So, I'm around 100,000 miles on my '03 4.2L V6 and thinking now might be a good time to replace the water pump.

Will start with a coolant flush. Then replace the components.

RockAuto Shopping list includes :
--Gates water pump
--Upper/lower Gates hoses
--Motorcraft thermostat

Anything else I should consider ?

 

Is the water pump having problems?

 

Not right now. Hoping to keep it that way.

It's due for a radiator flush so may as well catch it all.

 

I have 200k on mine, still the original water pump.

 

Good to know.

I am a bit paranoid since I had a pump disintegrate while on the highway in another vehicle. Things got a little exciting. Stuff started happening very quickly..

 

I'm actually just finishing up doing mine ('97 4.2L V6) The water pump on this engine is a bit tricky to get to/change. 150k for me, so now may be a good time to do it, but you may be good for another few years. (Next time you need a flush perhaps)
I just went with the Cheaper GMB pump. We'll see how it goes, but for $8 I didn't think there would be much difference.

Just a flush and changing hoses is probably 1-2 hours, the pump's gonna add at least 1-2 more, depending how well you know what you're doing. (Took me like 6, I'm also only 18 and working in my driveway between work and finishing my senior year.)
Can't say much more for parts. Maybe a spare O-ring (size #13). The one that came with my new pump broke when trying to put it back in. $0.50 is better than having to go back to the store.

If you do decide you want to. You may as well do the flush after, since you're gonna have to drain the radiator to change the pump. The drain hole/location sucks so you'd probably rather only wait for it to drain once.

Make sure to find/have the right size wrench to take off the fan and hold the clutch still. (From the front end, Fan turns counter-clockwise, and the clutch clockwise)
Mine had 8,10,13,15,and 16mm bolts to get to it. (I'd have to double check if it was the original pump or not)

There's also a bracket between the water pump and A/C compressor bracket:
One of the bolt's wont come out without taking off the A/C compressor clutch. (I just loosened and swung it out of the way.
It has a "nice" air hole on top that if your engine bay isn't clean can have dirt in it then you have a heck of a time trying to clean dirt out of an 8-inch deep hole.
I have pictures here: https://www.f150online.com/forums/19...ge-issues.html

There's a "Y" pipe coming from the top of the pump. take off the 8mm bolt and it should pop out with a bit of twisting. You can slide it down and out with some movement, probably best to add fresh silicon to it.

Thermostat isn't in vertically, the hose coming from the top of the radiator goes into a bent up pipe. You have to take that off to get to the thermostat.

Oh and in front of it all is an insanely annoying set of wires. (Thanks Ford) So if you want to put in the effort to unhook/move those out of the way you can. I only unhooked the middle one since that was the only one easy to get to.

Hope this helps!

 

Thanks Plerp Isaiah. Great write up with lots of good tips.

It'll be a while before I actually get to this job so I will be gathering all the info I can before I start.