/p/advanced-dc-motor-motor-brush-single-a91-112e




https://www.dcmotorparts.com/advanced-dc-motors.html







Newton's Electric







www.newtonselectric.com












Advanced Motors & Drives Brush







www.jnelectric.com












BRUSH, TWO WIRE ADVANCE DC (SET 4)


Brush set, single wire for Advanced DC motors. For E-Z-GO electric 1997-up. 1-5/16"x31/32"x5/8" Manufacturer & Part # A89-012A AD , A89-012E AD , A91-112A AD , A91-112E AD , 547 BU , 73120G39 EZ , 73120-G39 EZ , 6-049A FP




parts.golfcarsofdallas.com





There's not a huge range in price, so if some are better than others, that would be worthwhile.


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## remy_martian (Feb 4, 2019)

Shielding gases are either CO2 or Argon - neither would affect the carbon brush chemistry.

It looks like the brushes were somehow soaked (maybe WD40 if they were sticking, lol), then the stuff got cooked off.


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## GassedOut (9 mo ago)

remy_martian said:


> Shielding gases are either CO2 or Argon - neither would affect the carbon brush chemistry.


Mild steel and aluminum are, but SS is a tri-mix that escapes me off-hand... Probably still not the answer, just a possible explanation that came to mind.



> It looks like the brushes were somehow soaked (maybe WD40 if they were sticking, lol), then the stuff got cooked off.


That could well be. WD40 ... 1,001 uses, all of them the wrong application!


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## remy_martian (Feb 4, 2019)

I think trimix has helium...


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## kennybobby (Aug 10, 2012)

You could try vinegar to possibly dissolve the oxide, use acetone at reassembly at the end to dry everything out. i might use some wooden dowels or blocks against the brushes as you punch them out with a hammer. If the old ones won't be salvaged then it doesn't matter so much. 

i would imagine that the coating is gone on the inside surfaces of the brush holder. Not sure what would be a good repair solution for that.


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## GassedOut (9 mo ago)

I spent a couple hours on Monday hammering the brushes out and cleaning up the holders. To get an idea of how seized they were, it took a comparable amount of force to driving in a substantial nail.

Acetone had no discernible effect on the corrosion and carbon accumulation on the holders, and I'm not sure carb cleaner fared any better. It took a lot of tedious scraping with an x-acto to smooth them out enough for the brushes to move relatively easily. Once I had them to that point, working the brushes in and out was actually the best remedy for the remaining crud. They all slide freely now.










The state of the brushes once removed was not good... But, it got me thinking, they're all intact and probably good enough to re-run the bench test to verify condition of the motor before ordering new brushes.




























And finally, cleaned up pretty good:










As kennybobby predicted, the surface doesn't look so hot. In searching fruitlessly for whether lubes (white lithium?) can be used on brush holders, I ran across this thread:









Best Way to Clean Motor Brushes and Commutator?


In my continuing struggle to get a Rabbit conversion back on the road, I've run into a problem. Motor spun up fine in neutral but on the first test drive, after a block or so, I had audible sparking at the brushes and the motor would refuse to spin up if it stopped in certain positions...




www.diyelectriccar.com





Deja vu... I'm thinking brush removal should be listed as preventative maintenance for DC motors if they'll be sitting for a while!

All I could find was stuff saying to not use lube between the brushes and commutator. I can't see any harm in lubing the holders lightly, unless it were to run down and make its way onto the comm...which I guess is bound to happen as the brushes wear down and pull the lubed portion closer. I also struck out in finding replacement holders. It looks like the whole assembly would need to be replaced, as the holders appear to be riveted to that inner ring with those dimpled brass heads.

But, to the more important point, I put the sketchy brushes back in and hooked it up to 12V power ... and it runs! The brushes sounded a bit clunky, not surprising with those chunks blown out, but it ran smooth and quiet.


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## remy_martian (Feb 4, 2019)

Graphite might work as a "lubricant", but I have no idea what it would do under arcing or high current conditions.

I would try to maybe polish or lap the copper brush holder. Super smooth might help.


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## GassedOut (9 mo ago)

remy_martian said:


> Graphite might work as a "lubricant, but I have no idea what it would do under arcing or high current conditions.


One of the things I read, as far as not lubing the brush faces themselves, is that graphite is the primary component so they're self-lubricating. As such, I could see an argument being made for either: a) don't bother lubing them with graphite because it's redundant, or b) it couldn't hurt to lube them with graphite, because the comm wouldn't see it as any different.



> I would try to maybe polish or lap the copper brush holder. Super smooth might help.


Yeah, I'll try getting them smoother still before putting new brushes in. Access isn't the easiest, but maybe additional disassembly of the end cap will help.


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## remy_martian (Feb 4, 2019)

I was referring to lubing the brush holder walls to get rid of the sticking and get a consistent force against the commutator.

I would not mess with lubing the commutator and would let the brushes break in on them dry.


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## GassedOut (9 mo ago)

remy_martian said:


> I was referring to lubing the brush holder walls to get rid of the sticking and get a consistent force against the commutator.
> 
> I would not mess with lubing the commutator and would let the brushes break in on them dry.


