I have a slowly sinking brake pedal on my 142 - typical behavior associated with a bad master cylinder. So, I pulled the cylinder, opened it up, and found it to be like new inside. Then I checked my records and found that this is, in fact, an MC I installed new four years ago when I pretty much overhauled the whole brake system (hoses, rotors, pads, one new caliper, kits in the other three) and has about 25k miles on it. I find it hard to believe that the seals would go bad so soon. What do you think?

Furthermore, I can't find any leaks in the lines or at the calipers, and although the rotors are a bit rusty from the car not having been driven since April, caliper piston action appears to be normal. The booster, like on so many of these cars, is a bit fickle, i.e., at times, after starting up, it won't boost, but then, by the time the thermostat has opened, it comes on line and acts normal for the rest of the trip. I don't associate a fading pedal with a leaking booster, or should I? Anyone have an idea of what might be going on here?

Bob S.
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"62 PV544 (B20, M41), "71 142E, "93 240 Classic Wagon.