2006 Freightliner Coronado Coolant reservoir black

Your hosed. You have one of a number of potential problems.
Start with a test of the coolant for the contaminant.
Then work from there.

could be something simple, then you could be looking at a full inframe.
Bottom line, coolant should not be contaminated or black

 

Sounds like exhaust/compression. It must be pushing coolant out.

 

I'm no mechanic, but I would guess you have lost a head gasket. There is a slim chance that it could be your compressor, but if it were me I would plan to get it home or to a good shop that you are comfortable with sooner rather than later.

 

Any pics? As far as i understand a leaking oil cooler will put oil into the coolant tank. But id imagine that would look like milkshake rather than straight black.. what does it smell like ? What engine u got?

 

Maybe @Big Road Skateboard or @Rideandrepair have some better ideas

 

Pics would definitely give anybody with knowledge a better idea. Maybe draw a bit of coolant into a clear glass and get a pic also.

Where is the coolant coming out of the reservoir at? Yes, If you've got time you could pull a sample and have it tested, but there's really only a few things it could be.