87CSTQ - Brake System Wierdness

[John Winkelman <digerati@worldnet.att.net>]

Had somthing strange happen yesterday. Maybe someone can tell me what
caused it.

I had been driving around town for maybe ten minutes when the brake
warning light came on with a beep--the one that (usually) indicates that
the pentosin reservoir level is low. It had been some time since I'd added
any, so I figured I'd top it up after I got home. About ten minutes later 
(I hadn't stopped after the warning light came on), all the brake
boost went away. Fortunately, I was within a block of my destination, so I
parked it and went on to my appointment. When I came back about 40 minutes
later, I popped the hood and found that the reservoir was less than a 1/4"
or so below the full line. However, there was some pentosin on the
top or the reservoir cap and some running down one side of the container.
It looked like some back pressure had blown some of the fluid out the top 
of the reservoir! When I started up the engine, the brake assist was back 
and no brake warning light. I've driven it for a day and a half now, but the
symptoms have not recurred. Any idea what happened? 

jw