So is the water pump being driven by the fan pulley? Because that's exactly where it's leaking from. At least it's cheaper then a new rad. How do I go about replacing it? Thanks.

 

yes it is. u must remove the belt and the fan shround and ur fan clutch then hoses and the water pump.

 

water pump replacement how-to

http://www.gmtruckhq.com/?q=Water_Pu..._vin_code.html

Also, the replacement water pump will likely be a raw casting. To avoid ugly surface rust a good coat of engine enamel will work well.

 

It's not hard to replace the water pump - I did it on my 98 2 years ago. You will need one very large socket (1 3/4 inch if I recall) and a large breaker bar or ratchet to remove/replace the fan though.

 

Removing the fan is the biggest obstacle. Here is a picture I drew to show how removal is easier.

 

Awesome! Thanks for all the info. I'm picking up a pump first thing in the morning. What's the best way to flush out my block and heater core? Might as well do it. Thanks again.

 

You can use a garden hose, but don't use too much pressure on the heater core, they're somewhat sensitive to pressure as many have found out. They're also not easy to replace; ask me how I know. When flushing the heater core, be sure to back flush it, which I believe is putting the hose to the larger 3/4" pipe. Also, once your system is completely flushed, refill and drain with hose water (at least) once after a heating and cooling cycle (or more), then drain again and refill with DISTILLED water and coolant mixture.

 

Ok, where is this nut on the fan that I put a wrench onto? The only place I can get a wrench onto is the shaft in between the pulley and the clutch. Is that what I turn? Because an 18" wrench is to thick to fit on the shaft because the nut on the pulley stick out to far. I got some vice grips on there but it's not doing much. Any advice?

 

Get a smaller crescent wrench. I bought either a 10 or 12" wrench for this job.

 

Alright, I finally got it with the vice grips. Good times. What year is your truck Bud? Mine's a 95 and the shaft is round, and every other picture I've seen of later models have a square shaft, and my fan blades are metal. Is it going to be this tedious putting it back on?