About a month and a half ago, I used the A/C for the first time this season, and it caused a bit of a problem. I parked it for 3 hours and found a puddle of coolant around my truck. So I found the hole in the rad, patched it and thought all was well, but apparently it's not. Every time I use the A/C, or sometimes when the weather is above 77 F (25 C if you're from Canada, like me), I get a loud vibration coming from what we think is the fan clutch. There's a bit of play, so it seems like the fan clutch is lose, but even after we've tightened it, it's still vibrating.

When we patched it, we did a rad flush, and the bastard that owned my truck before me wasn't using ionized water (you wouldn't believe the **** that came out of it). I'm recharging the A/C on Friday, which needs to be done anyway, and we're planning on replacing the patched rad before the winter season, just waiting on parts. But my question is, are we overlooking something key here? Should we replace the water pump before the rad (thought maybe it was causing the vibration)? Maybe somebody out there has had the same issue?

Oh and just a heads up, the engine temp has never been high, except on that day where the rad blew. Which makes me believe that it's not the water pump. Sorry if I'm rambling a tonne, I'm just new to the truck thing, and it would kill me if mine just died all of a sudden.

 

The fan clutch has its own bearing and it can get sloppy. There shouldn't be any play. The water pump bearing can also wear. Again, no play.

Grab the fan blade and move it forward and backward to check for play.

It can be hard to tell which is causing the problem.