Right. I was applying the logic of the brush face argument for not lubing, to also being redundant as far as lubing the holders with graphite.


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## kennybobby (Aug 10, 2012)

Did you happen to try Vinegar to dissolve the white deposits?

Is the brush holder made of steel (magnetic) or is it copper?

If you decide to try cleaning some more, Maybe try some Brasso or other brand metal polish on the inside surfaces to remove the yellow spots. Wrap a cloth on a wooden dowel and scrub that muther out. It may work just fine for years as is, just depends upon your OCD level.

The brushes look ok and will work fine once they seat in to a fresh surface; Did all the white residue come off the sides?


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## GassedOut (9 mo ago)

I did use vinegar on the brushes after scraping the deposits down a bit, and it did seem to help with the white residue. I also tried it on the holders and it had no effect, as far as I could tell. But, it might be worth another round of that now that all the buildup is removed.

The holders appear to be copper, but I hadn't thought to check if they're magnetic... I checked just now and they're non-magnetic.

I have Mother's aluminum polish; which looks like it might work. I'm not familiar with Brasso, but the name implies it's more suitable to copper and brass.

You think the brushes are still usable, huh? That's a pleasant surprise! Oh yeah, I did take one more photo of them after cleaning them up:


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## piotrsko (Dec 9, 2007)

Graphite is porous so they will now be acidic as heck. Bad juju in motors. I suspect they got wet and the white powder is ash remains of arc burning because they were too loose in the holders. Should be a nice slip fit like gapping a set of points in the olden days, but no wobble anywhere, perhaps about 1lb of drag force to move them in the holders. If they are bouncing, perhaps a very light stoning of the comm when you get new brushes then a long seating run


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## kennybobby (Aug 10, 2012)

Make a paste of baking soda and water to dip or brush on the brushes to neutralize any acid, then wash with soap and water, then rinse with alcohol or acetone for remove any water or oil residue.

Could the brush holder be made of brass? It appears to be stamped plates held together with pressed joints, no fasteners. Just wondering what metal would produce white oxide like that.


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## remy_martian (Feb 4, 2019)

The prior owner may have used aluminum foil shims - aluminum oxide is white. Salt water will leave a white residue, as will chlorinated tap water. 

It's merely a curiosity at this point -- the main thing is getting the brush holders restored and I think polishing them is the right move. 

At first I thought the holders were cad plated steel, but copper for cooling would make sense. Conductivity should be through the copper braid of the brush in any case.


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## GassedOut (9 mo ago)

All of a sudden, this thread may have to get stickied for DC brush info. 



piotrsko said:


> Graphite is porous so they will now be acidic as heck. Bad juju in motors. I suspect they got wet and the white powder is ash remains of arc burning because they were too loose in the holders.


That theory would explain the blown-out chunks on the faces of the brushes. My lingering question was, were they afflicted by arcing, and if so, is that a sign of any other issues on a motor that appears to have been fairly new and not run long? If the issue was isolated to the brushes themselves, that eases any such concerns.



> Should be a nice slip fit like gapping a set of points in the olden days, but no wobble anywhere, perhaps about 1lb of drag force to move them in the holders. If they are bouncing, perhaps a very light stoning of the comm when you get new brushes then a long seating run


The way I've got them now, with more cleaning/polishing still to be done, they require very slight pressure to move and don't have any play in the holders.



kennybobby said:


> Make a paste of baking soda and water to dip or brush on the brushes to neutralize any acid, then wash with soap and water, then rinse with alcohol or acetone for remove any water or oil residue.


Will do, thanks.



> Could the brush holder be made of brass? It appears to be stamped plates held together with pressed joints, no fasteners. Just wondering what metal would produce white oxide like that.


Other than brass usually being darker, I'm not sure how to tell it apart from copper...? The holders are definitely darker than the copper lugs that the brushes bolt to, so I could buy them being brass. Or maybe some sort of plating over copper. The areas I cleaned up look more like copper to my untrained eye.



remy_martian said:


> The prior owner may have used aluminum foil shims - aluminum oxide is white. Salt water will leave a white residue, as will chlorinated tap water.


That could explain the two pieces of foil looking shards that left the case when I blew it out with compressed air.



> At first I thought the holders were cad plated steel, but copper for cooling would make sense. Conductivity should be through the copper braid of the brush in any case.


That raises an interesting question of what isolates the brush conductivity from the case? I'll have to take a closer look at that when I remove the end cap for more holder cleaning. Copper braids conduct through the brushes, so wouldn't the brush contact with the holders also conduct? Or does the slight air space act as enough of an insulator?


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## kennybobby (Aug 10, 2012)

Isolation is by the black phenolic ring held to the case with 4 screws. You could remove that ring along with the brush holders to get it out where you can scrub it down on the bench. Steel wool or abrasive scrubby pad would get after the stains, followed by metal polish.

The copper buss bar has a reddish tint but the holders appear yellow to me.


