Nope. The drain plug is near impossible to get to and I've read that even if you can get it, that there is a high probability it will break.
Just remove the lower radiator hose. It's still tight, but very do-able.

 

go at it from the top or bottom?

 

Bottom, its on the bottom of the radiator on the passenger side...goes from the radiator to the water pump, loosen the clamp on the radiator and let it drain...if u do decide to try the drain plug, its located on the driver side of the radiator and its a size 13mm socket, you need the long socket, but as stated before these do tend to break a lot, since the plastic is old and around heat from the exhaust and what not it gets weak and breaks easily. Def just remove the bottom hose, easiest way to do it! Not hard at all

 

Pressurize that coolant overflow tank!!

I read some of the posts on this subject and found a easy and clean way to flush the coolant.

If you have a shop vac, reverse the hose to blow air (instead of sucking air) and place the hose right on top of the coolant overflow tank with the cap removed.

You will have to remove the coolant hose going from the radiator to the coolant overflow tank at the tank side. Pinch the clamp with a set of vice grips and slide the hose away from the tank. Now put that hose into a clear gallon jug and attach that jug securely to the car with clamps or wire.

You will now have a open nipple on the coolant overflow tank from which you removed the hose. Take your shop vac hose and place it on top of the tank where the cap was (fits perfectly) and turn on the shop vac. Don't forget to plug the nipple with your other hand.

Your coolant will be completely flushed in a few minutes!

Hope this helps someone out there!

 

I don't see how that Shop Vac method would get out any fluid except what's in the expansion tank, since the tank is the high point of the system.

 

You blow air into the expansion tank, it goes into the head and pushes all the coolant out through the top of the radiator (the small hose that runs to the expansion tank).

 

The same can be done with the disconnect of the heater core loop.

It has always baffled me why so many suggestions are out there to flush with a garden hose, introducing mineral compounds, and for those on the grid, chlorine and chloramines in the water.

Air will purge the system and not leave anything behind.

Bleed the air out properly, and always use distilled or distilled/de-ionized water for mixing with say Pentosin or DexCool in later models.

Agree on removing the lower hose. Skip the troublesome petcock. Even if you don't damage it, you could have a stubborn O-ring just waiting to give you fits going back in or even one that decides to split.

 

The petcock is on the driver's side of the radiator at the bottom, but facing towards the engine. It is somewhat difficult to get to but worked fine for me.