[s-cars] Brake sytem question

[derocco_16v at comcast.net]

Hi all, my '95 S6 has been experiencing an odd behavior, which I hope you'll help me understand to address; whenever the vehicle is tilted (like when approaching steep driveways at the angle) I can see the brake light come on for a a second; then all goes back to normal. I keep a close eye on brake fluid level and have not notice any leaks at all. What should be my next step in troubleshooting this issue? 
Thanks. 

Martin, 

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'95 UrS6 
'87 16v rocco- GONE 
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