Two problems related to power assist brake have been reported for the 1997 Chevrolet Blazer. The most recently reported issues are listed below.
The brake power assist unit was replaced but the brakes are still not functioning well. I had the dealer check them and they said they checked out ok.
Brake vacuum booster failed unexpectedly at 26000 miles resulting in dangerous loss of pedal pressure. . The part was replaced at midas with a genuine Chevrolet replacement part. I still have the defective brake booster in a box in my garage. Would you be interested in examining this part? I would be willing to ship it to you. Given the number of brake failures and problems with chevy Blazers, this should be worth looking into before a brake booster failure kills or injures someone. When this part failed, it was extremely hard to stop the vehicle.