Q: I blew a brake line last night, replaced line.bled brakes from master cylinder, brakes very squishy

Both improper bleeding and a failed master cylinder could be the fault. Running the master cylinder dry can lead it to fail quickly. The primary seal on the master cylinder piston will tear easily. Make another attempt to bleed the brake system. Start by bleeding the master cylinder. Have a friend pump the brakes. NOTE: Have the person pumping the pedal for you place their left foot under the brake pedal. You should never pump the pedal to the floor or you WILL damage the master cylinder piston seals if they’re not already damaged. Bleed each line at the master cylinder then go to the wheels. Make sure the brake fluid reservoir does not run low during the entire process. Start at the wheel furthest from the master cylinder - the right rear wheel. Crack the bleeder screw loose and allow it to gravity-bleed - let the fluid just run out on it’s own for a moment. Then tighten the bleeder screw and have your helper pump the pedal 3-4 times between each bleed. Crack the bleeder loose again and repeat the process 3-4 times at each wheel as you move closer to the master cylinder. Right rear, then left rear, then right front, then left front. If bleeding the system like this does not restore the brake pedal, then in all likelihood, a master cylinder replacement will do the trick.