I want to replace the brushes on the Denso alternator. Alternator is out of the car but two rusty Phillips bolts are preventing me from taking out the brushes.
I have sprayed penetrant on them and left them to soak and change their minds overnight.
Any tips on getting them loose?
I have the proper Phillips #2 screwdriver (no luck so far). Thinking of using a drill/impact wrench with a driver. It would be hard to cut a flat on the heads due to limited space and I don't want filings around the alternator.

Thanks again,

Dan

 

Use a #2 bit with serrations, it will help prevent cam-out.

A power impact driver is good, but even a manual one will probably work:

http://www.harborfreight.com/7-piece...set-93481.html

 

The manual impact driver is a good idea.

Or ...

rap the handle of the screw driver with a small hammer to break the corrosion loose

then, push down on the handle of your screwdriver with your chin as you turn it

sometimes a pair of visegrips on the screwdriver shaft helps

you can also turn the screwdriver while maintaining lots of downforce while someone else taps the handle with a hammer.

whatever you do, don't let the screwdriver round off the screw. that's why you always push into the screw.

 

What a job that turned out to be!
The RH Philips screw was very hard to get out.
Thanks for the tip on the impact driver from HF. It worked a treat on the LH screw (regulator to right).
In the end, after lots of penetrating fluid (which did not penetrate very well) and some inadvertent bending of regulator contacts, I got the brushes out attached to the regulator.
I supported the stuck fixture with a 7mm socket and whacked away on the impact driver. That screw had amazing tenacity for something so small.
Eventually, it came loose. I replaced all three Phillips screws with ones from Home Depot. Corrosion was evident on the securing lugs of the brushes and on the screws though the threads did not strip.
After 142k miles the brushes looked like they had another few 10k miles left. Replaced brushes. Straightened regulator contacts and patched cracked plastic supporting lead to diode with epoxy. Bearings had no play and were spinning free. I let sleeping dogs lie on the bearings. If necessary, I could have got another regulator off of eBay. I cleaned the slip rings with 320 sandpaper and a green plastic kitchen scourer. Cleaned off with contact cleaner.
Used a long bolt and 22mm(?) socket to push back the metal bushing that helps to secure the alternator to the motor mount. Very important to do this.
The alternator runs fine. 13.99 V at idle. 1 V up from before and headlights are brighter.
While I was in the neighborhood, I replaced the water pump, thermostat tower (alloy kit, at 142k miles the plastic one was on its last legs), thermostat and idle pulley. The bottom radiator hose had blown off the thermostat housing a few months back and the plastic housing was going soft.

Fun and games by Jag.