Coolant drain/refill

DT10 · October 24, 2001

Greetings Bowtie fans,

Have any of you done a drain and refill on the coolant system? I have not worked with the sealed system type of cooling systems on my Silverado. I know everything is added via the overflow reservoir. Any cautions or words of experience are appreciated.

Thanks,

DT10

raventai · October 25, 2001

have not done it yet but I would think it would take a lot of heat/cool cycles to fill the whole system via the puke tank this would not be a good thing

I would remove the upper radiator hose and fill it almost full that way, and let the puke tank top it off

these have presurized tanks so maybe it is diffrent from the old style I am use to ???

raventai · October 28, 2001

well I was under the hood yesterday and took a look at the tank and it had 2 hoses instead of one the lower one goes directly to the lower radiator hose and the upper on goes to the top of the radiator

so it should fill just fine from the tank, sorry for the previous bad advice it aplies to older puke tanks

chevy4x4trucks · October 30, 2001

I had to drain mine to change the t-stat. On the side of the radiator there is a drain hose and I just dumped that into a bucket, and then refilled it from the clear tank in the passenger side of th engine compartment. If you plan on changing the fluid, make sure you use dex cool and cut it 50/50 w/ water and then buy a testor from the local auto parts store to make sure you have the correct mixture.

CMNTMXR81 · October 30, 2001

You do it the same way you'd do any system. The only difference is the fluid itself. Make sure you use Dex-Cool (or Tang as I call it) instead of regular Etholene Glycol (sp?), you know, the green stuff.

I also add to the radiator itself instead of the overflow tank, otherwise you'll never get an accurate and true reading as it doesn't flow back into the radiator as quickly as it spits it out.

After re-filling it, you may have to run it up to operating temps a few times in order to "burp" the system. Anotherword's re-pressurizing itself.

Only GM fwd vehicle's have a special "purge" valve that you need to pop when flushing it.

DT10 · October 31, 2001

Thanks for the replies. I read somewhere that you need to rev the engine to get it to pull the coolant in from the tank. I am a little concerned about this practice if the block is dry. I thought of adding directly to the radiator, but cannot see a cap. Thanks again.

DT10