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## remy_martian (Feb 4, 2019)

The brush holders should be fastened to a phenolic or otherwise insulating material

Edit: can't delete posts so leaving up what was already said by KB


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## piotrsko (Dec 9, 2007)

Cant say it often enough.

Brass isn't as conductive or cheap as pure copper.

The only issue I have with abrasive polishing is getting all the residue off since it's still abrasive as heck. Polished a set of shovelhead rocker covers nice and bright, once. Cleaned the bejesus out of them including trichlor soak and a dishwasher cycle. Still rapidly wore out a new set of valve guides in about 5,000 miles. Otoh, you're going to get road dirt particles in the motor anyways.


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## GassedOut (9 mo ago)

Cleaning off the grit thoroughly is one of the big gotchas of lapping valves, as well. Having a better idea of how to remove the holder assembly now, I may take it all apart for easier work space and cleanup. At least in the case of brush holders, they're up against a wear item (brushes), so some polishing abrasive left behind will primarily target that as the weakest link.


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## kennybobby (Aug 10, 2012)

The brush holders don't need to carry any current, that is all done thru the copper buss bar connection to the brush thru the copper leads. So the conductivity of the holder material doesn't matter.

The brush holders _do_ need to provide a rigid structure to fix and hold the position of the brushes with respect to the commutator. Which metal would have better material properties for this task, brass or copper? If they were made of copper then what is the yellow coating?


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## remy_martian (Feb 4, 2019)

Rodent juice

I agree that copper is too soft, but it has the pre-greened oxidized look of copper. I first thought it was cadmium plated steel.

In a totally non-functional area of the holder, a light hit with a file would immediately give up its secrets.


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## GassedOut (9 mo ago)

More than anyone wanted to know about differentiating copper from brass, other than maybe budding metallurgists:









How to Tell Brass from Copper: 9 Steps (with Pictures) - wikiHow


Copper is a single metal, so every copper object has roughly the same properties. Brass, on the other hand, is an alloy of copper, zinc, and often other metals as well. The hundreds of different combinations means there is no single,...




www.wikihow.com





I found a 1980 penny, which should be a good scratch test.


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## GassedOut (9 mo ago)

It appears the holders are solid brass. The copper penny test didn't scratch it at all. The yellow "spots" were actually the areas that the carbon buildup had been best cleaned down to the surface. I still have a ways to go, but I've made good progress getting them uniformly smooth and shiny, using a vinegar and salt solution ... lots of alternating rubbing and scraping.


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## piotrsko (Dec 9, 2007)

The copper penny test only indicates the *hardness* of the holders is greater than the penny hardness and should have marked the penny but does not guarantee they are brass. Testing using a series of different tests will generally lead to a trend indicating what the holders may be, but the manufacturer specifications is the only real solution other than getting a new, unused part and testing that.


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## GassedOut (9 mo ago)

piotrsko said:


> The copper penny test only indicates the *hardness* of the holders is greater than the penny hardness and should have marked the penny but does not guarantee they are brass.


Understood. Thus the usage of, "appears."  They're not copper, but they could still be something other than the various alloys of brass.


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## GassedOut (9 mo ago)

GassedOut said:


> The brush I successfully removed measured within 0.1mm of the new spec length, so they can't have been run for long. I assume the 7-14-09 on the nameplate indicates a 2009 build date, which means it was pretty new when the half-finished conversion took place by the PO.


I just noticed in the ADC schematic, "namelabel stamped with U.L. ID. NO. AU2500 & current date in rating box," so that confirms my hunch:



http://www.evamerica.com/fb14001aoreve1.pdf



BTW, does anyone know if ADC went out of business and when? I haven't found anything recent for them.


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## GassedOut (9 mo ago)

Here's the current state of the brush holders. I don't know what to make of the reddish color revealing itself... Brass-coated copper wouldn't make any sense, would it?



















(The holder's orientation probably doesn't matter, but I saw that blue paint smudge and figured I might as well mark it and the corresponding spot on the end cap with painter's tape.)


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## remy_martian (Feb 4, 2019)

Probably the acid and salt attacking the metal...

The main thing, imo, is to polish it mirror smooth so the brushes don't stick.


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## ekthor (Sep 1, 2012)

GassedOut said:


> I just noticed in the ADC schematic, "namelabel stamped with U.L. ID. NO. AU2500 & current date in rating box," so that confirms my hunch:
> 
> 
> 
> ...


AMD, formerly ADC stopped DC Series production 10+ years ago. Warfield/NetGain took their designs to make and improve the WarP line of motors, both were the most popular motors in EV conversions for 2+ decades, they are all nearly extinct this days, a very bad decision considering that ICE motors are very inefficient and will be around another decade or so. DC are not above the 90% efficiency as compared to AC/SynR Motors but they are good. A shame. I always use RPM and temp sensors on DC Series Motors, so they can last many, many years of service.


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## piotrsko (Dec 9, 2007)

Other main issue of brushed DC: since most of the major manufacturers built series DC, there is no good method of generating regen except for removing the series connection and making it controllable which negates some of the series wound advantages.


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