Mercury Marquis owners have reported 1 problem related to power assist brake vacuum (under the service brakes category). The most recently reported issues are listed below.
Mushy brake pedal when applying brakes. Dealer notified and replaced booster assembly, and condition stil occurring. Brake booster assembly failed twice. The brake pedal is still noisy and the brake booster replacing did not solve the problem.
See
all problems of the 1996 Mercury Marquis
🔎.