Brake hoses have fitting crimped on their ends.
Look for physical damage to hoses, such as cracking, swelling, or softening from exposure to oil. Check all tubing, hoses, and connections from under the hood to the wheels for leaks and damage. Wheels and tires should also be inspected for signs of brake fluid leaks. Check all hoses for flexibility, bulges, and cracks. Check parking brake linkage, cable, and connections for damage and wear.
Various types of hose damage. Courtesy of EIS Brake Parts.
Woven hoses sometimes experience internal failure, especially when you carelessly allow a disk brake caliper to hang from a hose during service to brakes, suspension, or wheel bearings. Even though a hose appears to be good from the outside, the inside of the hose can be collapsed trapping fluid inside the front brake and causing excessive wear or brake pull to one side. Excessive brake pad wear results when the brakes do not fully release. A partially plugged brake hose will cause the car to pull at the beginning of a stop. When the pressures equalize, the pull goes away.
Internal damage is difficult to diagnose. Depending on which way the internal rubber flap is torn, the hose could cause delayed engagement of the brake or act as a one-way valve preventing fluid pressure from releasing from the brake after application. Internal damage also often results when a brake caliper is allowed to hang on a hose during a brake job.