Hi Every1
Today I drained all the coolant out from the drain plug under passengers side. And then I just refill the expansion tank with distilled water after I turned on the car. However, I now see the temp gauge is going up fast and then back down and repeat this again and again. I now know that this is due to air in coolant system. I now found that I need to bleed the system. I read the procedure below but I just don't know where the "radiator lower hose" is at? I need to disconnect it.



From the workshop manual (for the 4.0L V6):

1 . Position the vehicle on a lift.
2 . Set the heater controls to maximum.
3 . Disconnect the battery ground cable.
Specifications
4 . Remove the engine cover.
Engine Cover - 4.0L (12.30.50)
5 . Remove the coolant expansion tank cap.
6 . Remove the front LH splash shield.
7 . Remove the radiator access panel.
8 . Position a container to collect the fluid.
9 . Release the clip and disconnect the radiator lower hose, allow the coolant to drain.
10 . Remove the container.
11 .Connect and secure the radiator lower hose.
12 . Connect the battery ground cable.

Specifications
13 . Connect exhaust extraction hoses to the tail pipes.
14 . Loosen the coolant expansion tank bleed screw.
15 . Fill the cooling system to the upper level mark of the expansion tank.
16 . Start and run the engine.

��
Hold the engine speed at 2,500 RPM for 30 seconds.
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Return the engine to idle for 30 seconds.
�� Repeat the above procedure a further four times.
17 . Fill the cooling system, keeping coolant to the upper level mark of the expansion tank until a steady stream of
coolant is seen returning to the expansion tank. Tighten the bleed screw.
18 . Install the coolant expansion tank cap.
19 . Run the engine until the thermostat opens.
20 . Check the heater for correct operation.
21 . Switch the engine off and allow to cool.
22 . Install the engine cover.
23 . Clean any remaining coolant from the chassis and surrounding area.
24 . Install the radiator access panel.
�� Tighten the 4 bolts to 10 Nm (7 lb.ft).
25 . Install the front LH splash shield.
26 . NOTE :
When the cooling system is warm, the coolant will be approximately 30mm above the upper level mark on the
expansion tank with the cap fitted.

 

Well if you have already drained the system there is no need to pull the lower radiator hose. Typically found in the lower left or right corner of the radiator.

Just go through the fill and bleed procedure.

I just bought the vacuum bleeder and used it for the first time on my Excursion and my god that was the best $70 I have ever spent.

 

When you say bleed procedure, does it mean I need to pull the "radiator lower hose"? I only know where the drain plug is. A flat head screw driver will loosen it and it will drain there. In terms of the vac bleeder. I'm thinking to use my siphon pump to hand vac it from the drain plug. Maybe it will pull some air out from there?

Now its filled with distilled water but it still looks very pink. That means there were still a lot of old coolant inside the system. I heard that I need to drain and refill distilled water for 4 times to get most (maybe just 85%) of the old coolant out. And then I will fill the new coolant mix in. The new coolant I got is "ZEREX G05® Full Strength Concentrate Antifreeze / Coolant, 1 Gallon". It is Hybrid Organic Acid Technology (HOAT). But its gold/yellowish color not pink.

 

So you are still trying to flush the system then?

If you are trying to refill the system to run it and drain again start at step 14. Once that is complete than you can drain either by the drain plug you used previously or do the steps to get to the lower hose from the fender well. If you can get to the radiator drain that should do just fine and I would leave the hose alone.

The tool I’m talking about requires an air compressor and is attached to the expansion tank to pull all the air out than you flip a valve on the tool and pull coolant in from the container.

 

yes I do want to flush it coz I already got the new coolant and its different color.

 

What color is the new coolant????

 

"ZEREX G05® Full Strength Concentrate Antifreeze / Coolant, 1 Gallon". It is Hybrid Organic Acid Technology (HOAT). But its gold/yellowish color not pink.

 

Your original stuff may have actually been more of an orange originally. Either way, the two are comparable. Its the orange (pink) and green combo you never want to do!

Also tap water is generally okay for flushing less you have mineral rich water, then followed by some distilled. Dont over think it. In the end you need the expansionists tank and "T" bleeder onto the engine open to let air out.

 

Thank you for the advice. I forget to mention mine is 06 LR3 4.4L V8. I didn't drive it much longer when I saw the temp gauge going up. I stopped on the side of the road and turn the car off. I waited for about 20min and tried to re-start the car but it said low level of coolant. Luckily there was a goodyear shop like 1 block away. I ran it and they got bottles of water in the fridge. I got 2 bottles from them and pour it into the expansion tank. It started again and I just it for about 2 more miles before returning home so total about 5 miles. The temp gauge did the swing but I drove slowly. Hopefully I didn't damage any parts by that overheating. I heard that its very bad for the engine and the radiator and all the hoses too. Tomorrow, I will drain it again and hopefully I can find the lower radiator hose and bleed it from there. And then refill it with distilled water. I live in SF bay in California so just water may also be fine coz we don't snow here. There is really no need for anti-freeze / coolant.

 

Coolant is required to lubricate the water pump bearing and the additives prevent corrosion. You can run water for a while if you wish. Months even. But any longer, I would not. On very old cars just water was often okay because of design and simplicity of metals. Modern cars use coolant for more than just cooling.