Hi there,
'82 F100 351c with AC

I have a few symptoms showing up during hotter weather. On a normal cool day my temp stays fairly constant at the lower end of the "N O R M A L" temp gauge. No issue there.

But on a hotter day...we commonly get 90+...the truck is struggling once we leave the highway. Traffic lights, etc around town quickly cause the temp to go past Half on the guage!

I believe my thermal fan clutch is not working as I have never heard it "roar up" on a hot day... so I will be replacing that along with a professional clean and flush (including new themostat). But my real question is, will a properly maintained system along with a working clutch fan be sufficient to keep my rig cool, even during slow speed around town?

Have toyed with the idea of electric fans but would rather keep standard setup if possible. I want to be able to drive it regardless of weather and not stress if I have to go into town.
Thanks.

 

Yes, the factory stuff is just fine for all extremes, provided it's in good working order.

 

As Chris stated, your system should maintain adequate cooling if it is in good working order...

If your AC is factory instead of add-on.. you will have the bigger radiator,etc for it..

If it were me, I would make sure that it is REALLY a problem BEFORE spending a lot of money....

By that, I mean I would put a MANUAL temp gauge on it to be sure that the factory gauge is correct..(they have been known to be unreliable).

You could hook one up temporary or permanent and check it against the factory gauge...

If you have a 180 or 195 thermostat, the gauge should read somewhere around the mid scale reading...after warm up...

It it comes up to three quarters of the gauge when idling,traffic,etc..Especially in hot weather where you are now...you can check the actual temp....

If you are running around 190 to 200 you are Ok...

If not, then isolate the problem...Fan clutch,thermostat,water pump, hoses soft and collapsing under acceration(lower hose), bugs or trash in radiator and condenser fins...


After you get it warmed up, bring the engine up to about 2000rpms or so and take a shop towel and throw at the front of the condenser in the front of the radiator...If you have good air flow, it should suck the towel up against it....IF not...blow out(from the back side always) the radiator and condenser...

This will tell you whether or not you're pulling enough air through...

Hope this helps you....I like to find out where the problem is before I spend the money.....Trav..

 

Too many guys just want to throw money and parts at a problem because they "thought that would fix it" and also too many guys ignore the computer (if applicable) I will never understand that....

 

Ditto on making sure you have a problem. As Trav said, the factory gauges are notorious for having problems. I put a mechanical gauge on. Also, if your radiator cap is bad you may lose coolant and then suck air back in as it cools. Then it gets warmer and pushes more out, sucks more air in, etc.

 

This is a general rule that works good on getting someone pointed in the right direction when troubleshooting cooling problems;

If it overheats in stop and go traffic, that is generally a air flow problem.

If it overheats on the highway, that is generally a coolant flow problem.

So using those rules, you are on the right track thinking it's the fan clutch, which would not give you good airflow if it were faulty.

 

Thanks for the advice. Just received the clutch today, but have a problem. When I opened the box, some of the internal fluid has leeched out of the clutch while it has been sitting upside down. I'm pretty annoyed that it wasn't marked "this side up".

Is some fluid loss ok or should I get it exchanged? The bag with supplied bolts was also quite slimey.

 

I would not run it. That's a failure mode with these clutches. The fluid is what drives the fan. If it all leaks out, then it's not going to work. If some has leaked out now, how long before all of it is gone? I would not use it.

 

Amen. The seal is obviously bad or it wouldn't have leaked. So, it is going to continue to leak.

 

Cheers, I've sent it straight back for replacement.

 

To check if your clutch fan is working run your engine 'put a blanket or towel over grille in front of radiator shut hood to hold blanket in place When your clutch fan locks in it should pull blanket in .