My 85 380 se has the fuel pump/filter in that area. To test for brake fluid I would put newspapers or cardboard in the area and press hard on the brake then look for a wet spot. If none then I would start the car for a minute or 2 and look for wet spot. If neither, I would drive to a mech.

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85 300 SD ~ 115K
82 500 SEC Euro ??K
78 450SL 164K