When I started stopping at a red light, I had a frightening thing happen. The car wouldn't slow down! I had to press down on the brake pedal with both feet to get my car to come to a stop. There were no warning signs and no warning lights came on. This problem keeps happening on an intermittent basis. I went to an independent mechanic and he told me that the problem is the brake vacuum pump. Before I have him replace it, would you please give me your diagnosis and solution for my car?
Yes, this is a possibility. Due to engine on this BMW having variable valve lift engine vacuum not always present, a vacuum pump is installed to supply sufficient vacuum to run auxiliary systems such as the brake booster. The vacuum pump system needs to be checked to ensure if sufficient vacuum is being produced by the pump and the system integrity should be checked as well. You may want to enlist the help of a certified mechanic, such as one from YourMechanic, who can check and access the vacuum pump to properly diagnose the brake issue and have this resolved.
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