It seems like I've always had problems with the brakes on my '94. I just read a Cardone tech update on brake boosters that said “While a defective booster will cause a hard pedal, a spongy or low pedal requires a hydraulic system check.” Well…that’s my problem. The brakes don't engage like they should and pedal travel isn't all the way to the floor but still further than what feels same.I also noticed aboutaweek or two agoI was low on brake fluid. I topped it offbut had to top it off a bit the other day. With a closed system, that just shouldn't happen! Weird thing is, I don’t see any brake fluids on the garage floor besides some oil creep, and the only squeak I hear is from the front left caliper when I left of the pedal. The double weird thing is that on some days, right after I start up the car, like after work or in the morning, everything works as it should for about 30 seconds. The brakes engage properly, they're tight and responsive,and the stopping power is great. I had a garagereplace the master cylinder on June 13th, so I would be very surprised if that was the problem. In fact, I don’t even recall that completely solving the problem. Before, yes, the pedal was damn near to the floor. Now the brakes are just spongy and sluggish to engage, which has almost gotten me into trouble quite a few times (almost killed on the highway in a thunderstorm one time.) All pads are in really good shape…I mean, they ought to be considering they don’t engage properly!

One thing to note is ahissing sound when I turn off the engine, approximately in the area of the brake booster, which I was told by a different garage a few years ago was a vacuum thing. Duh. That's pretty obvious but I don’t know if ithas anything to do withthe brake booster. For about a month now I've been set on replacing the brake booster once I had the money but now that I read that tech update, I'm having second thoughts.

So what does this sound like? Air in the lines? Faulty seals on the MC? Faulty check valve on the brake booster vacuum hose? Some sort of ancient Mayan or Voodoo curse??

 

If you are losing brake fluid, then check a couple places. Look at the master cylinder (it's the thing that you fill up with brake fluid) and see if there is any brake fluid leaking onto the brake booster. You may see paint peeling from below where the master cylinder bolts to the brake booster.
Take off each wheel and check the brake lines for fluid loss.
Finally, take off the rear drum and check if there is fluid leaking from the wheel cylinders.

The spongy feel may be that the brake lines weren't properly bled.
You may want to replace the brake master cylinder, not the brake booster.