Talk:Brake bleeding/Temp
From Wikipedia, the free encyclopedia
Brake bleeding is the procedure performed on hydraulic brake systems whereby the brake lines (the pipes and hoses containing the brake fluid) are purged of any air bubbles. This is necessary because, while the brake fluid is an incompressible liquid, air bubbles are compressible gas and their presence in the brake system greatly reduces the hydraulic pressure that can be developed within the system.
The process is performed by forcing clean, bubble-free brake fluid through the entire system from the master cylinder(s) to the calipers of disc brakes or the wheel cylinders of drum brakes). It can be done easily by two persons working together and doesn't require much technical expertise besides a basic knowledge of brakes and car hydraulics. One wheel at a time, the brake bleeding valve for that wheel is opened while a drain hose is attached to that valve and immersed into a pool of brake fluid. The assistant then pumps the brake pedal. In this manner, fresh fluid is forced through the system into that wheel's caliper or wheel cylinder, and any old, dirty, water-saturated or bubble-entrained fluid is expelled from the system. When the fluid from the caliper or wheel cylinder runs clean, clear, and bubble-free, the brake bleeding valve is closed and the drain tube removed. The process is then repeated for the remaining wheels. During the entire process, the brake fluid reservoir must be kept full of fresh fluid lest new air bubbles be introduced into the brake system.
More sophisticated automatic systems allow brake fluid to be forced under pressure from the brake fluid reservoir into the entire system. Using these devices, no assistant is required.
 |
This automobile-related article is a stub. You can help Wikipedia by expanding it. |
