TrentC

The ABS light is now permanently on, and the groaning has stopped.

I found a unit at a salvage yard. Seems only the 94s had those units in them as even 93, and 95 did not have them in it. It seems those 90s models still quite popular as all the vehicles were nearly stripped bare.

Since the groaning stopped, I assume the ABS has failed altogether. However, pressing on the brakes seems to need more pressure than it should to bring the vehicle to a stop. I think a woman would have trouble bringing it to a stop, I have recently replaced the master cylinder and brake booster , but that has made no difference,

Sabino56

Well at least the question where the groaning was coming from is settled. When you replaced booster, memory is there is a spec on space between the booster and push rod. I imagine it was part of replacement instructions but just in case it wasn’t, something to check. Also - did it come with new vac check valve or you use the old?

you could try something like cowboy trucker did. https://www.chevytalk.org/fusionbb/s...hp?tid/358919/ though it seems it would just be masking the problem and probably better to find the reason and fix before improving the pedal feel with the upgrade.

is the that pedal travel is good but just requires a high force or is pedal long and also a high force required? I had long pedal and it felt hard to stop when I was messing with my brakes. I pulled abs and it wasn’t the problem. I replaced rotors, pads, soft lines, MC, rear brake shoes, checked booster, - only thing I thing I didn’t replace were the rear drums. Turned out the rear drums were my problem. They were original and too worn. Even with new shoes it required too much travel by brake cylinder to engage, I guess. Replacing drums tightened up everything, reduced pedal and improved feel. I’m not sure why long pedal also made it feel like it required more force.

TrentC

It did have long pedal travel, so I replaced the master cylinder. That resolved that issue, but still a lot of pressure to bring the bring the vehicle to stop. I replaced the booster way back in 2013, so I do not recall what went into that I recall I had an 88 Sub , and it was having a similar issue. I changed the front brake lines going directly to the brakes, and that resolved the issue a lot. Maybe I will do that, and consider Raybestos master cylinder from the other thread you linked to.

Thanks!