Heater pipe to heater core connection

[live4theking]

In other threads you will see that I've been working on my heart box. I have it installed in the car, but have a leak when I slide the lever to warm. The leak is between the heater pipes that connect to the heater core. See pictures below.

heater pipes

Heater core connections.
Because this is an AC car it has a dual core. The lower tube in the second picture is the inlet which is an "h" valve that controls whether coolant goes to one or both cores. The upper is the return to the engine.

Each tube gets a o ring to seal the connection. The bottom connection leaks like a sieve. I'm sure that I've tried the o ring that came with it and numerous others.

I was told that because I glass bead blasted the pipes and inside the connections I probably took "meat" off the inside causing them to not seal. I bought another box and took the pipes off it. To me it looked like someone used a lot of blue permetex on it years ago.

I almost forgot. As a last ditch effort I used Ultra Black gasket maker Saturday evening. I waited more than the 24 hours it says and it still leaked.

I've got some o rings coming from a local company a few towns over and I may order some from Mcmaster.com as well.

Has anyone else had this issue? How did you get it to seal up?

 

[live4theking]

My understanding is this set up was used on cars pre 69. I'm working on my 68 NYER.

 

[volksworld]

have you tried changing the h valve?

 

[live4theking]

have you tried changing the h valve?

The "h" valve is brand new, but believe me I haven't ruled it out as being the culprit. At this point it will be after Carlisle before I would pull the box from under the dash and remove the "h" valve.

 

[volksworld]

bought a new h valve for mine cause i was afraid of the shaft leaking after 50 years...still a couple weeks away from putting the box back in so definitely interested in what you find...be my luck to replace a valve that wasnt leaking for a new one that will

 

[live4theking]

bought a new h valve for mine cause i was afraid of the shaft leaking after 50 years...still a couple weeks away from putting the box back in so definitely interested in what you find...be my luck to replace a valve that wasnt leaking for a new one that will

Yesterday at lunch I ran over to the local radiator shop to ask them about the situation. I explained to the owner what was happening and he simply says "I think it is leaking behind the o-ring." I said to him to make sure I'm understanding what you are saying is you think it is leaking on the "h" valve where the collar is soldered on? He said yes. (Where the arrow is pointing in the picture below.) (That is not the brand of "h" valve I bought. Best picture I could grab from the net.) He offered to pressure test it when I remove it from the car again.

I just received some "softer" o-rings today so I may try them tonight or tomorrow. I need to put my backhoe back together first. If it still leaks I'm bypassing the heater core and I'll take it apart again after Carlisle.

 

[volksworld]

the original air group/classic air valve you have pictured is the one i bought...

 

[live4theking]

The softer o-rings did no good. The heater core is bypassed for the time being. The box will be removed again after Carlisle. I'll have the local shop pressure test the valve and other components to see where the leak is coming from.

 

[Ripinator]

The softer o-rings did no good. The heater core is bypassed for the time being. The box will be removed again after Carlisle. I'll have the local shop pressure test the valve and other components to see where the leak is coming from.

Bummer, John. Bummer. . .