okay, im gonna try this one more time, no response on last post.
i have an 07,1500 classic 2-whl. dr. w-a 4.3 an 5spd.od.

i would like a step by step process on draining an flushing the cooling system. now i have the generous motors shop manuals, an to me it seems a touch fuzzy. maybe there is a less complicated process. i know i have to use dex-cool so that isnt a ?.

 

I don't know about the new ones, but heres what I did on my 98.

Unhook passenger side lower hose from radiator. Unhook one of the hoses from the heater core. Then hook a garden hose up to the heater hose and run it until you see only clear liquid come out the other unhooked hose.

Because I knew that my total fluid capacity was 16 quarts and my radiator capacity was 8 quarts, I simply left the water that was left in the system in there, then filled the radiator with 8 quarts of straight antifreeze. After a few days of adding 50/50 whenever I needed it, I was left with a perfect 50/50 ratio.

As I said, this may be different for your truck as mine is much older, but this is what I did. Could I ask why exactly you want to flush the coolant? I usually don't worry about it, but in my case I had a cracked radiator so I wasn't given much of a choice.

 

thanks for the reply 92chevysilvy.
your process is pretty much along the line that i have been tempted to follow, but i just wanted another opinion. only thing i might add is i figured on taking out the block plugs to make sure i was getting clean water while flushing before i added the antifreeze
now as to why i want to change the antifreeze, im just a maintainance.freak. i got the truck in feb. w/45000 miles an i dont know what has been serviced, so im doing anything that is suspicious so i can have a record. i know the manual says 150,000 miles for a change but im not buying into that at all. i have always been fussy about service on my pieces. thanks again for your helpful reply.

 

If you wanna be fully sure, run a flush in the system for bout 3 days, then do this process he mentioned above. This will help clean out all the gunk, if any, in the system. Also drain the radiator fully from the pit ****. The heavy stuff will collect in the lowest point of the vehicle, the bottom of the radiator.

 

Crap I forgot about the petcock! Good call Ruffneck... I replaced my radiator so I didn't have to worry about it, so I guess I forgot to mention it.

Anyways, good luck with the project and hopefully all goes well!

 

thanks for the reply guys.
now according the the GM manual it says not to add any flushes to the system, which im gonna follow cause the antifreeze looks pretty clean anyway,probably there is no need even to do this. but i have to know what has been done an when.also it says to drain the system is to remove the lower radiator hose an drain into a container, which should be interesting, cause there is no pitcock on the bottom either,an i cant see draining the whole system by removing the lower hose, thats why i came up with the idea to remove the block drain plugs, im just trying to come up with a more simple process than what is in the goofy manual which with you guys help i think i have it down pat. i just want to add that the people who design these pieces should also have to fix them!

 

I thought my coolant looked pretty clean too, but when I drained it from the bottom of the radiator, quite a bit of gunk came out. So may I suggest taking the radiator out and tip drain it to be safe.

 

thanks for the input. maybe when i take the bottom hose off i can feel inside the bottom for junk, if not i will take the radiator off, thats not a major offense anyway. i know the radiator is the lowest part of the cooling system so it will collect any junk first. thanks again.

 

There's a reason GM tells you not to flush the radiator. Most city water has minerals that will cause intermal corrosion and rust in your engine and wear on your water pump.Here in S. Ca. the water is so bad that it eats the plumbing fixtures right off of the sink.I would not mess with the freeze plugs unless one is bad. Take the cap off of the reservoir and then just pull the bottom hose and catch the fluid with a large pan. To make this a litter easier, if you don't already have one, get yourself a set of hose clamp pliers to handle the hose clamp. After that mix your Antifreeze 50% with Distilled water, or you can buy it already mixed for about twice the price. Either way do not use water out of the hose.I did this to my 5.3 around 45k only because climbing some steap grades pulling my trailer, 6650 lbs. the temp moved up to 210-212 it has always run bellow this before around 208-209 on the guage. I also did an adjustment with my Super-chip to have the fan come on sooner.Just finished another trip, and comming up on 84k on the truck and all is fine.jvp