Water pump failure destroys radiator

[VAL]

Answers to some of your questions/comments:
The reason the fan is spaced forward is that I've installed the much longer radiator that was only used in the 2WD 454 models. The fan shroud that fits that radiator is not very deep, because the 454 engine sticks forward toward the radiator more. It's a standard fan spacer that's available from NAPA or other sources (not that that means anything, of course). All bolts and nuts are still tight.....so there was no failure there. It's simply a sheered off water pump shaft.

As for the condition of the pump. It is very likely to be an original GM pump, and it could be the original pump, now with 298k on it. I purchased the truck at 224k, in 2004, and I can't remember if the pump looked brand new at that time, or not. I kinda doubt a pump could live 300k, so it may not be original, but the original owners (who I got the truck from) always had it serviced at the local GMC dealer, so even if it's not the original pump, it's an OE pump that predates all the crap made in China (like the Bosch pump photographed above). And that's why I've never touched it......because I knew it was excellent OE GM quality, and I knew if I put something new on it, no matter who I purchased from, I'd be getting China crap that would fail in 18 months or sooner.

My buddy down the street helped me trailer it home this morning.

I was able to straighten out the fan blades with a little finesse from a BFH and an anvil. Hammer-to-fit-paint-to-match.

Photos of the carnage for your viewing pleasure:

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Damn, looks like something out of a horror flick!

 

[skysurfer]

I wouldn't trust that fan to spin true after being mangled like that. You gotta ask yourself, "Do I want to buy a new fan now or replace the radiator yet again sometime soon?"

 

[jetman]

I wouldn't trust that fan to spin true after being mangled like that. You gotta ask yourself, "Do I want to buy a new fan now or replace the radiator yet again sometime soon?"

x2 Those fans were designed/built by the OEM to operate at a wide range of speeds all the while avoiding destructive harmonic vibration. Even though it may appear "straight" I would avoid placing it back in service.
Good used OEM fan assemblies from the pick-a-part lot are a dime a dozen..

 

[CorvairGeek]

x3
The fans themselves can come apart with catastrophic results.

 

[austinado16]

Points well taken guys, thanks. I'm going to lose the spacer and do something with either aluminum flashing, or maybe cut the deeper part of the original small block shroud and adapt it to the shallow shroud.....in order to bring the shroud rearward to the fan.

The wrecking yard situation around here is really lame, but I'll make an attempt to get another fan. If the yard here don't pan out, I'll hit the forum here and see if someone can grab a counter-clockwise rotating fan and send it to me.

 

[VAL]

I put a fiberglass fan off a 2000 blazer(reverse flow), on my serpentine conversion, it pulls alot more air than the metal fan, and weighs less.

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[austinado16]

Thanks for the photo of that fan installed. Does it fit over your engine's original fan clutch, or did you use the 2000 Blazer's fan clutch?

Actually, I wouldn't mind using this opportunity to install a big electric fan, which would probably give me back 1-2mpg, and make a noticeable noise difference. But I do so much mountain towing, in the heat, at low speeds, that I'm kinda concerned the electric fan set up just wouldn't move enough air.

 

[RetroC10Sport]

Thanks for the photo of that fan installed. Does it fit over your engine's original fan clutch, or did you use the 2000 Blazer's fan clutch?

Actually, I wouldn't mind using this opportunity to install a big electric fan, which would probably give me back 1-2mpg, and make a noticeable noise difference. But I do so much mountain towing, in the heat, at low speeds, that I'm kinda concerned the electric fan set up just wouldn't move enough air.

A dual fan setup would move more than enough air needed.

I have a single fan from a T-Bird on my 1989 Sierra, on a 105 degree day with the A/C running and sitting in traffic, the temp never went above 200 with a 180 degree 'stat.

 

[VAL]

Thanks for the photo of that fan installed. Does it fit over your engine's original fan clutch, or did you use the 2000 Blazer's fan clutch?

