I’m very fond of the Marshal, my 1989 Ford F-150, a generous gift from David, though it hasn’t really proven to be the trouble-free workhorse it really should be, and I think I have myself and the cruel realities of time and physics to blame for that. Sure, the inline-6 300 cubic inch/4.9-liter engine is the robust beast legends claim it is, but it’s all the crucial bits bolted to it I haven’t exactly had the best luck with.
On the way home from first getting the truck, it was the alternator that failed. I replaced that, then later it was the starter, which I also replaced, then some teeth on the flywheel broke and I ended up having to start it with a wrench for far too long (I need to return that wrench to David, btw) but then I finally replaced the flywheel and clutch and I thought all was finally great!
And then it overheated, suddenly and dramatically, as I returned from a day of taking the kid canoeing. Ugh. What did my truck to so horribly in a past life as a washing machine or industrial mixer to have to pay so dearly in this life? Anyway, I was dealing with this:
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This time, though, I thought I’d actually try and solve the problem instead of letting it just sit forlornly for months and months; I think this time I got to it in just, what, a month? Something like that. It’s progress!
My friend and colossal helper of misguided projects, Andy, once again offered his well-appointed shop and well-organized tools and considerable expertise to lend me a hand, so I babied the truck over to his shop and showed up with it geysering steam like what I imagine a red-hot meteorite landing in a Vegas casino fountain would be like. But, the truck made it, barely, and that’s what mattered.
It looked like the water pump was the culprit, as that seemed to be where the coolant was escaping, and there was also a loss of power steering, which seemed to be the result of drag from the bad water pump on the serpentine belt. You can see the offending water pump in the middle there, revealed by the removal of the fan and belt and hoses: 
I got a new water pump from Advance Auto, and it seemed to be a match for the old part. It fit in the old pump’s place just fine, once the hoses and bolts were laboriously worked off, but pretty soon we realized that something was, well, different.
The new part had some different dimensions for no good reason I could figure out. The casting was thinner around the bolt holes, which meant that the original bolts couldn’t hold it firmly to the block, because they were now too long, thanks to the thinner casting. We compensated for this with some nuts:
The bigger ass-pain was that the threaded bit that held the fan clutch in place had become, again for no good reason I can determine, smaller. By like, 5mm or so. Why? Why, why, why? What was gained here? Were both of these changes just to save a bit of metal? Was it just cruelty? What possible engineering advantage could have come about from this change?
In the end I had to buy a new fan clutch, too, because some engineer somewhere had to listen to some drip above them who decided that all the dimensions on this water pump needed to be changed just enough to make life harder and more expensive for some poor bastards who dared to try and replace the damn thing.
Finally, it did get replaced, and we also pulled the radiator and flushed it out, causing it to disgorge several clumps of an unpleasant brown muck that resembled, in size, shape, color, consistency and level of appetizing nothing so much as healthy human turds.
Some of the coolant looked like maybe there was oil in it, which is, of course, not good. I showed David the engine oil, though, and he seemed to think the engine was basically okay, so I’m just going to go with that until I get proven otherwise, likely on the side of the road in the rain somewhere.
The point is the truck runs again without creating more clouds than the break room of a vape store, and once again I’ve been reminded that wrenching on cars is always an ass-pain, somehow, somewhere.
Why did they change the sized of that damn water pump? Who stood to gain? Oh well.
“What did my truck to so horribly in a past life as a washing machine or industrial mixer to have to pay so dearly in this life?”
Maybe it was originally The Mangler?
Some of you might know about Stephen King’s 1972 short story titled “The Mangler” about an industrial laundry press that developed a taste for blood: https://en.wikipedia.org/wiki/The_Mangler
And they managed to make not one, not two, but *three* movies based on that despite it being only a short story (the first one was directed by Tobe Hooper and starred Robert Englund, don’t know why it’s not better known, ha.)
ETA: I work part time doing repairs for a small dry cleaning shop; as I was finishing typing this comment I got a text about one of the presses not working properly. Spooky. Off to work I go. Hopefully it’s not something ominous…
Some commenters asked whether you got the wrong part or were given the wrong part which reminded me of something I’ve read about/been told about re: Ford parts in the mid-to-late 1990s.
Sometimes people would ask at the auto parts store for something for their late model truck and get the wrong part because they would say it was for a 1990 Ford F150 but the parts counter clerk would hear it as a 1994 F150 and vice versa, that is, they would say it was for a 1994 F150 but the clerk would hear it as a 1990 Ford F150. Since there was a switch over from the eighth generation (the Marshal) to the ninth generation in ’91-’92 so many things were indeed different for a ’90 F150 and a ’94 F150…
I had a ’75 F100 Ranger with the 300 inline six. This was before I really knew what the hell I was doing, and the coolant mixture in it was too high in water content when I drove it in a North Dakota winter. One evening, I was driving home with my wife-to-be, and the engine overheated because the coolant had frozen up in the cooling system in the -30°F weather. We had the truck towed home where I let it thaw and put in the correct coolant volume in it. Started as if nothing happened at all. I still replaced the head gasket prophylactically in the spring, but yeah, it was fine.
This is surely a sign of a limited vocabulary, but prophylactically put some very weird images into my mind.
I’ve replaced many water pumps over the years, it’s a common failure point, many had crappy impellers, or bearings. It is critical to thoroughly clean the mating surface on the block to get a good seal. The differences between old and new in this case are significant enough to send me right back to the parts counter with both in hand.
