I have a 1999 4Runner V6 2WD with about 115,000 miles.

Occasionally, I hear noise coming from my front driver-side brake.

The sound is identical to gentle screeching sound indicating the pads need to be replaced. But, I had my front pads and rotors completely replaced at about 25,000 miles ago (Performance Friction pads and Brembo rotors), and I still have plenty of pad thickness left. Also, the sound only comes from the driver-side front brake.

Any ideas on diagnosis and cure for this problem?

 

Your title probably hit the nail on the head. Replace em.

 

Replace the calipers? Is that necessary - in other words, is there no fix without replacing - like grease, etc.?

 

In my experience, by that age, brake calipers/pistons/cylinders can get hung, or stick, essentially, "go bad". They don't cost that much, my practice is to buy new loaded calipers, turn the rotors, (or replace if they are already cut down too much). Don't scrimp on your brakes.

 

There's nothing to grease on fixed calipers, so no dice there.

A caliper rebuild kit from Toyota is $25 or so, and it does both calipers. Takes a few hours to do.

Compare that to $80+ each for a reman caliper.

Hell, you do 90% of the work to install a reman caliper, why not just take another 20 minutes to replace the boots and seals and save $150?

Rebuilding the calipers requires compressed air, though. No way you can do it without it...

 

I made a tool out of wire to pull the pistons out and it is still a pain napa sells rebuild kits for 10$ per side.

you do save money doing them your self but it is time consuming also if the pistons are pitted I would suggest replacing them.