No. The booster only makes it easier to push the pedal. If the brake fluid reservoir is not empty suspect internal leakage in the master cylinder. If it is empty look for fluid running down the inner sidewall of a rear tire, and look for wet spots on top of the rear axle and along the left frame rail. If no leak is still found, check if the front brake pads are nearly completely worn. Also unbolt the master cylinder and pull it away a little from the booster to see if it's wet in back. The brake fluid can leak into the booster and be burned in the engine.