bill67 wrote on 07/12/09 at 13:30:46: In almost 40 years and many miles of riding I've never had to add and have never changed brake fluid,And for some reason the brakes always worked,One bike was 25 years old rode once a year 5 miles.Never changed in a car either.
Dumping old brake fluid that has absorbed moisture from the air will add to the life of brake calipers and wheel cylinders.
A friend was towing his horse trailer down Mt. Adams a couple of years ago. While doing heavy braking his brake pedal went to the floor. He managed to get the rig stopped using his parking brake and downshifting. After he'd changed his shorts and taken several deep breaths, his braking was OK. His mechanic said that this brake action was exactly what happens with old brake fluid full of moisture that flashes to steam from the heat of heavy braking, then cools and brakes OK later. I don't know why he didn't downshift early before his brakes heated, nor why his trailer brakes didn't help more, nor why his mechanic didn't flush the brake fluid as a routine.
Two nearby fatal wrecks...one was a motorhome coming down a steep mountain road with midwesterner flatlanders driving (didn't downshift early and sufficiently to relieve the brakes of the total job of speed retardation). The driver and another died. Other family members told of the driver shouting that the brake pedal suddenly went to the floor and the rig didn't slow. Another was down a steep hill in a state park where a child bystander died. The State Patrol report reason for the wreck was of overheated brake fluid, not glazed linings.
Flush that brake fluid regularly. The right way to come down a long downgrade, especially when heavy, is to downshift to a gear that almost holds the rig to the speed you feel is safe, then brake moderately hard to get below your safe max speed, get off the brakes and let them cool, brake again, cool them again, etc. I know, a brake job is cheaper than a transmission job...unless you crash.
Ero,
Don't sweat the level. As long as there is fluid in sight, you're good. The fluid level drops normally as the pads wear, and is pushed back up when you push the piston in to renew the pads. As long as you don't see a puddle of fluid on the floor or ground where you park, and the brake action is firm, not spongy, no worries.