94 Olds 88 Cold Weather Brake Problem

Hi, I had posted about 8 months ago about this problem and never got a reply. Brakes on the car worked perfect all summer but now that the cold weather is back I am having some problems. When I start the car, I put my foot on the brake pedal. Pedal is hard. Put the car in gear, try to brake for the first time, and I have no brakes at all. I pump a few times and they come back. Brake goes from hard to soft before they fully work. Once I get by the original start up they work fine all other times. We have bled and bled the lines. Criss crossed from the front to the back lines (x pattern). Still not working right. Tried having the key on when bleeding, didn't work. Could it be the master cylinder? Is there a special way to bleed the lines when they are ABS? Something special with this model?? There has gotta be moisture in there someplace since it is only a problem in the cold. Any ideas are greatly appreciated. Son is currently driving the car. Thanks

Does no brake at all mean the pedal is rock hard and no stopping, once you get past this issue is the pedal seem like a normal height and stopping power?

No brake means the pedal is rock hard. I have to push really hard a few times and then it returns to normal. It works perfectly fine after the initial startup. Pedal feels normal and braking is normal all other times. Problem arose last fall after my husband had to replace a part on the rear brake. It was leaking fluid. I think we have bled the lines at least 5 times. Brakes work perfectly fine in the warm weather. Just acts up in the cold.

Hmm...sounds like a faulty brake booster to me. If the brakes were squishy then you'd be looking into replaing the master cylander but a hard pedal indicates a bad BB.

Agreed.

I appreciate all the input. I did finally break down and send it to the shop. The brake lines near the master cylinder were rusty and at least one had a hole in it. It was sucking in cold air and moisture at every startup.