Best way to burp the cooling system

What is the best way to burp the cooling system ? Someone told me to raise the front of the truck on ramps to have gravity help. Any other pointers?

I also found these instructions but I am skeptical because they say run the engine while the funnel is still in the rad intake to get bubbles. Isn't that going to cause a sh*tstorm of coolant blowing out as soon as the thermostat opens? I though the rad cap has to be on tight every time the engine is on.

 

You can crank it up and run it without the cap on just fine. The spewing and hot steam is after the engine gets warm and pressure builds up with the cap on. Leaving the cap off, the engine will warm up until the thermostat opens then you will see the water running through the radiator driven by the water pump (after enough coolant is in there). No pressure or steam buildup that way. You can also keep watching the water level in the radiator and add when ever it drops down. The radiator fill cap is the highest point, so that is where any air will have to rise to eventually. Keep watching and filling until the radiator is full and no longer drops. There may be times when the radiator appears full then a big air bubble comes up and causes the neck to overflow. That might be the reason for the funnel, to minimize the spilled coolant.

What you want to do is get the major air pockets out and get the radiator full enough that the engine stays at normal temp (no overheating IOW). Then when you put the cap on, any further expansion and minor air burping should go out into the plastic overflow tank. That is the reason for the hot and cold marks in the tank. Assuming the engine is completely up to temp at this point, go ahead and add water to the overflow up to the "Hot" level. (If it is not there already)

Then keep a close check on the level in the overflow for the next few days. Of course it will drop to "Cold" after the engine cools, due to suction back into the radiator. Check the level again the next day after Hot again and if it's gone down from where you left it, that means a little more air burped out and coolant was sucked back in to radiator to replace it. (Or it's still leaking somewhere, but you should see it on the ground in that case.)

 

This leads to another question I have: if I do that exactly, is it possible to see that the thermostat is open when I see the coolant circulating when the cap is off ? also, is there any other way to tell whether the thermostat is in the on or off position while the truck is driving ? my guess is no because i just replaced the thermostat and didn't see any sensors going to it but i think it would be useful to have one to tell whether the thermostat is at fault by being stuck closed if the engine overheats. is there any other guidelines to at least guess if the thermostat is on or off (not just should be on or off because i know it should be on when the engine gets hot)?

 

Feel the top radiator hose. It should be "cool" at start and when thermostat opens, it should be hot to the touch.

 

The hose from the block to the radiator will get hot when the thermostat opens up if starting from cold. You should also be able to see the movement of the coolant when it opens. There should also be a vent in the intake that you can use to get the air out. Not sure right where on the 4.0 though.

 

If you don't have the funnel thingy, you can park your truck at an incline having the front end of the truck at the highest point. This makes the air flow to the radiator quicker.

 

I just took the water intake out (if that's the intake you're referring to) when I was replacing my water pump and didn't see any release valves. It did have about 7 hose fittings, 2 for the big rad hoses and 5 for little ones (cooling the oil filter and other components)

 

It would be a bolt or small valve on the intake manifold, around the throttle body maybe, with hoses running near it.

 

are you referring to the coolant intake manifold that's attached to the water pump ?

 

Another note: From your other thread, it sounds like you have it pretty close to full of water already. So if you are going to use jugs of pure antifreeze, you can try to measure the amount of water needed to drained out radiator spigot so it equals the antifreeze you plan to put back in. Then you are just about home free except for any topping off needed.

 

Lisle 24680 Spill-Free Funnel, Standard Adapters, 11 x 7 x 7"es

http://www.amazon.com/Lisle-24680-Spill-Free-Funnel/dp/B00A6AS6LY

 

is this something that is really necessary ? can it be done with a good ole plain funnel ? i hate how it comes with a dozen parts, kindof like a food processor

 

- it's not necessary, but it's the most mess-free approach I've ever used and I've used them all
- can you use a plain ole funnel - NO - why - because the kit SEALS the system. a plain ole funnel won't do that.
- you hate the multiple attachments - why? - there are multiple types of cars with various radiator necks/caps that are of different sizes.

 

+1 one on the spill free funnel . Also as stated above, Park your vehicle with the front slightly higher then the rest of vehicle .

 

Do it the same way you have already been using to add water throughout this saga. Sounds like it is full now anyway, except for some topping off to the overflow tank.