I was looking for graphic and/or written instructions for flushing my radiator on a 1998 Blazer LT 4x4 with the 4.3L Vortec V6, which I don't believe has ever been done. I am at 105K miles. Any help is appreciated.

Thanks,

Blazin 4x4

 

Why stop there?
Heres how I do it.
Buy new radiator hoses, upper and lower, new thermostat and gasket, water pump and gasket, water pump form-a-gasket, spray cna of gasket remover, gallon of anti-freeze, 2 gallons of distilled water, and a 6pack of your favorite beer.
Disconnect radiator hoses at the water pump and thermostate housing.
Take thermostate out.
Stuff garden hose in thermostat opening with a rag around it. Turn on water and let run for a few minutes.
Now stuff the garden hose in the water pump and let it run for a few minutes.
Now stuff it in each of the radiator hoses and let it run for a few minutes.
Replace water pump (form-a-gasket on both sides of cork gasket, install new thermostat, install new radiator hoses, add 1 gallon of anti-freeze, top off with distilled water. Drink beer for several hours while you wait for the form-a-gasket to cure. Once you sober up, fire up the engine and crank the heater. Let it run for 10 minutes and add distilled water as needed. Take it for a test drive. Once cool, verify anti-freeze mix meets your areas needs and add either anti-freeze or water to get proper mixture and top it off. Make sure to fill the overflow tank as needed too.

There way go, one cooling system ready to go for another 100,000 miles. Sure it'll cost you about $100, but that is cheaper then a tow bill or blown engine.

 

^^^^Definitely words of wisdom right there^^^^

I totally agree. If you are that high up in mileage, it is only a matter of time before the bearings in your water pump start to get tired. If you really wanted to get the block and rad clean before doing the swapping of parts, you can get a can of radiator flush and add it in a few days before (or whatever the can says) you do everything. As long as you flush everything out before putting new back in, you shouldn't have any problems. If it were me, I would premix the antifreeze and distilled water before dumping it in. In NY, I run a 50/50 mix in everything to make sure that the brutally cold days in the winter don't freeze up anything!

 

Hows that rad flush stuff work?
I have never tried it, but with the new anti-freeze I'd like to get everything out.

I have heard horror stories of how air got in the system due to a fualty rad cap and caused corrosion to build up in the radiator. I like the new anti-freeze. I like servicing the system once every 5 years. I am also due for a flush. Hoepfully before winter hits, and at the very latest next spring.

 

I flushed the rad on my '97 RAM, but that was only after I had to replace the heater core because the radiator had never been serviced in it's life (wife's truck before we got married...). The heater core was completely blocked off and wouldn't clear out even with reverse flushes and sitting full of vinegar over the course of 2 days... Vinegar is an excellent cleaning agent for cooling systems, but many of the radiator flushes work much better.

For just a flush of the cooling system (sticking with Green Antifreeze), a radiator flush such as Gunk 10-minute Radiator Flush. Now I have heard conflicting answers about rad flush chemicals in higher mileage cooling systems where the systems have degraded a bit already.

A safe way to go would be to just flush everything with clean, clear water. You would flush the radiator, engine and heater core separately. The heater core should be flushed both forwards and backwards (use 1 hose to flush it, then switch hoses) until all the water coming out is clean and clear. Just flush the engine and radiator until the water coming out is clean and clear as well.

Fill with 50% quality antifreeze (preston or equivalent) and 50% distilled water. The use of distilled water (if not evident) is to cut down on the minerals/contaminents that would be introduced into your cooling system. Distilled water is just H2O, nothing else, whereas your tap water has minerals and may other contaminents in it that could cut down on the life of your coolant.

For as expensive as a radiator cap is (<$15) and for that matter the thermostat too (<$10), both should be replaced each time you do a flush just as a preventative measure. A faulty radiator cap could undo any preventative maintenance you have performed on the cooling system. As caps age, the spring gets weaker and the seal hardens. This can allow fluid to escape at lower than stock pressures and could possibly result in a catastrophic overheating of the engine. The thermostat can have the same end result if it were to stick closed. Try to used quality products for these components. I have never had a Slant cap or stat fail on me or any of the vehicles that I have put them in (~30 different vehicles). Ofcourse, this was replacing them every 2 years when I would do radiator flushes on all of my vehicles and family vehicles.

I wouldn't trust the claims of the antifreeze manufacturers. I will be replacing my antifreeze (dexcool) in both my Bonneville and my Bravada in 2 winters. Both were just done this summer. I am cutting them short because of the horror stories I have heard about them. With a proper replacement schedule, everything will be fine!