Power surge when braking

2006 Lincoln Towncar engine accelerates when foot brake depressed. Happens infrquently – Lincoln mechanics can not relicate or correct

To me, when that happens, it is usually related to the master cylinder booster diaphram or the vacuum line between that and the intake manifold. But 2006 is pretty new to have something worn out. I’d look for a loose line or perhaps a damaged line. Wiggle, feel all along the line, use a mirror and flashlight if you need to in order to see every inch of that line. There could be some other oddity relating to the brake switch, which goes to several places including your brake lights, cruise control, ECM or computer, etc.

OK. I’ll be the one to ask. Is your foot touching the gas when you depress the brake? Before you say NO, understand that the obvious is always the thing we don’t even consider and refuse to admit as a possibility. Also, look for floor mat movement which pushes the gas when you push the break (your heal pushing the mat forward). I had that happen to me. If the mechanic could not replicate, you have to wonder.

The answere to your suggestons is no.
I will take the suggestions for inspection to my mechanic.I think Lincoln doesnt want to admit they have problem they can not fix.

BTW you are about due for a bake fluid change (3 years). If that is the original brake fluid it is about time to have it changed (flushed). Brake fluid absorbs water and that can cause rust and most important it can start to boil when going down a long hill using brakes and you can loose your brakes due to that water boiling.


Is this a big event, or just a slight surge? I think that your 06 has throttle by wire, and it seems like those do give an ever so slight power surge when braking lightly sometimes.

I have experienced it when braking lightly and pumping the brake stops the surge, My wife has had two accidents that indicate a strong surge

Thanks for the comment

I’m with Bennie on this. I’d look first to the booster and its vacuum line including the check valve. The booster uses the engine vacuum pulling a diaphragm to assist you in braking, and if there’s a leak in this system upon initial brake pedal activation it could cause air to be drawn in for which the ECU could compensate by lenthening the injector pulsewidth (adding gas). The check valve is to keep the vacuum going in one dierction only, but the leak could be there also.


The Lincoln has a feature that raises and lowers the brake pedal and the accellerator. They are linked togrther so that they raise and lower together.Obviously they are linked. Is it possible that the problem is in this system?