C2 - Engine Block Coolant Drain Plug

[John L.]

Looking at the underside of my original L/72 '66 Block, I located the Coolant Drain Plug on the passenger side above the starter motor but could not locate the Plug on the drivers side of the Block, did this Block only come with one Drain Plug? If not, where would the passenger side Plug be located? Thanks for your feedback.

[Bob R.]

Re: C2 - Engine Block Coolant Drain Plug

It should be right under the lower shielding on the drivers side similar to the location of the passengers side. You might have to move or look behind the lower shielding.

[Joe L.]

Re: C2 - Engine Block Coolant Drain Plug

It should be right under the lower shielding on the drivers side similar to the location of the passengers side. You might have to move or look behind the lower shielding.

Bob and John------


No shielding on a big block. However, there should be a plug on the driver side, lower center.

By the way, finding the plugs is the easy part. But, if you need to remove them (e.g. for a complete coolant system draining), that's the hard part. They're almost always rust-seized.

[Bob W.]

Re: C2 - Engine Block Coolant Drain Plug

John Joe is right they can be tough to remove go slow.

[Duke W.]

Re: C2 - Engine Block Coolant Drain Plug

Use a six point socket and half-inch drive breaker bar to shock them loose. Use pipe joint compound on the threads when you reinstall and only go "snug". There are no torque specs than I am aware of for NPT. The general rule is tighten just enough for a leak free joint. If you want to use a torque wrench, don't go more than about 10 lb-ft. Most people over-torque them. Pipe joint compound will help seal and prevent seizing while acting like a thread lock compound to keep them from coming loose.

Pipe joint compound should be available at any hardware store or home center. It's formulated to seal hot and cold water and steam pipe NPT.

Duke

[James W.]

Re: C2 - Engine Block Coolant Drain Plug

I did this very thing last night on a '65 L78. The driver's side plug is located directly behind the exhaust manifold and is somewhat hard to get a 9/16" open-end or box-end wrench on. I actually had take the oil filter canister off to get enough room to get the wrench on the plug and to be able to get room enough to move the wrench to loosen and tighten the plug. Went back just as others have said using pipe joint sealant tighten it snug tight. The hardest part is holding your tongue right to get the driver's side plug threaded back into the block due to limited space for fingers. The passenger's side is a piece of cake.


Regards,

James West