Anti-freeze flush

[gmyeah]

I know you can test your antifreeze to see if it's still worthy of using, but what are people's thoughts on performing a replace/flush. I have a 2008 z71 sierra 4x4 ext cab......with 75K on it. I try to stay on top of maintenance....so curious what folks normally do.

[Carder09]

That seems a bit early to me. I think its good for over 100k but that's when I did a complete system flush and changed hoses.

[GuyGene]

I'd flush it, no matter if it says go to 100k miles. Coolant issues can be easily prevented by having clean coolant and a cleaned system, water pump, etc. Cheap preventive maintenance I think.

[txab]

Flush it now. Been in there at least 5 years. Consider replacing hoses at this time as well

[demech23]

I'd flush it, no matter if it says go to 100k miles. Coolant issues can be easily prevented by having clean coolant and a cleaned system, water pump, etc. Cheap preventive maintenance I think.

 

Get it flushed, I'd recommend using dex-cool extended life antifreeze with distilled water (pink/purple cap). I'd stay away from local Speedee & Jiffy-Lube all makes extended life and any cooling system cleaner and conditioner.

[chevydriver37]

Just did mine before I traded it in. I had 88K miles on the clock, but noticed that the coolant was starting to congeal on the bottom of the radiator cap, so I figured it was time.

 

I snapped my heater hose and used a Blast Vac gun to purge the system. Put the T in the heater hose, refilled with Dex, and distilled water, and was done in a little less than an hour.

 

A Blast Vac gun looks like a pistol, that you hook a garden hose and an air line to. It comes with multiple fittings to fit into various size hoses, etc. I ran it at about 20-30lbs of air pressure (no more, or you'll blow a water pump gasket!). It forces the water through the system, and when you're done, you can shut off the water and just run air through it to clear everything out.

[ujtruck]

last weekend I did mine and i do it every year

 

and be sure to purge all that air out of the cooling system

[Stex]

last weekend I did mine and i do it every year

 

and be sure to purge all that air out of the cooling system

 

With no cap to leave open, How? And do you just pop a hose to drain and flush?

[chevydriver37]

With no cap to leave open, How? And do you just pop a hose to drain and flush?

 

Get yourself a Lisle Coolant Funnel Kit #24680. Napa also makes has thei same thing with their name on it. It comes with a bunch of adapters to fit all the different radiator/coolant tank appliactions. Stick it on your coolant tank, and fill from there. Start your engine, fill the system, then fill the funnel up to within a few inches of the top. As your cooling system fills, you'll see the air purge itself and the bubbles will come up thru the funnel. I leave it for about a half hour, maybe less. Once the air is purged, you plug the funnel, remove everything, dump out the funnel and you're good to go. As far as flushing, you could do it a few different ways. Like I said above, I snap a heater hose and stick my flush gun in one end, and stick the other end of the heater hose into a bigger hose and let it drain into a big old container (that I can take to my buddie's dealer and dispose of). Not sure if it's the best way, but it's worked for me for a bunch of years so I stick with it. Hope this helps.

[GMCDriver1]

No one should think it is ok to run the 100,000 on their coolant, unless they put 100,000 miles on their truck every 3 years. Yes yes yes it says in the manual that it is good to 100,000 miles. And while it may LOOK good, by 60,000 miles it has lost much of it's protection and is starting to damage things. This goes for any extended life coolant, not just Dex Cool. DexCool got a bad rap in the earlier days and rightfully so, but mostly because people did NOT maintain their vehicles properly, and thought they could get to 100,000 miles without having to worry. ::buzzer sound:: They were wrong. So was GM. DexCool has been improved over the years but if you want to run 100,000 miles on your coolant or not change your spark plugs until 100,000 miles, do at your own risk.

[lryfer]

Dealer told me that all the fluid changes and coolant flush are not required until 100K. I have my sons Silverado with 51K all fluids changed coolant flushed with brake and steering. Was told no need dont waste my money.

 

Well i worked at a dealership and saw the issues through the years. So my vehicles get items changed constantly. As someone stated earlier cheap maintenance compared to the possible issues.

 

Will be doing my other 06 silverado with 47,900 miles at 50K. Got my sons truck all completed with flush coolant, PS Fluid, B fluid and all fuilds/filters changed for out the door after tax 800. No need to worry about it for another 50K.

 

Didnt think about the plugs. So what plugs to put in AC Delco or other? Gap is?

[txab]

AC Delco. .040 gap if it's on the '06 Silverado

[ujtruck]

With no cap to leave open, How? And do you just pop a hose to drain and flush?

 

yes Sir,

 

here is how I did it

turn heater all the way (no need to turn the blower/fans on)

 

remove the lower radiator hose, then remove thermostat and just install T-stat housing (don't supper tight those bolts)

refill with just tap water run the engine till its warm and flush (i do this about 3 times)

now install everything back and refill with 50/50 mix Dexcool

 

install reservoir tank cap <<-- don't tight all the way

start the engine

keep filling the reservoir while its warming (1 to 2 min) <-- don't run until over heat or water boil

shut off the engine

fill or make sure you have dexcool 1/2 inch above cold/full mark

 

 

now install reservoir cap really good

run the engine until pretty hot or rad fans kick in then stop the engine

wait till everything is cool - back to normal

add fluid if needed

[Gurrzt]

I would flush and replace the anti freeze every 40-50k, NO MATTER WHAT GM SAYS IN THE MANUAL.

[c4cruiser]

I would flush and replace the anti freeze every 40-50k, NO MATTER WHAT GM SAYS IN THE MANUAL.

Even if you pay to have the work done by a shop, a 40-50K interval for a cooling system service is a good idea. It's not that expensive compared to what you may have to pay to have done if you use the GM schedule in the owner's manual (My 2008 book shows 150K). But the manual also says that depending on the use a rig gets can change the frequency of service.