So, I decided to try to change my own radiator fluid in my 2003 4WD 4.6L V8 F150.

What I did (details if you want them):
I drained the coolant from the radiator. The plug on the engine is totally frozen, so I couldn't get it off with the tools I have. I decided to fill the radiator with normal water from the hose and run the truck until it got to normal operating temerature (with the heater on full blast). I figured this would help flush out the fluid in the engine. I drained that, and am doing it again. Currently, I am waiting for the truck to cool down to drain it and put in the anti-freeze.

What I noticed:
When I looked under the truck, I noticed a drip under where the passenger sits (around that area). When I turned off the heater, the drip stopped. When I turn the heater back on, the drip started up again.

It appears there is some kind of drip tube close to where this leak is occuring, but the leak is NOT coming from that tube...it is a little closer to the center of the truck.

I may have over filled the radiator a little bit and think it might have to do with that.

Any ideas? Is this normal? After all, all I did was just drain and fill my radiator a couple times...that's it!

BTW, it is about 83 degrees and sunny today, if that makes a difference.

Thanks,
Tom

 

You have to get that plug off the engine to fill it proper/totally otherwise you'll have a bubble in the cooling jacket. You should also measure how much fluid you are putting into the system to know if you indeed have it filled. Compare to the capacities chart in your owners manual to see if you in fact have it filled correctly.

Not good using a hose! I have a soft water system in my house that I also use for my cooling system, but if I didn't have it available I'd buy and use distilled water. Hard water is not a good thing for a cooling system.

 

Almost forgot! As for the leak, did you have the defroster on? If so, the a/c compressor works in tandem with the defrost and that leak could have been the sweat from the a/c system.

 

Ah, yes! I did have the defroster on!

As for the distilled water, I was going to fill it with the distilled water, but just flush it with the hose water.

Any tips for getting that plug off?

 

It's on the top of the engine right? Can you get any liquid wrench or pb blaster on it? Let it sit a bit after soaking with above and apply a little extra elbow grease and she should give it up.

 

That is the condensor drain for the A/C.

 

Honestly you do not need to screw with any block plugs and hard water will not destroy the engine. Yes distilled is better but not a necessity. When I do mine I flush it with a hose and it gets filled with hard water or lately I get the 50/50 mix. I also have never had a problem with air bubbles. I did get one the first time I pulled my radiator, the temp gauge spiked for a few seconds, but it burped right out by the time I got back home. Most people fill and then let the engine run with the radiator cap off. If you buy the premix 50/50 it won't matter how much came out. If you do not and live where it gets cold (under 0F) I fill with a gallon of coolant then a gallon of water and repeat until full. That way there is always a bit more coolant plus if you think about what water is left in the block it comes out fine.

I have done 3 or 4 flushes now and have over 200K miles on the system with no problems. I also like to run straight water with a small bottle of cleaner for a few days when I flush it to really clean stuff out.

Also when you fill the system you can squeeze that upper radiator hose to work the coolant up into it and get the air out.

 

Great advice!

I ended up NOT messing with the block drain plug. I did pretty much what you said but let it drain while filling it to try to circulate some of the stuff draining. It worked out well. I have replaced 2 gallons of coolant and have one more to put in, but i will have to drain about 1 gallon to get this last gallon.

Thanks for the help, it makes me feel better about how i did my flush.
Tom

 

All I'll say more on the subject is they install those plugs for a reason, and I gave the reason. To each their own on the hardwater issue, but I'll stick with my ideas on it.

Can't say for sure if using soft water is the cause of the longevity of my cooling system, but I haven't had as much as anything happen to my system, including water pump failure. I have the original water pump on my truck and the miles are listed below.