So when I bought my Bronco, the radiator was really bad, so I went to AutoZone and got a new one. When I put the new radiator in, I found that I had no way of making my fan shroud fit. I took the fan shroud off and it disappeared somewhere, but it didn't seem to matter. This summer, I fixed the A/C and now when I drive in town or sit for more than a couple of minutes, my truck overheats. I had replaced the fan clutch, and it appears to be working. I put in a new thermostat but it still gets way too hot, and I mean pegging the gauge.
I bought a new heater core, which I'm going to put in today, just because what's in the truck is the original. Other than replacing the waterpump, which seems to be working fine, is the lack of the fan shroud enough to cause overheating? It does get a lot hotter even with the A/C off.
Does anyone know what year fan shroud I can use that will fit a replacement radiator? It is the Spectra Premium Radiator Part Number: B1451
Alternate Part Number: CU1451.
On another question, I was going to replace the waterpump, and bought one, but then I was reading horror stories about the old bolts breaking off and now I'm gun shy about trying it. This is my go to work truck and I am thinking maybe I should take it to a shop in case something goes wrong with that. The waterpump looks pretty old and rusty, but no detectable leaks or wobble.

Okay, searched the forum and found I'm not alone with the shroud thing. Apparently I need to find a shroud and punch some new holes into the radiator frame to make it work. Still have the same question though. Can the absence of the shroud cause the overheating?

 

Absolutely, the shroud directs the air flow across the entire radiator rather than just the area directly behind the fan.

 

Makes sense. I just picked up a shroud at the salvage yard for $30 from an 89 F150. Guess what, it lines up perfectly with the AutoZone radiator. I think I'm still going to replace the thermostat and heater core, just because I already have them and both are super easy to get to. Has anyone had any major difficulties with the waterpump removal, or am I being paranoid?

 

Something you could try is buying some Deep Creep seafoam thread breaker or some PB Blaster and just soak the bolts for a few days. Then take a 1/4" ratchet and whatever socket it is and just carefully wrench it off. In my experiences with other vehicles taking them off is easy, I break bolts putting them on. If you use a small ratchet or wrench then you are less likely to put a ton of force onto the bolt and break it.

 

Absolutely, if it's over heating sitting still or going slow, but not at speed then it's a fan issue and a shroud will do A LOT to help that.
Well not quite, while true for a good shroud that's not the most important aspect. Without a shroud the air will move in a circle out the end of the fan blade then back around in front of the fan moving the same air in a circle instead of being pulled through the radiator. The solution to this is two things, move the fan closer to the radiator and a shroud that surrounds the fan blade as close as is practical.

No you are not being paranoid at all, the long bolts that go through the aluminum cover on a 351W can be VERY problematic. Steel and aluminum corrode each other through electrolysis this can do 2 things. Corrode the bolts, I've seen then where the shank has gone from the 5/16 diameter down to under a 1/4. But most often it will seize the bolts to the aluminum cover.

My suggestion, don't replace the water pump until you have to. And until then every once in a while get some penetrating oil on the bolts and maybe try and turn them a bit. It won't hurt to unscrew the bolt a turn and tighten it again. Just turn them a little back and forth until they loosen up. When you can do that on all of them then replace your water pump. And don't let a shop do it, they are always in a rush and chances are they will break the bolts, then do some crappy fix.

 

Thanks for the advice. I got everything put back together and it seemed to run a little cooler just sitting in the carport. Now I have to go back in, in the morning, and redo my thermostat housing, it sprung a little leak once I got it full of antifreeze and under pressure. I don't think I've ever had one go right the first time.

 

You're not alone, we have all felt that pain. You think something is all fixed and ready to go till it leaks or doesn't work at all... I was changing the brake discs and bearings on my bronco and didn't know the proper way to pack bearing, or I was told how but didn't understand. I had one whole side done and back together and my neighbor comes over and asks if I've packed them and how I did it. I showed him and he said to pull it all back apart so I can pack them the right way.

One step forward, 2 steps back.

 

TESTIFY! If it went right the first time, I think it would be the first sign of the Apocalypse.

 

So, I guess the fan shroud is indeed important. Of course it may be a mix of that and fixing some other stuff. Here's what all I did. Replaced fan shroud, heater core and thermostat. Put in fresh antifreeze and my temperature is about a quarter inch below the hot mark, and that's with the A/C running full blast and sitting at stop lights and in town driving. So, thanks again for the help guys.

 

How much of what kind of antifreeze?

They say 50% for max protection but a higher percentage of water cools much better.

The yellow and pink antifreezes work better.

If you don't really need freeze protection the coolant additives like water wetter with just water can really REALLY help and provide the corrosion protection you need.

 

If I had to guess where I'm at right now, without putting a bulb to it, I think I'm about 60% water to 40% green antifreeze.

 

Anything water-based allows electrolysis of the water in the system. Remember that every metal object in the truck carries the negative charge from the electrical system so you aren't going to stop the electrolysis so long as there is a water-based fluid in the system. This leads to scale and corrosion. The best you can hope to achieve with a water-based coolant is to keep the electrolysis as slow as possible. Keeping the system full (as little air as possible except in the expansion reservoir) and maintaining a level of corrosion resistance to keep the process from advancing is your best defense against it.

 

Well, so much for that good feeling. Ran it today to work and within 5 minutes, it was at the edge of the high line. Coming home this afternoon, it got way up there again, but dropped just below the line when I turned the A/C off. Turned the A/C on again and it started getting above the high line. Turn it off, and it goes down. That being said, it still gets fairly close to the high line even with the A/C off. Any ideas?

 

Run the Heater if it's overheating and you need to keep going, it will work as a second small radiator (which it indeed is).

 

Yeah, but that gets me a bare fix and I'm in Kansas where it is over 90 degrees already, don't need the extra heat. I just ran it for a while with the heater going to see if there might be an air bubble in there. The water level bubbled up to the top of the filler then would drop down, bubble back up and down. That was pretty much the cycle, but I didn't get a lot of air bubbles from it.