Draining 1960 radiator and block

[Joe M.]

I drained the radiator last night so that it can be removed. The overflow tube rotted out of the filler neck. A little over 2 gallons was all that came out and that leaves a little under 2 gallons that I assume is in the engine, heater hoses and heater core.

Is there a way to use compressed air to force out additional fluid? I will not remove the freeze plugs.

[William C.]

Re: Draining 1960 radiator and block

There is a threaded plug just above the pan rail that can be pulled to drain the block (one each side) about the center of the engine.

[Joe M.]

Re: Draining 1960 radiator and block

Thanks Bill. Sounds easy enough. I can picture a stream of green fluid shooting out of the block as the plug comes out.

[William C.]

Re: Draining 1960 radiator and block

Only if you are fortunate enough to have a block that is relatively clean on the inside!

[Joe M.]

Re: Draining 1960 radiator and block

Engine was rebuilt 8 years ago. The fluid that drained out of the radiator looked like fresh antifreeze. I used distilled water 8 years ago; hoping that would make a difference.

[Joe M.]

Re: Draining 1960 radiator and block

There is no threaded plug on either side of my engine block; just above the oil pan; center of the engine. I drained 10 quarts and that is 7 remaining. Unless someone has a better idea, I am not going to worry about completely purging the block. I did drain the heater core. I was able to get the overflow tube soldered back for $25. I like inexpensive Corvette repairs!

[John H.]

Re: Draining 1960 radiator and block

There is no threaded plug on either side of my engine block; just above the oil pan; center of the engine.

Joe -

If you don't have those plugs, you have a "one of one" block.

[Bert L.]

Re: Draining 1960 radiator and block

Yes Joe, look a little closer you will find them, they must be there. Once you find them hope you can take them out without too great of a hassle!

Bert

[John F.]

Re: Draining 1960 radiator and block

Joe, they look like this. One in front of the starter and one on the driver's side.

[Joe M.]

Re: Draining 1960 radiator and block

I appreciate all of the help and the photos. I will look again on Saturday.

[Joe M.]

Re: Draining 1960 radiator and block

Apparently, when my engine was rebuilt, the plugs were installed inside the block. The threaded holes are present on both sides of the block, but no external plug. I will ask my mechanic why he chooses to install the plugs on the inside of the block.

[Jim T.]

Re: Draining 1960 radiator and block

All my Corvettes have the block drains and the procedure to remove them to change the coolant is mentioned in the owner manuals and service manuals. Get about 2 quarts coolant from each side block drain location. On my 96 LT4 I even remove the two knock sensors which screw into the block drains. Good way to remove trapped sediment. Wonder how much trapped sediment it takes to affect engine cooling?

[Timothy B.]

Re: Draining 1960 radiator and block

Joe,

The mechanic could have used allen wrench type plugs and they are screwed up inside the threads which is why you may see tyhreads showing. Regardless, those plugs were installed and should come out as it's a important step in proper coolant flush.

[Donald H.]

Re: Draining 1960 radiator and block

Joe, Here's another picture. I believe the plugs are 9/16" NPT with square head. A good way to really flush the block is to remove these plugs and the thermostat housing and run water throught the thermostat housing. I did this on my 66 when I got it and got a lot of crud out.

[John F.]

Re: Draining 1960 radiator and block

After pulling the plug and running water down thru the thermostat housing, I also run a piece of wire or coat hangar up the hole to break any crud loose.