Packard Forum Index » Pre-War (1899-1942)

I was flushing the cooling system on my 1941 Packard 120, and the engine block drain plug is stuck.
I do not want to completely round off the square plug head or break the plug.
Is there some method(s) to free the plug?
Or, is there another way to drain or flush the block without removing this plug?
Thank you, in advance, for any thoughts or advice.
Jim

The later engines replaced that plug with a drain cock. You may try some targeted heat on the plug head.

One of those inductive heater things would work good.

Thank you.
I will try your suggestion.
Jim

If I can not remove the plug, is there another way alternate method to flush the block?

Quote:

No, not adequately. If just heat didn't work, try melting some candle wax into the threads next time you heat it up. Or you could let it soak for several days, liberally coating with PB blaster or some other lubricant. Don't worry about rounding off the plug, once you get it out, it can be replaced with a drain petcock or another plug, as it is just pipe thread. I would be careful not to break the plug though, because that would be much more difficult to remove.

Thanks you for suggestions, everyone!
I was able to get the plug loose.
Jim

JRB, you might install a brass stand off in place of another simple plug. Not one of Packard's smarter moves, having coolant pouring from the block near the oil dipstick.

While running a garden hose into the top of the radiator with the radiator petcock closed so everything comes out your now freed rear block plug, poke around far as you can with a piece of welding rod or straightened clothes hangar, then open your radiator petcock, let that drain. Fill cooling system with water, a pint or two of kerosene, and a couple pounds of Arm & Hammer Washing Soda (not baking soda). Drive the car 18-20 miles at least. Then open the rear drain plug again. Once the engine's cooled down, run warm or tepid--not cold water-- from your hose, perhaps when it's been in the sun on a hot day, repeat the welding rod/clothes hangar routine. Do this until just clean water emerges. Then run the hose with just the radiator petcock open 'til clean water only comes out.

If your part of South Carolina never sees two consecutive nights of a hard freeze--- 30 or below-- with your car garaged with no wind chill factor, avoid antifreeze like the plague.
Take some big plastic jugs to Sprouts (are they out there?) or Whole Foods and fill with reverse osmosis water. Use only that and either No-Rosion Corrosion Inhibitor or Redline Water Water. No "water pump lubricant" or other bolshoi. Never use distilled water, which is ion hungry, leaching minerals like lead, copper, etc. from your radiator.

If you order No-Rosion, tell Jay Ross that Mike, '47 Super Clipper, Walnut Creek, CA referred you. For everything you need to know on cooling system health:

norosion.com/tech_coolant.htm