Manual brakes 68 camaro

My 68 camaro loses small brake fluid from the small resevoir. I dont see any leaks. Any help??

My 68 camaro loses some brake fluid from the small resevoir. I dont see any leaks. Any help??

Look under the dash, drivers side at the firewall. Check to make sure brake fluid isn’t running down the firewall from the brake master cylinder.

Tester

Is the small one in the rear? If so, it could be being sucked into the booster and into the engine. You would need a new seal at the rear of the master cylinder. The loss could also be at one of the rear brake wheel cylinders or the rubber hose between the hard lines at the rear differential.

Manual brakes = No brake booster.

Tester