"The Case of the Overzealous Car Wash "

It was the middle of February in Cleveland and temperatures had risen to a very un-wintry 60deg. What better day to wash the salt-encrusted Bus, which I use in my business.   No quickie hose-down; I gave it a thorough bath, especially the undercarriage and mechanical parts.

Overnight the temperature plummeted to 20ºF.   When I went out the next morning to begin my rounds, the Bus was sheathed in ice.  And, horror of horrors, although the engine started right up, the thing would not budge; it was as if it was frozen to the pavement. Well, almost.  The rear brake shoes were firmly frozen to the drums. Having experienced similar problems in the past, I knew that gentle rocking back and forth would break the tyrant's hold.  
Gentle rocking turned to violent rocking, with the beast rearing up on it's hind-quarters.    But break loose it did and soon I was on my way to the first job of the day.

As I reached the stop sign at the end of my street I found out how well dual circuit brakes on the Bus work - NOT !
No rear brakes at all and virtually no pedal left to apply the front discs!

Limping home, I yanked the rear drums off to assess the damage: Total.  
When the ice bond between shoe and drum broke, the result was a broken hydraulic wheel cylinder, bent brake shoe, broken adjusting screw, and shoes and drum soaked in brake fluid.

By the time the day was over I had shelled out about $100 in parts to rebuild the rear brakes (working outside in the frigid cold).

Moral: Leave well enough alone...