Brake problem on 1995 Lesabre Custom

1995 LeSabre Custom 140,000 miles
ABS Brakes - No Brake/ABS lights on

when you are going like 50 mph if you push the brakes to stop they go like half way to the floor and you dont really stop to well...

but if you let off and repress the brakes they go about 1/4 way down and work great.

Any ideas? The car isnt mine its my sisters and shes only home like once a month so wont really be able to check anything right away but advice is always nice. :grinyes:

Sounds like the brake booster is a problem. Big round thing on the fire wall.

Check the rear brake adjustment. If that is correct, check the master cylinder.

In addition, check the MC reservoir for proper level of fluid. If low, look for leak between the MC & booster, it will drain down to the bottom of the booster. Also, check rear wheel cylinders for leaks.

well i know its topped off on fluid and i dont think its a booster problem cause it doesnt seem like you have to push hard to get it to brake. But i will look at the adjustment of the rear brakes. i believe it needs new rear drums and shoes anyways cause the front brakes look pretty new but the back end feels like ovals when you brake hard :rofl: