Brake problems

You MUST replace all rubber parts that contact the brake fluid. That includes rear wheel cylinders, rubber hoses, and the combination valve under the master cylinder. Until you do, the contamination will leach out of them and ruin your new parts again. The steel lines must be flushed and dried too.

Once all the rubber parts are replaced, do the normal bleeding process, then we'll continue on if necessary. You do not have to replace the power booster because its rubber diaphragm doesn't come in contact with brake fluid. If the car has anti-lock brakes, the hydraulic controller must be replaced too because it has rubber seals and o-rings inside.