Fixnstuff
Full Access Member
If by 'metal tube' you mean the part where the hose connects on the radiator, it doesn't look like a metal tube. It's steel and it appears to be very solid. I'll show a picture of it here. This is the replacement radiator I put in my truck. I got it from a 91 or 92 F350 and it was not the original so it probably wasn't more than 5-10 years old.
I have a C-6 so I just blocked it off with a short piece of 5/8 heater hose with a bolt pushed into the open end after I cut off the threaded section of of the bolt leaving just the smooth shank under the bolt head, some sealant and a small hose clamp.
Later I plan to change the fitting or better, just drill it out to a very slightly larger diameter hole and use if for a coolant filter set up. I don't want to enlarge it much at all or it will be robbing too much coolant from the return hose to the water pump which could result in some water pump cavitation.
On the subject of coolant filter installations, they should be installed in parallel and NOT in series with the return heater hose to the water pump BECAUSE when the filter begins to plug up it will reduce or block the coolant returning to the top of the water pump, creating situation where water pump cavitation can occur.
Whether a filter can be installed in-line wih the heater hose return line to the pump (or not) has been much argued but from my analyses, parallel is best, because: The water pump impeller is also pulling coolant from that return hose from the heater core and if the flow in that hose becomes obstructed or reduced enough by a clogging filter, the pump impeller will pull some vacuum at that location and cause, causing void empty of coolant which can result in cavitation on the vanes of the pump impeller and adjacent surfaces like the backing plate.
I couple of years ago, member IDiot From California posted a photo of a water pump backing plate with serious cavitation pits wondering what could have caused it. I wanted very much to ask some questions in that topic (a medical condition at the time prevented me from doing so) and bring up this coolant filter plumbing controversy, (in-line or parallel installation) and suggest that as one possibility for the cavitation damage seen. Also that can happen in a cooling system that is quite low on coolant.
OK, here are two photos for you. I think the second one is actually more important.
E4OD Radiator Heater Hose Fitting: A lot more fluid runs through that little hole than you might think so when you disconnect the hose from the radiator fluid will run in a stream to the ground so either have your new hose or plug ready to put on or put a pan under it
The next photo is of the saturated insulation under a leaking overflow reservoir. See notes below:
You can't see into any of that area without removing the battery, the reservoir and maybe the battery tray if you want to clean it up and paint it (which I did). Since you can't find a leak anywhere else THIS is where I would look.
I have a C-6 so I just blocked it off with a short piece of 5/8 heater hose with a bolt pushed into the open end after I cut off the threaded section of of the bolt leaving just the smooth shank under the bolt head, some sealant and a small hose clamp.
Later I plan to change the fitting or better, just drill it out to a very slightly larger diameter hole and use if for a coolant filter set up. I don't want to enlarge it much at all or it will be robbing too much coolant from the return hose to the water pump which could result in some water pump cavitation.
On the subject of coolant filter installations, they should be installed in parallel and NOT in series with the return heater hose to the water pump BECAUSE when the filter begins to plug up it will reduce or block the coolant returning to the top of the water pump, creating situation where water pump cavitation can occur.
Whether a filter can be installed in-line wih the heater hose return line to the pump (or not) has been much argued but from my analyses, parallel is best, because: The water pump impeller is also pulling coolant from that return hose from the heater core and if the flow in that hose becomes obstructed or reduced enough by a clogging filter, the pump impeller will pull some vacuum at that location and cause, causing void empty of coolant which can result in cavitation on the vanes of the pump impeller and adjacent surfaces like the backing plate.
I couple of years ago, member IDiot From California posted a photo of a water pump backing plate with serious cavitation pits wondering what could have caused it. I wanted very much to ask some questions in that topic (a medical condition at the time prevented me from doing so) and bring up this coolant filter plumbing controversy, (in-line or parallel installation) and suggest that as one possibility for the cavitation damage seen. Also that can happen in a cooling system that is quite low on coolant.
OK, here are two photos for you. I think the second one is actually more important.
E4OD Radiator Heater Hose Fitting: A lot more fluid runs through that little hole than you might think so when you disconnect the hose from the radiator fluid will run in a stream to the ground so either have your new hose or plug ready to put on or put a pan under it
You must be registered for see images attach
The next photo is of the saturated insulation under a leaking overflow reservoir. See notes below:
You must be registered for see images attach
That insulation is SOAKED. I was constantly loosing some coolant from the system. Every time I ran the truck and shut it off the pressure in the cooling system was relieved through the pressure cap by pushing coolant into the reservoir and that would leak out, saturate the insulation and run toward the front of the truck underneath the battery tray. You can't see into any of that area without removing the battery, the reservoir and maybe the battery tray if you want to clean it up and paint it (which I did). Since you can't find a leak anywhere else THIS is where I would look.