Cadillac Repair: Brakes, manual brakes, vacuum leak

Question
I have a 1990 Fleetwood and while driving I lost power in the brakes then I pulled over and check the fluid in the master cylinder. Everything looked good and continued to drive and the lost of the power brakes can back. It was raining that day so there were some area with minor flooding. What would be the cause for this?

Answer
Hi Cecil, The pedal doesn't go to the floor it just feels like manual brakes right? Then if your car is a front wheel drive Fleetwood then I would suspect that the vacuum pump is weak, the filter is restricted at the pump outlet, the relay for the pump is intermittantly working or you have a vacuum leak in a hose or fitting somewhere. You will need to take a vacuum reading at the pump and then at the brake booster hose. if there is a differance in readings then look for a leak. If the readings are the same but the pump can't pull 21 inhg after 10 seconds then the pump is weak and needs to be replaced. If it can then the brake booster might be at fault. Hope that helps. Bill