I have a leak somehow where the 2 hoses join coming out of the heater core. I have checked and as far as I can tell, the leak is not coming from the hoses themselves I have photos below. I also have a code, the code about a small leak in the vacuum system, for the life of me I can not find it. I wonder if this is related. This photo shows the area I am talking about






This cap I am holding (I do not know the name) seems to be where the leak is coming from, underneath it.




The fluid is coming out from where I am pointing. It is a small amount and usually I have to move the cap and it starts coming out.




Any advice would be helpful Thank you

 

That is the bypass valve and assembly, the plastic cracks and leaks coolant, not uncommon, replace it

The grey vacuum line runs into the cab, when you select MAX AC, vacuum is sent to the bypass valve and it closes so no hot coolant runs thru the heater core inside the cab

The Temp control in the cab operates the Blend door in the cab, just FYI, no connection to the bypass valve in engine bay


Please post exact code numbers, not what you think it means
There is no "vacuum leak" code, could be EVAP code but we'll know when you post the code number

 

Thank you very much for the info. And yes, I screwed up earlier.. Evap not vacuum.... I will post the actual code later on when I get home. Thanks very much