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Black fluid leak under driver door

My brother owns a 1993 Lincoln Towncar and it is leaking a black fluid under the driver door. It has been unusually hot this summer and we are wondering if it could be his rust proofing.

Sure can, is that the kind of rustproofing material he had put on? Friend had that happen to his TR-7, except it didn’t leak on the ground, it leaked into the trunk, onto his nice sports coat.

Some years back, a friend of mine noticed a black fluid leaking at the rear of his Oldsmobile Omega (a front wheel drive car). This happened Christmas day when he and his family were leaving for a trip to visit relatives. The only mechanic he could reach by telephone suggested it might be a rear strut, but there was no way he could get a replacement strut at Christmas. The family piled into their second car, a Ford Pinto, and made the trip. When the got home, they figured out the problem. Their teenage son had left a coke in the trunk. It has frozen and broken the container. While the car was inside the garage, the coke thawed and the fluid ran out a drain hole in the trunk. You might check underthe seat of your town car and see if some soft drink spilled under there.

This could also be brake fluid so it would be a good idea to check the fluid resevoir.

Good thought. The brake fluid might be dissolving the undercoat material and giving it a black color. I had a fuel tank leak once and the gasoline dissolved the undercoat on the gas tank and residue on the garage floor was black.

Don’t the fuel lines pass under the drivers door and as mentioned above fuel leak.

Typically they’ll pass through the center tunnel, but in this case it’s a really really good idea to put the car on a lift ASAP and see what can be seen.