ABS/Brake lights flash, Hard braking

Whenever I touch the brake pedal my ABS and Brake lights come on for a second or two, then go out. If I'm making a normal stop, everything's fine. However, if I press the brake pedal hard to try to stop more quickly the pedal gives a lot of resistance for a second, then allows me to stop normally. What's going on???

This is all on a 1990 Olds 98 Touring Sedan with ABS. When I called the auto parts store today to ask about the price for a new master cylinder, thinking that might be the problem, he told me the ABS version comes with the master cylinder, booster, and something else (can't remember right now) all integrated together and costs over $1000. Help!

Did you ever get this problem figured out? I have the same problem with mine. It's a 1989 Touring Sedan and I don't want to spend a thousand dollars on it to repair it. Thanks.

sounds like your power brake booster is going bad? check the hose leading from booster to your engine and see if it's got a leak going to motor in the rubber hose.

homaydo, welcome to AF, 5 year old thread here, not much chance of the OP replying, please look at the dates before continuing a dead thread, thanks.