Wheel cylinders fail one at a time.
You have to remember with these old brake systems is that if one wheel cylinder fails, the whole brake system fails because there is no dual master cylinder.
That is why the safety issue is brought up so much when these old brake systems are talked about. Today's traffic and speeds add a new dimension to safety issues that were not present 50-60 years ago. Also, safety may be over blown for you, but there are a lot of idiots out there who still need constant reminders...and most of them share the road with you.
