Purchased 95 Monte LS a few weeks ago. I bought it knowing the it needed brake work.
( I am laid off so backyard mechanic time).
I had to replace the RR brake cylinder and brake line from the mid body point.
We bled RR line and it seemed to be fine for about a week.The pedal wasn't firm but it wasn't overly soft either. The ABS light and Brake light would come on intermittently, and was figuring I needed a complete bleed.

During week 2 the brake pedal got pretty firm for a day or 2, then it suddenly went completely soft, to the floor and the Low Trac would kick in at a complete stop. I also started getting a clicking sound from the front wheels while turning and braking.

Inspection showed no leaks and fluid level in the Master Cylinder was the same.

The front rotors and Pads appear fairly new and in good shape.

I decided to replace the both rear drums and pads while I had the car in the air.This time bled both rear lines and the ABS ports on the MS (lots of air).
Everything seemed to have firmed up after that, but as soon as the vehicle was started the pedal is to the floor again, and the Low trac commences to kick in.

To my knowledge the Master cylinder was never emptied out, which is the reasoning for not bleeding the front brakes yet.

I've read about ABS sensor issues and was wondering if there is a good diagnostic plan I should follow to get this straightened out. I have a couple of mechanics that I can call on, but I need to be cost effective in getting it fixed.

TIA

 

I honestly don't know where to guide you on this one....

But, if it was me, I would bleed the entire system all at once, not just the front or rear.

Sorry I could'nt be more help.

 

wow, that sounds bad. i know i had an ABS light on, but i jumped the ciruct with a peice of wire so it could go through inspection.
maby your problem has somethign to do with the bower brake booster? just a thought.

 

Pretty sure its an ABS issue now, the brakes are working fine (w/ some adjustment), but the Low Trac keeps trying to kick on... Hoping to get the sensors read this week...