When I try to bleed my brake system using the Mityvac pump I am getting air bubbles in the line connLast Updated: July 25, 2019
Usually this condition is caused by a small amount of air being pulled between the threads of the bleeder screw and the body of the wheel cylinder or caliper resulting in the appearance of several small bubbles in the line connected to the bleeder screw. This can be corrected quickly and easily.
Before you begin to bleed the brake system we suggest that the bleeder screws be removed at all four wheels. With the bleeder screws removed assure all are clean and the passages of the bleeder screws are free of corrosion or debris. (A small paper clip will work well.) Next, be sure that all brake fluid, penatrating oil, and or grease is removed from the bleeder screw. (Brake cleaning solvent does an excellent job.) Apply a 2 to 3 inch piece of Teflon® tape to the threaded area of the bleeder screw only. Wrap the tape in the opposite direction of the rotation of the threads. This will prevent any see page of air from around the threads.
Install each bleeder screw back into the corresponding caliper or wheel cylinder and lightly seat the bleeder screw. Now you are ready to begin bleeding the brake system! This may seem like quite a bit of work in the beginning, but, once you get started it should only take minutes to complete. In fact, the procedure outlined above is an important step when bleeding brake systems regardless of the method used. It is critical to be sure that each component in the brake system is in proper working order to assure a long lasting repair. Remember, the brake system is the most important system in your vehicle. If the brake system fails to perform correctly, the results could be disastrous.