Brushes

Status
Not open for further replies.
While there are brushes in there,by the time they wear out you need a new unit anyway.Remember,alternators have smooth slip rings,not segmented/rough commutators like generators....so they wear a lot slower.
 
Originally Posted By: OneEyeJack
Does anyone replace the brushes on their alternator?

What make, model, and year of car?

Some alternators -- Denso, for instance -- allow you to change the brushes easily; I've done it a few times. Other than routine brush replacement, Denso alternators will run forever if cared for.
 
Alternator parts are still available, but I needed some on my Jeep about a year ago, and even the local indy parts store laughed at me. He said they hadn't sold a starter or alternator brush set in years. Beings I needed the alternator immediately, I bought a reman. Your best bet for getting individual parts is RockAuto, but waiting a couple of days for parts isn't worth it if the alternator is needed immediately. There is still a local rebuilder shop near me that has parts for even the odd-ball stuff, but even getting the grumpy guy to look the numbers is a real challenge.
 
In an alternator the brushes only carry the load of the excite circuit, not the output of the alternator. This was an advantage when cars moved from a generator to alternator in the mid 1960s.

A rebuild shop is the best place for new brushes. I do not replace them until I have a alternator problem. Sometimes the surface the brushes rub against needs to be turned on a metal lathe.
 
Originally Posted By: Donald
A rebuild shop is the best place for new brushes

Except that you get the brushes loose and need to solder them to the old brush holder. How many people know how to solder? and how many have an iron capable of the sort of heat required? Plus you may need to sand the brushes to the diameter of the slip rings.

Denso replacement alternator brushes are contained within a special holder, which is what makes it easy to change them: remove the rear cover (2 screws), remove the holder (2 screws), reinstall, done. No soldering needed. The brush holder assembly costs about $25.
 
Alternator brushes and assemblies can also be found on web sites like Amazon and others. No soldering required. My 4 cyl Accord brushes can be changed without even pulling the alternator.

http://www.amazon.com/s/ref=nb_sb_noss?u...nator%20burshes

Last alternator brush and bearing change I did was on my "classic" 69 Nova since I wanted to keep the OEM alternator working.
 
Last edited:
Yes, you can replace the brushes BUT in my experience you can usually only replace the brushes once or maybe twice before the slip rings need to be replaced. By the time you wear out two or three sets of brushes, the slip rings will be worn (or warped). By that time - if you haven't blown the diodes or regulator - you've probably worn out the bearings anyway.
 
Originally Posted By: OneEyeJack
Does anyone replace the brushes on their alternator?


I've done it a few times. Finding a source of the parts is trickier than doing the job. They used to sell 'alternator kits' in blister packs containing brushes, diodes, and bearings. But I haven't seen those in parts stores in almost 20 years. A local rebuilder might sell them to you.

Truthfully, you can replace the brushes once and by the time they need it again the slip-rings they ride on need to be replaced, which is a complete rotor rebuild.

I still prefer rebuilding alternators this way rather than the mass process that mixes and matches parts and runs everything through the vibrating polisher and tends to ruin all the tolerances. That's why I use a local rebuilder most of the time even if I don't do the work myself.
 
Originally Posted By: Tegger
Originally Posted By: Donald
A rebuild shop is the best place for new brushes

Except that you get the brushes loose and need to solder them to the old brush holder. How many people know how to solder?


Not in any alternators I've ever opened up. The original autmobile alternator (1960 Chrysler) had brush modules that screwed in place and came pre-assembled with the brushes soldered to the copper braid that attached to the screw-down tab that held the module in the case. On those you can swap brushes in 5 minutes without removing the alternator from the car or even loosening the belt. The vast majority of alternators built since follow that pattern of a brush module with all the soldering pre-done, including Delco, Denso, Bosch, and others.
 
While there may well be some, no Ford alt I've rebuilt ever had soldered brushes, and yes I know how to solder...
 
I must be lost in space. My 84 Honda Civic (I'm the original owner) has a bit over 400k miles and I've replaced the brushes twice, and the alternator is working like new. Both times the brushes had about 25% left compared to the replacement brushes. I was just wondering if alternators are replaced just because the brushes were worn out.
 
Originally Posted By: OneEyeJack
I must be lost in space. My 84 Honda Civic (I'm the original owner) has a bit over 400k miles and I've replaced the brushes twice, and the alternator is working like new. Both times the brushes had about 25% left compared to the replacement brushes. I was just wondering if alternators are replaced just because the brushes were worn out.


Nah, you're not lost in space... if you've owned that honda for nearly 30 years/400k miles, and you've never even replaced the bearings in that alternator, you're doing something right. Keep doing what you're doing - up at the front of the bell curve.
 
Originally Posted By: OneEyeJack
I must be lost in space. My 84 Honda Civic (I'm the original owner)

I hate you already: you get to keep driving your loved one. I'm up in the north-east, where RUST is the limiting factor for daily-driver car ownership. You have even wackier government than we do, but at least your cars don't crumble out from under you.

Originally Posted By: OneEyeJack
has a bit over 400k miles and I've replaced the brushes twice, and the alternator is working like new. Both times the brushes had about 25% left compared to the replacement brushes.

Those Denso alternators are just about bulletproof. Just keep replacing brushes and they'll outlast the car.

Originally Posted By: OneEyeJack
I was just wondering if alternators are replaced just because the brushes were worn out.

I would not doubt that one bit. I'll bet many people will pull their apparently-failing alt (not even thinking of the brushes), take it to AZ, have them proclaim it "bad", and then buy a total-garbage aftermarket reman. Then they'll spend the next five years replacing that aftermarket reman, every single year.
 
Years ago I bought an 86 Accord for cheap because the alternator light was on. When I got it home I discovered why, the axle had to come out to remove the alternator. Guessing it might be the brushes I was able to change them on the car by unbolting the alternator and flipping it on the side for access to the brush assembly. Cost about $5 at that time. Worked fine till I got rid the car.
 
I only saw one guy do this, and it was a disaster.

Once he had his older Mitsubishi made alternator apart, he couldn't put it back together. He then ordered the only rebuild he could for $250, and the parts store would not accept his messed up alternator as a core, costing even more.

So I buy high end reman alternators whenever possible
 
Status
Not open for further replies.
Back
Top Bottom