2003 Silverado Coolant Flush

OchAyeZ71 · July 28, 2008

I have flushed several of my vehicles in the past using the basic method I describe here. The only difference is I have typically pulled the lower radiator hose. Since these trucks have a convenient drain plug, I decided to use it. I have also read some of the topics on this here and there are a variety of methods so I thought I would post mine. Hope it is useful.

1. Raised the back end of the truck (backed up on to some ramps). Thought this would help drain more out of it.

2. Drained the system from the radiator using the drain plug. Did not remove any hoses. Took about an hour or so. About 9qts came out.

3. With the drain still open I ran tap water filling up the resevoir until clear water flowed out.

4. Let all the tap water drain out.

5. Filled with 50/50 mix of DexCool and Distilled Water. Took about 1.5 gal initially.

6. Fired up motor and it took another 0.5 gal (filled while it was running). Left the resevoir cap loose until I could feel hot water flowing through the top radiator hose.

7. Drove it for about 2miles until the temp gage was reading normal, ran the heater also.

8. Parked it. And put about another quart or so in it. Then I took it for about a 10mile drive for an errand. No issues.

Mine has about 72k miles on it and just turned 5 yrs in June so I figured it was time for it. The coolant that came out of it was slightly discolored but still pretty clean.

unit731 · July 28, 2008

I would state that this is a good way to change fluid.

In the olden days every city had a radiator repair shop. Recore. Radiators were made out of steel and they rusted. And most old timers carried both an upper and lower hose in vehicle as spares.

Maybe I'm lucky. I bought my 1990 Chevrolet 1500 4.3 used 10 years ago. 88,000 miles on odometer. In the 10 years I owned truck the miles on odometer climbed to 140,000 miles. I never replaced the anti-freeze or hoses. I think the water pump was replaced but used the same anti-freeze.

On my new truck, I certainly will replace the anit-freeze at scheduled time. I guess, I'll have to look at manual and see when this is supposed to be done.

Sepiroth · July 28, 2008

I have flushed several of my vehicles in the past using the basic method I describe here. The only difference is I have typically pulled the lower radiator hose. Since these trucks have a convenient drain plug, I decided to use it. I have also read some of the topics on this here and there are a variety of methods so I thought I would post mine. Hope it is useful.

1. Raised the back end of the truck (backed up on to some ramps). Thought this would help drain more out of it.

2. Drained the system from the radiator using the drain plug. Did not remove any hoses. Took about an hour or so. About 9qts came out.

3. With the drain still open I ran tap water filling up the resevoir until clear water flowed out.

4. Let all the tap water drain out.

5. Filled with 50/50 mix of DexCool and Distilled Water. Took about 1.5 gal initially.

6. Fired up motor and it took another 0.5 gal (filled while it was running). Left the resevoir cap loose until I could feel hot water flowing through the top radiator hose.

7. Drove it for about 2miles until the temp gage was reading normal, ran the heater also.

8. Parked it. And put about another quart or so in it. Then I took it for about a 10mile drive for an errand. No issues.

Mine has about 72k miles on it and just turned 5 yrs in June so I figured it was time for it. The coolant that came out of it was slightly discolored but still pretty clean.

Good read. WHEN I change my coolant in the Suburban, I will not be going back to DEXCOOL. I will be using the yellow G-05, or the tried and true green coolant.