Please help with brake problem

[scottp6]

This is for a 94 cutless ciera cruiser (wagon), with ABS. I have pretty much lost my brakes. The pedal hits the floor when you try to stop. It will stop though. I assumed possible leaky wheel cylinders but see no sign of leaking fluid near the wheels. Took off the drums and they don't look like they are leaking to me. They have alot of powdery black crude on them but no signs of fresh fluid. The fluid level has dropped twice. If I pull it in the garage and pump the brakes with the car off or on I see no signs of fluid on the floor nor a change in fluid level, but the fluid level drops if it is driven. Should I see leaking fluid if I am not driving and just pumping the brakes?

I haven't checked the front yet with the tires off, just visually by sticking my head and there and don't see any signs of leaking after a quick inspection.

The pedal has resistance with the car off and with the ign on, but drops to the floor as soon as you start the car.

Could this be the master cylinder or booster?

Any thoughts or ideas on where to check next?

Thanks in advance for your help, need to get this back on the road quickly, it is my MIL's car and the brakes went out while I had it.

Scott

[maxwedge]

First go over the calipers and lines looking for a leak, if you are sure there are none, than the fluid could be going into the brake booster, it has to go somewhere, no?

[scottp6]

I was wondering if fluid could get back in there. Is there anyway to verify if it has fluid in it with out taking it completely out?

[maxwedge]

You may be able to partially remove the m/c and see if the rear seal is leaking.