Actually, I wouldn't mind using this opportunity to install a big electric fan, which would probably give me back 1-2mpg, and make a noticeable noise difference. But I do so much mountain towing, in the heat, at low speeds, that I'm kinda concerned the electric fan set up just wouldn't move enough air.

I removed the blazer clutch, and bolted on my own clutch to the fan.

 

[yevgenievich]

I still have not found a fully decisive info for electric fan operation on a scenario going up on a grade at 35-40 mph screaming at 4k rpms fully loaded and towing an 8k load with ac on and 45*C weather.
I have the new fiberglass/plastic fan using original style hd clutch on my suburban. I will probably move eventually to electric, but maybe at a much later time.

 

[MikeB]

Here's how I've had the fan mounted, for about 2 or 3 years.......with that 1-1/4" fan spacer. Could that have caused the water pump shaft to sheer off at the front of the pump, because the weight of the fan & clutch is moved so much further out from the bearing in the end of the pump?

Hard to say, but I know pumps for use with conventional pulley systems are available in 5/8" and 3/4" shaft size.

And you may want to look for a fan with aluminum blades. Heck, I've had success with wide-blade 17" Derale flex fans, but admittedly those were not tow vehicles.

 

[austinado16]

I still have not found a fully decisive info for electric fan operation on a scenario going up on a grade at 35-40 mph screaming at 4k rpms fully loaded and towing an 8k load with ac on and 45*C weather.
I have the new fiberglass/plastic fan using original style hd clutch on my suburban. I will probably move eventually to electric, but maybe at a much later time.

My scenario is 25-35mph on a 7%+ grade, 2 lane, with plenty of curves, typically in the 90-100*F outside air temp range, with a 2,500lb camper on the hitch, and 3 people, plus some gear on board. The grade is about 30mi long, in both directions, with a peak at 7,000'.

Meanwhile; I got the radiator removed today, and will take it, and the spare 6.2 radiator to the radiator shop tomorrow. Big surprise when I laid the 2 radiators (my existing 454 version and the spare 6.2 version) in the bed of my pickup. Suddenly noticed that the 454 version core didn't use the full width of the tanks......in other words, the tanks are wide enough to accommodate a 5 row, but only a 4 row core was in place. The 6.2 used the full width of the tanks! So it is even thicker, than the 454 version that I've destroyed. And yet I have another 6.2 spare, that has a core that's the same thickness as my 454 version.

So this little fiasco may wind up leading to yet another upgrade in cooling system capasity!

The water pump and p/s pulley arrived today from Rockauto. Ordered them yesterday! $41 for the high flow GMB pump. The local parts place wanted $100 plus tax for it.

 

[austinado16]

All the parts have arrived, and I picked the radiator up from the radiator shop today.

Does anyone have a counter-clockwise rotating fan they'd like to sell. It would have to be from a TBI small block engine.

 

[yevgenievich]

Unfortantely i have already discarded two of them due to lack of interest

 

[austinado16]

Took a chance at the local yard today. They had a complete '89 R2500 Suburban. Sadly it was missing the big radiator. But it did have the reverse rotation 454 fan with clutch, a perfect shroud and top closing panel, and a baffle that I didn't know existed, which mounts on the back side of the core support, behind the driver's headlights, and channels air into the core. In a nearby 6.2 pickup, was another top closing panel, and a big 6.2 "VE" (4 rows of 3/8" tubes on 3/8" centers) radiator.

Talked to the radiator shop owner about how deep the fan blades actually should be in a shroud, and did some online reading as well. The consensus seems to be that just the leading edge of the blades need to be inside the shroud. Some say by about 1/2" and others say 1/3 of the blade.....and that the rest of the fan needs to be outside the shroud. This allows the leading edge to pull air from inside the shroud only, and then that air exhausts out the top of the remainder of the blade, which is why that portion of the blade needs to be outside the shroud. This applies to mechanical fans, not electric.