Jason, don’t you know that the compensating nuts go on the trailer hitch, not the water pump?
Merch idea!
The ones on the trailer hitch are the overcompensating nuts.
Working on modern cars is like working on plumbing – it ALWAYS takes three trips to the store and five times the amount of time I expect.
And by “modern,” I mean anything built since 1972. Get off my lawn.
Glad to see the truck back on the road. Keep at it. Eventually you’ll replace all the fragile giblets and it’ll be good for another geological age.
looks to me as if either you asked for the wrong pump or you were given the wrong pump
Bad parts are the big challenge to maintaining anything.
Nippon Denso cautions they are having a hard time with counterfeit parts.
I see rock auto claims to offer OEM Denso starters for my application at half what I just paid. How?
The difference is I bought through the direct Denso supply chain.
Judging by the price of denso spare parts I bought, I think I paid wholesale. It’s a new made in Japan Denso part.
What are they selling for close to $100?
I couldn’t get a quality water pump for a big Ford engine once and found one at advance for temporary use.
Lifetime warranty very cheap..
It was rough cast, covered in black grease, but the machine surfaces were precise and the bearings good. I learned to tell the finish of cheap parts a long time ago and the surfaces that mattered looked good.
When I fitted it, everything was a precise fit.
It came in a plain cardboard box and was marked as Russian.
It’s still on that engine.
I’d buy more from that supplier if I could get them.
I spend far more time researching quality parts than I do installing them, stock or modified.
On serpentine belts, they over tension water pumps and make them fail.
Give me a separate V belt.
It’s unfortunate that spending more on a known brand, or more still for OEM branded, doesn’t guarantee that’s what you’ll get. Counterfeiting is a scourge.
Direct supply chain sounds like money well spent. If you pay for Denso, or Bosch or whatever and get a knockoff you might as well have bought the CARFZZT part off Temu…
Torch- was it a Carquest Premium water pump or a Driveworks? Which store was it? Is there any way to PM me relevant information?
carquest premium
part number T5066?
Those compensating nuts are not the truck nuts I was expecting.
They just need a little nut mustard.
Looking at RockAuto, the Gates pump for the 1988 F-150 for the 300ci I-6 has the same hose attachment features as the pump you removed, but this style pump isn’t an option for the 1989 models, though the bolt holes still seem to have thinner metal and the clutch mount is still a smaller diameter: https://www.rockauto.com/en/moreinfo.php?pk=948787&cc=1121779&pt=2208&jsn=871
I had to go back to 1985 to start seeing some features like yours, I wonder if your whole assembly was replaced with a u-pull part at some point? But then again, the squiggly tube didn’t appear until 1986. Mystery indeed
That’s what I was thinking: that the engine was swapped for a similar motor of a different year, or from a van or HD model or something.
So I’m confused. (What’s new?)
Based on what I saw in the video it seems you have a burst cooling hose – Which makes sense given the truck’s age.
How did you determine you actually needed a new water pump?
I actually saw it leaking coolant, and the power steering issues from drag on the belt
I have The Marshal’s big brother, a 92 F-250 with the 300-6. It overheated 3 times because it kept shredding serpentine belts. Turns out the balancer rubber cut loose and the outer pulley kept shifting in and out periodically until it carved a groove in the timing cover and started leaking oil. Then I finally figured out what was going on. The whole time (this went on for a year!) it kept spinning the accessories fine.
Anywho, long story long, that engine can take the overheating. I always managed to limp it home, though 1 time I kept having to pull over at lakes and streams and douse the engine with water to cool it down.
Aftermarket parts can suck. The water pump I replaced fit fine and I was able to reuse the fan clutch, but the aftermarket clutch master cylinder I installed is tilted at a 30 degree angle, reservoir and all. I double checked it was the right part and it has worked ok, but really?
I have vauge memories of Ford doing this kind of annoying minor changes between model years for no apparent reason all during the 80s and 90s. Mostly on ancillary parts such as your fan clutch. The basic engines and like 95% of the parts would remain the same for decades but some small shit would change all the time for no apprant reason I ever saw. You had to know the exact year and in some cases even 1/2 year to get the right part.
Something like this is probably the culprit. That and every parts store’s database indicates that they are all the same.
Don’t we have a parts counter database guru here? Love it if he’d comment on this.
They seemed to have had a heavy duty option for the water pump.
Ford did that with the 2009 Escape. Halfway through the model year they switched it from a cartridge oil filter to a spin on.
I encounter that with engine components on my ’98 Ranger 4.0 OHV all the time. One example, the gasket between the upper and lower intake manifolds has different thicknesses, but is otherwise identical, depending on model year. Never figured out which year I ended up with though. Eventually got the correct thickness gasket.
“It is highly recommended that the fan clutch be replaced with the water pump
Used mostly on models equipped with a fan clutch” Directly from Advance’s website
yes but what about trying to be a cheap bastard?
And that doesn’t explicitly say you HAVE to, just that is recommended.
Just means an extra trip .. sometimes
It sounds like maybe the parts counter guy have you the wrong part? The dimension differences just sounds like the typical Chinese recreation parts experience but the actual clutch being a different size makes me think there was some dumbass rolling model change that nobody at Ford told anyone about except for service tech and/or some extremely specific combination of original options led to a different part being specced at the factory. I dealt with the latter a lot with my Corvette.
So the radiator shit itself? Would one say it was… lavishly?