Toyota Repair: 1994 camry brake fluid leak, external signs, fluid leak

Question
I have a 1994 Camry, 2.2 L, 4 cylinder engine. I noticed a few days back that my brake fluid level was low. I purchased DOT3 FMVSS no. 116 grade brake fluid. Then immediately (after about a day) after some time my brake fluid level indicator showed the level was low. I kept
refilling the brake fluid without any signs of brake fluid leak under the car. Someone at Autozone suggested that it could be internal brake fluid leak. What is your opinion on this?? Any idea how much could it cost to plug the problem?


Thanks  

Answer
If the brake fluid disappears from the reservoir then there must be a leak somewhere, some common areas for external leaks are the rear wheel cylinders, remove the brake drums to inspect, or a leaking master cylinder, remove the master cylinder for inspection of a fluid leak at the rear, if that's the case the fluid will leak into the brake booster with no external signs of a leak.