Clogs in break lines can eventually let pressure build up in your vehicle's caliper, so they're hazards to your and your vehicle. If you have a clog, you need a procedure called a brake line repair. You can do a brake line repair yourself if you're accustomed to working with vehicles, but if you're a novice, it might be a good idea to have a professional do the job.
You need to find the clog first to determine which brake line to work on. You will need to hoist the car, so you can easily see all the brake lines. It may be necessary also to remove the tires from your vehicle, so you have access to all the brake lines.
If it's obvious immediately to you where the clog is, you just can remove the line that is clogged from the master cylinder. If it's not obvious, you can take each brake line off, one by one, and put some compressed air through the line. If the airflow is constricted, you have a clog.
Once you've removed the clogged brake line from the master cylinder, attach a new line in its place. Once it's securely attached, pump your car's brake pedal to get air back into the system.
You need to "bleed" the brakes before you begin driving again, according to Cars Direct. To bleed the brakes, locate your car's bleeder valves (this information should be in your owner's manual). Loosen those valves with a box wrench.
Remove the master cylinder reservoir and suck out as much liquid as possible with an object like a turkey baster. Once you've removed as much liquid as possible, you can use a clean rag to wipe out any residue.
Get a length of clear plastic tubing and push one end of the tube over the brake bleeder bolt at the right rear of the car. Put the other end of the tubing into a waste bucket or bottle with 1 or 2 inches of clean brake fluid in it. Top off the master cylinder reservoir with fresh fluid and put the cover back on.
With someone applying pressure to the brake pedal, turn the bleed valve a little bit, until some fluid trickles into the waste bucket. When the trickling stops, close the valve and remove the pressure from the brake pedal.
You need to repeat this process until clear brake fluid comes out and then repeat on all sides of your car's brake system.
