odd question on my 1993 Camry LE 4cl.

When I shut the car off after running, i notice the depressing of the brake peddle becoming firm immediately. If no vacuum leaks are present, shouldn;t it take a few moments before the peddle becomes hard to depress from the vacuum leaving the brake booster in the vacuum system if everything is operating correctly?

 

On some cars there is a swish each time the peddle is pushed until the air is bleed off and then the peddle become hard. Don't remember this happening on Camry of the year range.

If there is a leak, typically you can hear it, the engine will idle funny, the brake pedal will push lower then usual.

 

just wondering...the brakes do work great and are tight on this car.