Where is the radiator drain cock?

[Peter G.]

Where is it? I have a 1973 LS4 with A/C and PS. I thought that all the original radiators had one? My radiator has been re-worked so maybe it's not there anymore?

I need to drain the coolant and add fresh coolant for the Winter Storage months ahead coming up soon?

Thanks in advance.

PS:I don't have a lift and have been only crawling under the front of the car looking for it. Maybe I need it on a lift to see it?

[Steven B.]

Re: Where is the radiator drain cock?

Friend had a C3 recored and it came back not with the drain cock but a brass bolt in its place on the pass. side. 'Harder to see or get to through that little hole. Maybe yours is there.

[Jim T.]

Re: Where is the radiator drain cock?

My original owner 70 came from the factory with a bolt/plug screwed into the elbow that is screwed into the bottom of the radiator on the passenger side.
I learned long time ago to put a wrench on the elbow to back up the effort required to remove the bolt/plug.
I don't reinstall it that tight.

[Joe L.]

Re: Where is the radiator drain cock?

Where is it? I have a 1973 LS4 with A/C and PS. I thought that all the original radiators had one? My radiator has been re-worked so maybe it's not there anymore?

I need to drain the coolant and add fresh coolant for the Winter Storage months ahead coming up soon?

Thanks in advance.

PS:I don't have a lift and have been only crawling under the front of the car looking for it. Maybe I need it on a lift to see it?

Peter----


There will definitely be a drain fitting on the lower surface of the right (passenger) side radiator tank. Whether a drain cock or plug is installed will depend upon what the radiator shop that serviced the radiator used.

Regardless of whether it's a drain cock or a plug, unless an elbow was installed (very unlikely), it will be difficult to get at.

[Kurt G.]

Re: Where is the radiator drain cock?

If I remember correctly the radiators did not come with a draincock. The radiators had a brass elbow with a brass bolt screwed in. My '72 was so tight I chose to remove the lower hose to drain the coolant rather than risk tearing up the radiator.

[Kenneth T.]

Re: Where is the radiator drain cock?

My 71 LS5 came with a brass plug and elbow. Do heed the advice of a second wrench to hold the elbow. I can say that the first time, it surprised me.

Ken

[Randall K.]

Re: Where is the radiator drain cock?

You may also want to take a peek at a recent post I started titled "72 BB radiator" from March 18. The feedback I received was that I'd be better off removing the lower hose instead of trying to remove the brass bolt.

Randy

[Robert R.]

Re: Where is the radiator drain cock?

Pete,

Yes, if your radiator is the original one, it does not have a drain cock.
The '73s introduced a new type of coolant recovery system and for some reason, the brass radiators had a plug vs a drain.
Would recommend removing the lower raditor hose to drain.
YES, a real pain and a bit messy, but the better solution.
Bob

[Terry M.]

Re: Where is the radiator drain cock?

From 1968-1972 copper-brass radiators had a drain at the bottom of the passenger side tank that was a right angle fitting with a brass hex-head plug. Sounds like 1973 was the same.

BTW: This thing is a real pain to get to, and as others have learned removing the lower radiator hose at the bottom of the passenger side tank is the lesser of the evils -- although not much lesser. If you find a drain cock there instead of the brass plug, Bubba has been there.

[Jack H.]

Re: Where is the radiator drain cock?

"...as others have learned removing the lower radiator hose at the bottom of the passenger side tank is the lesser of the evils"

Terry is DEAD NUTS on here, Peter! Walk around the Denver classic Corvette shops (Corvettes Only, Corvette City) and see how the shop mechanics work. You'll NEVER see a classic Corvette having coolant drained from the radiator pet cock! You WILL see the lower radiator hoses pulled with coolant falling into a catch bucket.

Why? Well all it takes is a faulty pet cock that's 'siezed' to fatigue fracture and then they're into a world of hurt to extract and replace the petcock. That's a 'rate buster' AWHECK episode!

Also, they've learned from experience that even if the pet cock DOES open and allow the radiator to drain, there's a good chance stray coolant system debris is going to 'stick' in the pet cock and keep it from fully re-closing...

[Peter G.]

Re: Where is the radiator drain cock?

Thanks for all the responses for this. Most everyone answered my next question. If I don't have a drain cock, what is the best way to drain the coolant?

So it looks like the lower radiator hose. It has the hose with the metal pipe.

[Kenneth T.]

Re: Where is the radiator drain cock?

Peter,

Remove the lower hose, safe and easy, no worries.
If you have tried it and see the flex on the radiator
it will make you cringe.

Ken