Coolant drain plug has no screw in it?!?!!?

[woodbutcher]

The way that I have always drained and flushed my cooling systems is this.Drain through the drain cock.Remove the Upper hose from the radiator.Put a garden hose in the radiator fill opening.Turn on hose with the engine running.Run water through hose just fast enough to keep radiator full.When it runs clean,open drain cock and let out enough water to add a container of heavy duty radiator and block flush.I generally do this in the morning so that I can run the flush all day.I let it set in the cooling system over night.Run the next morning till it is at operating temp.
Drain and refill with a 50/50 mix of antifreeze and water.
Leo

 

[Anonymous]

so leo you didn't back flush did you??

you like front flushed?

is it possible to back flush the engine while it is on cuz of the water pump pumping it the other way??

what is better front flushing or back flushing or are they about the same??

Thanks Leo

-Mr.T

 

[woodbutcher]

The only time that any of my vehicles have been back flushed was at a radiator shop when I had to install a new radiator because of non repairable damage.You can`t back flush a cooling system when the engine is running according to the people at the radiator shops that I have done business with.
Leo

 

[66 Fastback]

I have the Prestone Flush kits installed. The instructions with those say you run the engine and that is how I have always done it. Those kits do not back-flush. As Leo said, with the engine running, the water pump is going to force water one direction. I warm up the car, drain and refill with water and some flush additive which nowadays is mainly a surfactant. I warm it up again and drain. Once the engine is has cooled down, hook up the garden hose and install the flow neck in the radiator. I start the car and flush the engine until clean.
Then with the water still flowing or not, I pull the block plugs and open radiator drain. Continue flushing those and then maybe even run the car some more.
I am careful to not introduce cold water from the hose into a hot engine and risk cracking something.
Doug

 

[AZstang66]

He's right, some of them DO have left-handed threads. Mine does.
Also, you have to watch out because for instance my one has one of those lame square head bolts that seal the drain hole. And whoever the bright engineer was that decded it was a good idea made it a 5/16" sized head.
Needless to say, the spanner rounded and I had to rip out the vice grips...