Mustang creep

I have a 2003 Mustang. The front brakes are new, and back brakes are OK. When I stop at a stop light, and depress the brake pedal firmly, the car continues to creep forward. I have to put it in neutral or park to get the car to a standstill. Any ideas as to why, and how I fix this? Thank you.

What is the engine RPM? If it is idle, your having a serious brake problem that needs to be looked at by a very competent mechanic. If the RPMs are elevated, your having an engine problem.

I’ll second that; sounds like the idle RPM is too high.

Thanks very much.

Thank you. I think you are both right. I feel it probably is the engine idle, and I’ll have it checked out. Thanks again.

You haven’t told us how many RPMs the engine is turning at when you are at a stoplight, but even if the tachometer is showing…let’s say…2,500 RPMs, your brakes should still be able to prevent the car from creeping forward.

On a modern car, properly functioning brakes are more powerful than the engine, and when you “depress the brake pedal firmly”, there should not be any forward movement of the car. I strongly suggest that you have the condition and the functioning of the entire brake system checked by a mechanic other than the one who installed the “new” front brakes and pronounced the rear brakes to be “OK”.

While it is possible that the engine is idling too fast, I suspect some very serious problems with the car’s brake system. This is a safety issue of the highest priority.

does the brake pedal “fade” to the floor or does it hold steady? either way it definitely sounds like a dangerous situation. if it will not hold the car at a stop light how does it even stop the car from any speed?

Thank you. I’m going to drop it at the dealer this week, and I’m going to bring these responses with me.

The brake pedal doesn’t fade. I get a bit of a groan as the car creeps forward. It does brake normally when I come to a stop.

While stopped (in park), press firmly on the brake pedal. Keep the same pressure on it. If it sinks to the floor over the next few minutes (or sooner), you have either an external hydraulic leak or an internal (master cylinder) one.

Thanks very much.