Due to two months of constant rain, and to having more pressing matters to attend to during the few less-rainy moments, I just this evening got around to "SUMMERIZING" our trucks.

I removed the winter-time fan-clutches and installed the summertime "pinned" direct-drive clutches.

I love to hear the fans over the roar of the engine, sounding like a turbo-jet winding up; it sure is reassuring to know that the fan is doing it's optimum-best, with no wimpy clutch to slow it down.

I also remembered to close the ball-valve in the heater-hose of my truck, thus stopping the flow of HOT coolant into the IN-CAB air system.

The wife's truck has some kind of vacuum-operated gizmo that is supposed to stop the flow of coolant into the heater-core.

My understanding is that, when A/C is selected, a vacuum signal tells this valve to close.

How do I know if this vacuum valve is functioning ??

Can I see it operate, while someone in the cab operates the switch ??

Thanks.

 

Yes but only on "max" AC

 

BK,

Do you have any pics of your manual valve ? I think I am going to go that route on mine.

 

What does MAX A/C do different from A/C ?

 

Turns off the coolant valve, and recirculates the air from the cab instead of pulling outside air.

 

Does that kill your fuel mileage?

 

Sorry, no pictures yet.

This is on my Ford/Cummins; and, due to differences in engine-bay design, I didn't utilize the steel coolant tubes; but instead, in the upper hose position, I installed a pipe nipple in that port, then an elbow, then another nipple, then ball-valve, then 5/8-barb into the hose.

The valve is immediately behind and above the alternator.

On the wife's ALL DODGE/Cummins truck, I am going to take one of the steel tubes that I didn't use on my truck, cut it in two, splice in a ball-valve, paint it nice and pretty, then replace the tube on her truck with the valved tube.

That silly vacuum-gate may or may not work; I KNOW whether or not the ball-valve is working.





On all of our trucks, I can feel no loss of power and no noticable change in mileage whatsoever.

If the engine can muscle sixteen big Charolais cows up Russell Creek Hill and not take a short breath, it isn't gonna notice a silly little old fan.

 

did you fab those pinned clutches?

 

YES SIR, I did.

The first clutch I ever pinned was on an old gas-burner Bronco.

At that time, I did not know there was such a thing as an un-permanently-connected fan.

The fan quit turning and the engine started heating up; a replacement fan-clutch cost more than I paid for the Bronco, so I thought my way through the dilemna, drilled entirely through the clutch-housing, installed a Grade-8 bolt/nut, and it was still running like that ten years later when I finally let someone else have it.


When the shop that completely rebuilt the entire A/C system on the wife's truck installed the fourth NAPA fan-clutch in two days time, I told them to dig the old one out of the dumpster, I took it home, drilled/tapped four holes through the face, loc-tited and safety-wired Grade-8 bolts that pressed the internals firmly together, stuck it on the engine, and problem solved for good.

The guys at the A/C shop were amazed.