we just bought a 93 grand for my wife about 2 months ago and the brakes have been acting up ever since we got it. Most of the time when you hit the brakes they will stop quick but every once in a while when you need them to stop quick and you hit them they act like they are not even trying to work. It has the 4.0 and ABS. I don't know alot about the Grands and with it being newer than 89 I have no idea. Oh and the brake light will come on on the dash at different times. thanks in advance.
mike

 

Mine just went through this and it was the master cylinder.

 

the pedal is not soft or anything I was thinking it had some thing to do with the ABS. is there anyway to disconnect the Abs and see how it does?

 

Is the yellow ABS light on, or just the red brake light on, or both on?

 

mine wasn't soft either until it finally quit. It went soft about a week before they failed. Before that it was just like you describe.

Could be something else, but just sayin

 

its just the red brake light on the dash

 

thanks I'll have to take a look at it

 

Ok, the red light is only for the hydrailic side of the braking system, you have a pressure differential problem. Most likely a bad master cylinder. The yellow ABS light is for the ABS side only.

 

Red brake light also means that the master is low on fluid. One of two things, your brakes are very low all the way around, or you have a leak somewhere, like a mastercyl or a caliper.

Either that or you are driving around with ebrake on, and I dont think thats the case lol

 

You're not driving it like that are you? Had an El Camino have full brake failure once coming down a freeway overpass heading straight for a red light! That was quite the scary ride and a damn fluke I didn't crash into something/someone. Even the E brake failed!

 

when i can get into a garage or the weather breaks I'm going to do a brake job on it along with a few other things but yes we are driving it and it is not leaking any fluid. we have had it for about 3 and half months and I've kept an eye on the fluid and it has not lost any. so i don't beleive it has a fluid leak, maybe a vacume but not fluid.
mike

 

Just be careful, my master cylinder failed at a really, really bad time and when it went L1 was my best friend because the pedal went straight to the floor.

 

Heres a test for you. Shut the vehical off. Pump the brakes a few times to relive vaccume pressure. Then put steady pressure on the pedal. is it hard? If it is hard, start the vehical while your foot is on the brake, does it drop or get softer? If it doesnt drop somewhat, or get much softer you probably have a bad booster. If it drops to the floor, then it is a master.

 

You don't have to loose fluid to experience failure. In my case the fluid was getting past the cups in the master cylinder, so for months i did not loose a single drop of brake fluid. Then after having the same issues as you, one day poof, no brakes.

 

thanks guys I'll have to check it out good