I recently tried to change coolant fluid in my 91 camaro with 305 TBI. I pull out one of the hoses from the radiator, ran the car for a while with heating on and then filled up the fluid. But surprisingly it took just about 2 gallons and capacity is about 4gallons right? So where is the rest of the old fluid? Is there some plug on the block of the engine or what? Im sorry to make new thread but i didnt have luck to find answer. The car is not overheating, so there is enough of fluid but i would like to flush the cooling system and make it right. Also, im not sure about the old fluid but i add about 3parts of coolant and just 1part of destilled water, so there is maybe more of coolant then water, thats not to good right? Thanks for help

 

I flush coolant by getting a hose, sticking it in to the rad, opening up all of the valves to let water out, and running the car for about 20 minutes at idle, that seemed to clean it out pretty well..

 

did you empty all the fluid from the engine itself cuz it might just be in there

 

I saw at K mart a little bit ago a 15-20 dollar flush kit. it would utilize the garden hose, and comes with instructions. seemed simple enough. btw, the mix should be between 50/50 to 70/30 antifreeze/water. good luck.

 

The other 2 gallons of coolant are still in the block.

There are 2 block drain plugs. They are in the sides of the block, halfway back, just above the oil pan rail. The knock sensor is the plug in the pass side, so once you find that, the driver's side one is just like it except it's just a plug.

No "flush kit" in the world will get the coolant out of the block, unless you take out those plugs.

Here's the pass side one on a block, with the plug/KS taken out....

 

Prestone used to make a flush kit for pretty cheap. They had an attachment that you had to splice into your heater hose. I used it on an older Chevy truck once and it did pretty good. After I flushed it, I just filled it up with water only and never had a problem out of it.

 

This is information scanned directly from the Haynes Techbook Automotive Heating & Air Conditioning book - this information is published - this is what I would do, people can argue with it if they want, but this is the right way to do it. Good luck.