Pretty sure the heater hoses are  5/8" id.

Thanks, what about the male flare to the newer heat valve?

I have previously used a remote heater valve, is this the one that you have?

if so, you will find the four outlets are designed for the standard 5/8 inch heater hose. I am unclear as to where the barbed fitting you are talking about is located.

if the connection you are talking about is the connection to the under-car heater pipes, they are also designed for 5/8 inch heater hose and incorporate a full circumference raised bead.

although not cheap, I would encourage you to look into using silicone hose for your heater installation. Very flexible and durable, be sure to scuff the inside of the hose and use the correct T-bolt clamps.

I don’t know if I touched on your problem. Please give us more information to include location, etc. and we will try to troubleshoot from afar.

Larry

You use the term “flare” fitting but a flare fitting is typically for HVAC refrigerant lines. 🤷‍♂️

Can you please post a photo of the fitting in question on the Wilkinson evaporator core?

Larry

The threads for the old valve appear to be correct but the new valve must have a male flare to seal

does anyone know what thread size this is?
outside diameter looks like 5/8 but would it be metric?

Thank you for the photos. Worth far more than 1000 words.

from the photos I think you have a 3/8 inch aluminum line. Or it could be 1/2 inch. Because the evaporators are fabricated here in California I suspect they are standard number six and number eight flare fittings. I don’t believe metric comes into the equation.

you might have to hunt to find one with 5/8 inch barb, or use more than one fitting, combined to create what you need

Thanks! I'll give it a shot!

Just call Steve Wilkinson. If he doesn’t have the adapter you need, he’ll surely be able to tell you exactly what is required.

David

did that first, posted this after