I replaced the master cylinder again, and re-bled the whole system, this time making sure the hose on my bleeder ran above the bleeder valve. There is NO air coming out of the system anymore. It stops now, but just barely. It’s driveable, but not to the point where I would feel safe driving it on the highway.

Do S10’s and Blazers just have really horrible brakes? Is it not possible to make it stop reasonably?

That’s a good point. They’re in good shape, but I assume they’re original. I’m going to replace the calipers and wheel cylinders, and I’ll look into getting steel braided lines to replace the hoses with. Right now though, it still seems like the problem is air in the lines. I have put about 8 quarts of brake fluid through it though. The only thing I can think of at this point is that air is getting in through the ABS unit.

I’m pretty sure I have the correct master cylinder. I replaced it a second time, and it’s better. I can drive it now (I drove it to work today with no problems.) But it still doesn’t stop like it should. I bought new caliper pins because the existing ones are rusty, so hopefully that will help reduce noise. The main thing that I need to do is get the air bled out of the ABS unit, and since we likely won’t get any more measurable snow until fall, I’ll have to find another way to get the ABS unit to activate so I can bleed it again. I’m sure there aren’t any leaks because my fluid level is staying consistent.

I’m the next few weeks, I’m going to start sanding the rust on the roof and find a color-matched paint for it. I’m also looking for someone locally who can rebuild the steering box. All of the companies that sell rebuilt steering boxes have pretty terrible reviews, so I’m nervous about buying one.

The tie rods I installed in December are already shot. The boots cracked wide open and leaked all of their grease out, so I’ll be looking to replace those too.