Flushing, Draining and Filling Cooling System 150K or 5 years

[70Nova SS]

Flushing

Important: Do not use a chemical flush.

Store used coolant in the proper manner, such as in a used engine coolant holding tank. Do not pour used coolant down a drain. Ethylene glycol antifreeze is a very toxic chemical. Do not dispose of coolant into the sewer system or ground water. This is illegal and ecologically unsound.

Various methods and equipment can be used to flush the cooling system. If special equipment is used, such as a back flusher, follow the manufacturer's instruction. Always remove the thermostat before flushing the cooling system.
When the cooling system becomes contaminated, the cooling system should be flushed thoroughly to remove the contaminants before the engine is seriously damaged.


Drain the cooling system.
Remove the coolant recovery reservoir.
Clean and flush the coolant recovery reservoir with clean, drinkable water.
Install the coolant recovery reservoir.
Remove the thermostat.
Follow the drain and fill procedure using only clean, drinkable water.
Run the engine for 20 minutes.
Stop the engine.
Drain the cooling system.
Repeat the procedure if necessary, until the fluid is nearly colorless.
Install the thermostat.
Fill the cooling system.

Draining and Filling Cooling System (LL8)


Tools Required
J 38185 Hose Clamp Pliers
J 26568 Coolant and Battery Fluid Tester
Draining Procedure

Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.

Important: Draining the cooling system with the pressure cap installed will syphon the coolant from the overflow tank.



Park the vehicle on a level surface.
Allow the engine to cool.
Remove the radiator cap.
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
Place a drain pan under the lower radiator hose connection at the bottom of the radiator.
Using J 38185 slide the hose clamp back on the hose.
Slowly remove the lower radiator hose and drain the coolant into the drain pan.
Inspect the engine coolant for the following conditions:
Discolored appearance-Follow the flush procedure.
Normal in appearance-Follow the filling procedure.
If a complete block drain is required, remove the plug located on the LH side of the block.
Coolant Filling Procedure

Notice: The procedure below must be followed. Improper coolant level could result in a low or high coolant level condition, causing engine damage.



If a complete block drain was required, install the plug.
Install the lower radiator hose.
Using J 38185 slide the clamp into the original position.
Lower the vehicle. Important: Slowly add a mixture of 50/50 DEX-COOL antifreeze and deionized (Distilled works too)water to the cooling system through the top of the radiator until full. Refer to Capacities - Approximate Fluid.
Remove coolant recovery reservoir cap.
Fill the coolant recovery reservoir with the remaining coolant.
Install coolant recovery reservoir cap.
Install the radiator cap.
Start the engine.
Run the engine at 2,000-2,500 RPM until the engine reaches normal operating temperature.
Allow the engine to idle for 3 minutes.
Shut the engine OFF.
Allow the engine to cool.
Top off the coolant recovery reservoir as necessary.
Rinse away any excess coolant from the engine and the engine compartment.
Inspect the cooling system for leaks.
Inspect the concentration of the engine coolant using J 26568.

Source: Alldata.com

Good info

 

[Mark20]

Of course I did it a couple of weeks ago and now I read the instructions. It actually isn't that bad of a job. The worst is waiting for it to cool before you can do a drain. The origianl Dex-Cool came out looking very very clean. Not a bit of sludge in the hoses or on the thermostat. I used distilled water since we have very hard water here and I figured why risk sludging things up.

 

[70Nova SS]

Of course I did it a couple of weeks ago and now I read the instructions. It actually isn't that bad of a job. The worst is waiting for it to cool before you can do a drain. The origianl Dex-Cool came out looking very very clean. Not a bit of sludge in the hoses or on the thermostat. I used distilled water since we have very hard water here and I figured why risk sludging things up.

Ya I'm getting ready to do mine too in the next day or so and figured I'd share. Trivial stuff but it's always worth a second look to make sure nothings missed. Hoping I can get away with just a drain and fill, I'll find out whenever I pull that lower hose I guess...

 

[Vicompc]

Good DIY instruction, one question. How do you back flush the radiator and remove the T-stat? Isn't the T-stat integrated into the fitting?

 

[djthumper]

Of course I did it a couple of weeks ago and now I read the instructions. It actually isn't that bad of a job. The worst is waiting for it to cool before you can do a drain. The origianl Dex-Cool came out looking very very clean. Not a bit of sludge in the hoses or on the thermostat. I used distilled water since we have very hard water here and I figured why risk sludging things up.

I wish our water was like yours. Ours is rated some of the hardest water in the country.

Good DIY instruction, one question. How do you back flush the radiator and remove the T-stat? Isn't the T-stat integrated into the fitting?

This is just a generic write-up that was found. You also have to consider that our trucks run Dex-Cool not the regular coolant.

 

[70Nova SS]

Good DIY instruction, one question. How do you back flush the radiator and remove the T-stat? Isn't the T-stat integrated into the fitting?

Good point, I'm guessing the dealership probably cut out a T-stat just for flushes or they have an over priced adapter that does the same thing.
View attachment 16994.jpg]

 

[Mark20]

Good DIY instruction, one question. How do you back flush the radiator and remove the T-stat? Isn't the T-stat integrated into the fitting?

You remove and replace the the whole fitting with the thermostat at one end. Really its just a long housing on the T-stat.

When I was picking up distilled water and Dex-Cool I also bought a stubby 15mm flex head ratchet wrench. Expensive but it made the lower alternator bolt pretty quick. I did need to use a regular wrench to get some leverage to loosen and tighten.

First took off the serpentine belt and lift bracket then tackled the lower alternator bolt followed by the top ones. Then drained radiator via the lower hose and leaving the radiator cap on but taking the recovery tank cap off does end up sucking it dry. Top bolt of thermostat is easy but easiest way to get to its bottom bolt was through left wheel, didn't have to take the wheel off, its a straight shot just over the 10 o'clock position on the wheel though I did need a lot of extensions.

 

[Sparky]

Thanks for the reminder that I need to do this. Now that it has gotten cold outside... Should have done it when it was still warm

 

[70Nova SS]

Thanks for the reminder that I need to do this. Now that it has gotten cold outside... Should have done it when it was still warm

Story of my life, I don't fix the A/C till we have triple digits and don't even think about the coolant till it's cold enough to freeze.