Cadillac Repair: POWER BRAKE BOOSTER, 1990 cadillac fleetwood, power brake booster

Question
I HAVE A 1990 CADILLAC FLEETWOOD AND MY BRAKE PEDAL ONE DAY GOT VERY HARD ON ME. I TOOK IT TO A MECHANIC AND SAID THAT THE POWER BRAKE BOOSTER NEEDS TO BE REPLACE. COULD YOU PLEASE TELL ME IN STEPS/DETAILS WHAT THE MECHANIC NEEDS TO DO IN ORDER TO COORECT THIS MATTER. I WAS TOL D BY SOMEONE WHO HAD THIS DONE AND THEY STILL HAD A HARD BRAKE PEDAL. THANKS.

Answer
There are 2 different brake systems that were used in 1990. Are you POSITIVE that you have a big black round pancake shaped vacuum unit mounted behind the master cylinder attached to the firewall ?.

If your NOT sure which brake system you have: e-mail me a picture of the drivers side firewall in the engine compartment. E-mail it to: onlineautohelp@msn.com