2004 Focus ZX3 does not stop in reverse

kevooooooo

This car has been in the shop non-stop. The engine revs regularly & have had four instances when backing up into my driveway and the car does not stop even if I stand on the brakes. Only way I could stop the car was to slam it into reverse. The car was going very slowly, but still.
I have had the brakes fixed, the electronic throttle control replaced, the manifold intakes replaced, the coil replaced. The battery cables were corrupted, causing them to get up to 400 degrees+, alternator replaced.
The Ford dealer I went to didn't see the non-stopping when they tested it when I took it in. It doesn't do it all of the time, but it is a repeated problem for me. What could be causing it to not stop? It is an automatic.

kevooooooo

Sorry, I meant to say the only way it would stop was to slam it into PARK, not reverse. The problem was that it would not stop in reverse.

thecardoc3

When the problem occurs are you saying that the engine is revving higher than normal and the brake pedal is very hard to push?

Try this. With the engine off, pump the brake pedal about five times. Then release it.

Wait five seconds and then hit the pedal one time. Does the pedal feel the way that it does when the problem occurs?

I suspect that you are losing brake booster operation, but why that is occurring needs to be proven.

kevooooooo

The engine revs all the time when idling. That can be observed within seconds. The problem with the not stopping in reverse is unpredictable, as far as I can tell. Each time that I've seen that I had pretty much just started the car up, backed up.
The car is at the dealer, so I'm unable try your suggestions right now. I do appreciate the help though. I've spent $3300 fixing a $36000 dollar car.
It has about 114,000 miles on it.

kevooooooo

When I've had the reverse problem, it feels like I have the brakes on, but I'm being pulled by a dump truck.

kevooooooo

Should have said "$3300 on a $3600 car. Only $300 more until repair costs pass the purchase price. That will probably happen when I pick the car up from the dealer.