flush fill AND bypass tube?

Hi Folks

Need your opinion. I'm going to do a flush fill on my 2000 3.8. This is preventative maintenance before the fall/winter arrive. It has the original heater bypass tube in it and I'm wondering if I should count on replacing the tube as I know they're prone to problems. I don't have any leaks but reason that it'll just be my luck that once I've done the whole job I'll develop a leak at the tube. I also wonder if the metal pipe that exists the water pump and leads to the rubber flex hose which attaches to the rad bottom at the passenger side side also should be replaced. Rather do these jobs on my schedule than an emergency schedule.

Any thoughts?

I would say... check the condition (color, smell and feel) of the coolant, degas bottle (don't forget the cap too) and hoses first to determine if the cooling system is been compromised, contaminated or just plain rusted out beyond help!

But this is a Ford Windstar were talking about so I would say YES...! replace the darn bypass tube, which will also allow you to see the condition of the upper plenum and EGR ports and allow you to clean and manage them.

For the lower radiator hose metal extension... well if your Ford dealer is close enough go ahead and buy it and if not needed return it for a refund.

In my case when I replaced my water pump which had rusted out and contaminated the whole cooling system, I removed the lower extension hose thinking it was shot but it turned out to be in great shape! It was just covered in surface rust

This quote below explains what I did to it from another post: listed HERE (http://www.automotiveforums.com/vbulletin/showthread.php?t=1083590)

One thing that happened to me and might happen to others is that the lower radiator hose pipe or lower extension pipe had developed surface rust and the black coating cracked and peeled off.

Out of fear that the coating could loosen up and clog the cooling passages on the engine block, radiator or pump, I strpped the coating of the pipe as it striped off the pipe like old tape. But by doing so I did not get a good seal between this pipe and the Water Pump's inlet pipe when I put everything back together and developed a nasty leak!
The only thing that keeps a seal between this two pieces is an "O" ring... seriosly what a stupid design!!!!

So, I spent a few hours, removed the lower extension pipe to the lower radiator hose and sanded the surface rust and coating off the pipe to prep it for new coating.

Then I used Rust-Oleum High Heat Enamel Spray Paint to coat the pipe with new smooth surface to seal the bond.

I gave it enough time to dry, but not enough to harden so I could get a better bite, so after putting everything back together and adding the proper amount of coolant the joint started a very slow leak (like a drip every 20 seconds or so) which got me really annoyed, but after like 15 mins of running at operating temp the leak went away, then drove it for like 10 mins and no leaks... so, so far it worked!

If you don't want to take your chances get the part before you start the job.. I just refuse to pay ($42 online, so the local dealer might be much more) when the part just had some surface rust and other than the flaky coating, everything else was fine with it!

That was over 8 months ago, and the leak never came back!

Also don't forget the "Y" Pipe at the top of the Water Pump which is also a very weak spot on this cooling system design.