Plastic box under manifold next to head 1990 740

Deeseven · Post by **Deeseven** » 08 Sep 2012, 15:28

I have been wrenching on my 740 gl (1990) all morning to fix what turned out to be a split hose that I could not reach under the manifold going directly into the block. I am pretty sure this has to do with the heater core. When I finally removed the manifold, I found a plastic box with a single 2 inch hose leading to no where. I am baffled right now on where the short hose goes, and what this box looking thing is and what it does. Thank you for reading all of you guys have been a big help over these diy years.

Deeseven · Post by **Deeseven** » 08 Sep 2012, 23:25

PCV valve?

Fred760DC · Post by **Fred760DC** » 17 Oct 2012, 19:33

Flame trap. Pulls oil fumes off from under the valve cover, condenses it and drips it into the oil pan. In the end of the hose is the plastic screen called a flame trap. Clean this every year or so. You don't want pressure under the cover As the hoses get stiff and brittle and hard to fit, get the kit from FCP.