1988 Hunter 28.5 top radiator hose filler neck

[inkunzi]

Hello my hunter 28.5 with 2gm20f engine has radiator hose coming out of heat exchanger at top of engine which then runs to a filler neck with pressure cap located in the battery compartment. Why can’t I just put the filler neck with cap at top of heat exchanger and eliminate this huge
1 3/8” radiator hose. I do have full access to top of engine. I made the top of engine compartment removable

 

[Ralph Johnstone]

What the %$^#&*#! has some PO done to this engine ?
Here is the original construction on top of the HEX :

I don't know what you'll find under the hose but I don't think a cap is going to go directly back on to what is remaining on top of the HEX.

You're definitely on the right track as the hose looks like it's on its last legs.

 

[Tally Ho]

Where does that hose terminate?

As @Ralph Johnstone said, someone Frankenstined your engine.

My 2GM20F looks a lot like Ralph’s (just not as clean).

Greg

 

[inkunzi]

Hello the hose exits the engine compartment to a filler neck with cap located in the battery compartment. It appears that this was done to allow access to fill the system since the engine compartment top is not removable. I went ahead and modified it so it slides out and I now have full access to top of the engine

 

[Claude L.-Auger]

I would remove the hose completely. You're right about the PO having done that because he could not figure out how to redo the compartment top like you did. BTW I had also done it on my 28.5 way back when. Once the hose is removed, look at Ralph's picture and if the hose was not simply collared on the rad cap assembly, then order the assembly and cap from a Yanmar dealer. If the assembly was not destroyed, then a cap will suffice. Good luck.