Piff

I’ve decided to add “unusual” maintenance items to my blog. Hopefully, this will give people inspiration to try things that most people would bypass in the name of convenience or because they haven’t tried the procedure before. This link refers to the original conversation about it on the forums: http://www.dfwmiata.com/showthread.php?15020-Gonna-replace-a-dead-radiator-fan&highlight=

We did this over a year ago, and I’ll be honest at this point and tell you that my father, an old engineer from back in the day, knows all about this stuff. I sadly don’t have that kind of training. I also apologize that this isn’t really a how-to either as I was mostly a passenger on this one. I will say this; whenever you’re working on something small, consider holding it over a tub or other container. That way, if parts come out, you hopefully won’t lose them on the garage floor.

When I got the car home the first day of purchase I noticed that the radiator cooling fan wasn’t coming on. We made sure to check the electrical connections first and indeed, the fan plug was receiving 12 volts when switching on the cooling system. So the issue almost certainly had to be the fan. I had read about this relatively common malady on the forums, and that most people solve it by purchasing a new one.

I’m a fan (no pun intended) of reusing where I can and keeping things out of the local landfill that don’t absolutely need to be there. So, instead of buying a new fan, my father, brother and I decided to fix the old fan. A fan is just your average electric motor whose purpose is to turn fan blades. It’s a fairly simple piece of machinery with only a few moving parts.

My father’s assumption was that the brushes were worn out. The brushes ride on the commutator and together, they flip the electric field back and forth at the appropriate times. The brushes are made of a soft carbon and wear over time. Although the unit looks permanently sealed, this isn’t really the case. We opened it up and removed the guts.



(Photos of cap off and inside of cap where the brushes are)

The brushes were so worn away that they were unable to do their job, so we cut them out. (Leave most of the braided lead on the motor side!) Now, where to find new brushes? In Richardson, there happens to be a generator repair shop down on Greenville that we went to. The owner didn’t have fresh off-the-shelf parts, so we rummaged through a box of old brushes that he keeps and found two that were close enough to do the job and had some meat left. We paid the man and headed home. If you don’t have a local source for your area, we found an online supplier that looks like it might be able to do the job. It's http://www.eurtonelectric.com/. I will reiterate that we did not end up using this source, but if you look in the parts area, there are some brushes that are 0.220 by 0.220 by 0.530 (part # 33G) that we think would have done the job with some filing.

Once home, my father got down to filing the brushes to make them fit in the holders while my brother cleaned up the motor, commutator (no scratches…yea!) and casing. The brushes are soft like pencil lead, so we had to file carefully or risk taking too much material away, and avoiding crushing them in the vice that we used to hold them. When they fit right, my father soldered them onto the leads.




(1. Old brushes in back, new in front; 2. The motor cleaned up; 3. Filing the brushes to make them fit. The Ol man can't be bothered to put down the pipe to do it.; 4. The "new" brushes in place. )

We assembled the unit back together after giving it a little lube and I had my father seal it with a little sealant to avoid water getting in. We tested it out and it worked perfectly. Installation was the reverse of removal (Ha! I’ve always wanted to say that.)

Regards.