Two or four row radiator

[AirSpeed]

Originally Posted by luvbowties

Reckon it's for a temp sensor to regulate an electric fan system?
sam

That would be convieniant!
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[TBONE1964]

Is it threaded or soldered on. This is where the heater hose would go on a truck with A/C. If it is soldered on and is 5/8 in diameter then that is what it is for. Does it have a rubber cap over it?

If it is threaded, I am not 100% sure but like mentioned, it could be a place for a fan sensor.

[AirSpeed]

Originally Posted by TBONE1964

Is it threaded or soldered on. This is where the heater hose would go on a truck with A/C. If it is soldered on and is 5/8 in diameter then that is what it is for. Does it have a rubber cap over it?

If it is threaded, I am not 100% sure but like mentioned, it could be a place for a fan sensor.

It's soldered on and has a threaded
brass plug in it.
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[FirstOwner69]

Originally Posted by AirSpeed

Got my new radiator in this morning, fit like a glove! I have about six inches of clearance between the front of the fan to the radiator, my shroud actually covers the entire fan now, before it only covered about half of it.
The new four row radiator has an extra bung right below the cap and near the upper trans cooler line, it has a plug in it, any idea what it's for?
Thanks again for all the help guys!
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My 69 with A/C does not have/never had the heater hose connect to the radiator. I have only seen that on later trucks (72 and maybe 71). My 5/8" hose is attached to the right front of the intake. So, I believe it depends on what year your truck is. I see you have a 72. Where does your 5/8" heater hose connect now?

There are actually more differences from 69 to 72 than people realize.

[AirSpeed]

Originally Posted by FirstOwner69

My 69 with A/C does not have/never had the heater hose connect to the radiator. I have only seen that on later trucks (72 and maybe 71). My 5/8" hose is attached to the right front of the intake. So, I believe it depends on what year your truck is. I see you have a 72. Where does your 5/8" heater hose connect now?

There are actually more differences from 69 to 72 than people realize.

My heater hoses connect to the intake and the water pump. I was wondering if it my be for a more modern application with a remote tank kinda system but it wouldn't have tanks on the rad in that case. I'm leaning towards temp sending unit for fans which would be great since I'm looking to put election fans in it this summer.
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[FirstOwner69]

Originally Posted by AirSpeed

My heater hoses connect to the intake and the water pump. I was wondering if it my be for a more modern application with a remote tank kinda system but it wouldn't have tanks on the rad in that case. I'm leaning towards temp sending unit for fans which would be great since I'm looking to put election fans in it this summer.
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I did see a 72 Blazer in the junkyard last year that had the heater hose attached to the 4 row radiator where you describe. The radiator looked original (Harrison). I was thinking of grabbing it until I saw the bung for the hose. I'd say it should work for a temp sensor as long as the coolant is above it. However, there is always a air cushion at the tops of these radiators unless you are runnng a coolant recovery system. Since it is the coolant return line it may also be cooler than the rest of the coolant in the radiator. I'm sure there are experts here who can chime in.

[AirSpeed]

Originally Posted by FirstOwner69

I did see a 72 Blazer in the junkyard last year that had the heater hose attached to the 4 row radiator where you describe. The radiator looked original (Harrison). I was thinking of grabbing it until I saw the bung for the hose. I'd say it should work for a temp sensor as long as the coolant is above it. However, there is always a air cushion at the tops of these radiators unless you are runnng a coolant recovery system. Since it is the coolant return line it may also be cooler than the rest of the coolant in the radiator. I'm sure there are experts here who can chime in.

I do have a recovery tank, my old rad was always full to the top (except when a new leak would pop up!) this bung is about six inches down, it goes into a tube inside the tank, the tube is about 1" in diameter and open at the top. Ive never seen one like it. I was wondering how and where others mount a temp sending unit for fans, is it usually on the rad or the block? Thanks!
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[Lee H]

The 4 row in my 72 has one of those also, it held the heater hose return line for many years. It's about 3 inches below the top and is above the normal full level for my ride. I have it plugged off as I have the return line going to the water pump now.