What is it?

[cycleguy55]

Originally Posted by Gjesion

I think it is a coolant overflow tank. The large hose comes the neck of the fill tank above cap seal. The small hose goes overboard. The car (Superformance) is new to me and each time I drive there is coolant leaking from the small hose. I looked on the Mr. Gasket website and found nothing like it. It is running a 460 and was built in 2000. Any ideas of exactly what it is and how it should function would be greatly appreciated!

Regards,
Jerry

P. S. the coolant fill tank is filled to ~ 3/4" below the opening flange, and after looking underneath, it is puking out fluid as I drive.

I can't confirm it, but I suspect it's a coolant recovery system. When the coolant in your engine and 'fill tank' (likely an expansion tank - post a photo) expands it expels the additional fluid through the larger hose into the coolant recovery tank. When that gets too full it dumps the excess through the smaller hose and, based upon what you wrote, onto the ground.

As the engine cools, it will draw the coolant from the coolant recovery tank back into the expansion tank. Coolant should be added to the recovery tank if necessary, not the expansion tank.

[Gjesion]

Brian,
It is even more strange. There is another large hose that exits the Mr. Gasket tank which is another vent? It goes down to the frame and is open. Attached is a pic of the coolant fill tank. My assumption is the other smaller hose goes to the radiator. I am puzzled by all of this......

By the way, how much coolant should be in the fill tank?? It is currently filled to 3/4" from the bottom of the neck.

Regards,
Jerry

[patrickt]

If that's a homemade coolant recovery system it's possible that the creator did not use a recovery type cap. A lot of people don't know that there are two types of caps. See this thread: Overflow Tank question and references to the Putnam Suck Test to distinguish between the two.