84 Radiator Drain Plug

[Thomas F.]

This is a plastic plug in a very difficult location to access. I finally was able to loosen this plug using a pair of pliers but it was very difficult to do. I finally had to fabricate a special tool to save time opening and closing this valve. Does anyone know if this plug comes completely out or just opens enough to let the water drain? I did not try to remove the plug entirely for fear of breaking something.

[Joe L.]

Re: 84 Radiator Drain Plug

This is a plastic plug in a very difficult location to access. I finally was able to loosen this plug using a pair of pliers but it was very difficult to do. I finally had to fabricate a special tool to save time opening and closing this valve. Does anyone know if this plug comes completely out or just opens enough to let the water drain? I did not try to remove the plug entirely for fear of breaking something.

Thomas------


It's not necessary to completely remove the draincock to drain the radiator. However, the draincock can be removed without breaking anything. Just back it out until the threads are completely disengaged. Then, you can pull it out. However, as I say, it's not necessary to do this to drain.

[Thomas F.]

Re: 84 Radiator Drain Plug

Joe, thank you very much for the information. I don't know what I would do if it wasn't people like yourself giving me a hand. Does this draincock completely remove all the water and antifreeze from the car or are there any other steps I need to take?

[Joe L.]

Re: 84 Radiator Drain Plug

Joe, thank you very much for the information. I don't know what I would do if it wasn't people like yourself giving me a hand. Does this draincock completely remove all the water and antifreeze from the car or are there any other steps I need to take?

Thomas------


No, simply draining the radiator leaves a LOT of coolant in the cooling system, mostly in the block. In fact, the radiator drain will only remove less than half the coolant in the system. To remove the rest you will need to remove the block drains which are located just above the oil pan rail, about the middle of the sides of the block. Your other option is to use a Flush and Fill kit, installing the tee in one of the heater hose lines with complete instructions provided with the kit. Make sure the flushed coolant does not go into the gutter or a storm drain.

Attached is a photo of the drain cock assembly used for your application. Note that this is a 3 piece assembly consisting of a stem, barrel, and rubber seal. If you unthread the stem completely from the barrel, you can pull the stem out. Usually, the barrel will remain in the radiator tank; you don't need to remove it. Although it's not necessary to even remove the stem, I have found that it sometimes helps to remove and clean it. To reinstall, press it in as far as it will go and then rotate it clockwise to screw it into the barrel.
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[Jim T.]

Re: 84 Radiator Drain Plug

Like Joe mentions, removing the block drains will drain a lot of coolant. If your 84 is configured like my 85, the passenger side block will have a knock sensor in place of the block drain plug. Your drivers side block drain will be a bolt, unless you have the optional cooling feature, in which I remove the hose going to what is mounted before the oil filter is attached.