Break fluid leak?

[Breeze77z]

My '77 280z consumes break fluid...It hasn't really done it in a while, but i went to go somewhere today and i backed out and the pedal almost went to the floor, not all the way though and i did have some brakes, but no where near what it usually is. I'm not happy with the fluid i've been using most recently, but they didn't have what i usually get and it was the only dot 4 in the place, and i wasn't sure mixing dot 4 (what is in there) with dot 3 or so on. It's really clear fluid compared to the more golded color of the other stuff, its Prestone and i used to use the white bottle with blue label and red top (sorry i can't remember the name). There were no puddles of ANY fluid on the ground under/around my car, no wet looking spots near any major connections that i could see, is there anywhere inside that might leak?

Thanks for any ideas.

Pat.

[blueovalz]

The leak may be at the back of the MC (at the booster). This is a hard leak to find, but with the loss of an entire reservoir's worth of fluid, I would be surprised it has not shown up at that junction.

[Mike C]

I agree with Terry. Fix it sooner rather than later as the fluid tends to destroy the booster.

[Guest Anonymous]

Your brake fluid leak might very well be at the master cylinder.The signs should be evident by dampness on the vaccume booster and wkinkeled/blistered paint on the vaccume booster and surrounding aera. I would also visually inspect the rear wheel cylinders for leaks.