Originally Posted by Grandpaswagon

Brake fluid will absorb moisture over time and lose performance over time. It is a good idea to flush out your brake fluid and replace it every couple of years, especially if you live someplace with a lot of moisture. I personally flush and replace my brake fluid whenever I do a brake job.

Flushing out the rear end and tranny should also be done from time to time. Gives you the opportunity to check for abnormal gear wear and any possible damage. Plus, you can replace the stock gear oils with good quality synthetic stuff and that can help improve gas mileage a bit.

Originally Posted by torque_is_good

it's also an opportunity to paint the diff cover or replace with a silver/chrome one

don't forget that the more you say you need to do under the car the longer the nap you can take while you're under there and family/friends leave you alone.