Has anyone had this problem or have a suggestion? I just installed a new heater core in my 2000 Silverado. I then pushed a Dorman 800-409 3/4" tube to 5/8" hose quick disconnect heater hose fitting onto the outlet(?) tube and quickly felt the inner seals of that fitting become tight on the tube. Being very concerned not to damage the heater core, I tried to twist the fitting and push it to the lip and click in place. Now the fitting seems to be stuck somewhere short of the intended position. Some in-town driving has not blown the fitting off. I suppose that would require more pressure than the cooling system creates, but what would you do? Would you trust the fitting to stay on the heater core? Would you disconnect the hose when the engine is still warm (but safe to handle) and try to move the fitting? Would you cut the fitting carefully and remove it and replace it with another brand? Here's another thing I don't get -- it turns out that the tubes on the new heater core are not the same size. The side I believe to be the inlet is 3/4", while this one I'm dealing with is 5/8". How could a 3/4" fitting, which is supposed to be the correct match for the Silverado, get hung up on a smaller size tube?
Brand new quick disconnect fitting is stuck on heater core
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Remember it's aftermarket and may not sit as far back as the oem. I would probably try and use a disconnect tool first to get it off and compare it to the old one. If that fails then yes I would cut it off and replace it for ease of mind.
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well you said it the heater core tubes are not of the same size as old so now this problem. these quick disconnects were used to increase speed of factory fabrication /reduce time .. many have had OEM disconnects just blow off with the plastic parts. so rather then get aftermarket fittings they just double clamped the hoses to the heater core.
I have always recommended never to mess with those hose fittings when flushing the heater core.. the use of drinking water is not proper even though GM says its what to use.. distilled water is required because it does not have corrosive chemicals and metals in it .
replacement of the core is a big PITA.. don't want to do that again so use a dremel tool to carefully cut of that connector ..
you can then use a sealer to coat the core tube and then clamp on the hose....
I have always recommended never to mess with those hose fittings when flushing the heater core.. the use of drinking water is not proper even though GM says its what to use.. distilled water is required because it does not have corrosive chemicals and metals in it .
replacement of the core is a big PITA.. don't want to do that again so use a dremel tool to carefully cut of that connector ..
you can then use a sealer to coat the core tube and then clamp on the hose....
The disconnect tool didn't budge this particular fitting. It seems to be wedged on too tightly and isn't seated in the first place.
Okay, thanks everyone very much. I will remove the fitting. j cat, what kind of sealer are you referring to?
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He is probably thinking some sort of rtv. You'll probably be just fine with hose clamps only.
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I would use permatex formagasket black very similar to perfect seal used on boat engines/out drives .. you want a surface that will be coated with a product that will flex with the temp changes and add more resistance to blow off ...
the other reason this is also used is so that the metal portion will not corrode .. [boats]
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