Bad Brake Booster?

[faeasjepardo]

Hi guys, I've searched the forums and got some info on this, but wanted some more opinions.
So I took my 89' 240 hatchback for inspection, the guy said my Brake Booster was bad and that is why my brake pedal gets stiff sometimes. A few weeks back I had to replace my Brake Stoplight Switch, which involved taking off the entire brake pedal. Would it have been possible for an air bubble to get in my brake line from doing this?
I bled my brakes when I got home.
I have tested the booster by pumping the brakes a few times, then starting the car. After 3 pumps the brake pedal gets stiff, and then when I start the car with my foot on the brake pedal, the pressure releases and the brake pedal feels normal. I drove around for 10 minutes and it seems to be fine.
Thank you for any help.

[compactfean]

There is no way for air to get in the system from the pedal. If you have ever done a brake master cylinder you will see the only thing that touches the bmc is a push rod type deal in the booster. And if you did get air in the lines somehow it would make the pedal spoungy. If your pedal is hard only sometimes I would check the one way check valve to the booster that is located right in the middle of the firewall. You should be able to blow through it one direction. (Air flow going taward engine) and not at all the other direction to booster) it is dupposed to hold vac. If your car is turboed.that will act as a huge vacuum leak.

[faeasjepardo]

Thank you for the reply I will check that valve.