Brake light turns red under hard braking in 1990cq

["John S. Taylor" <#jstaylor@ix.netcom.com>]

Sorry if you already looked at this but I had same symptom on my 87 
5KCSTQW. Turns out the brake reservoir is two pieces -- a metal base and 
a plastic reservoir. The plastic reservoir is anchored to the metal base 
with two seals which, after 10 years, gave way. The plastic reservoir 
was held in place only by gravity. To test this, push down on the front 
of the reservoir. If it rocks, the seals have gone. Because of the 
design of the metal base, the fluid never reached a critically low 
level. However, anytime I went down hill or braked hard, the plastic 
reservoir would rock forward.

Dealer price to repair this was less than $100 to replace the seals. 

Hope this helps

   jst
87 5KCSTQW
Reston VA