I was in the process of chasing a coolant leak. I had the week off from work, the weather is decent for this time of year, and my truck needed attention... the leak was a drip on the ground toward the front of the engine while idling. No hoses or radiator leaks were apparent. So I picked up a Gates water pump at the local parts store I deal with ( not the Zone!!) Well you all know the "walk in the park" changing a water pump on a 5.9l (360 cid) gas engine can be!!!
The water pump job went well, I went with all new hoses clamps, and fan clutch as well, as my clutch fan was not clutching any more!! I got changing the thermostat and when I removed the hose outlet, I discovered the manifold mating surface was corroded and HEAVILY pitted where the gasket mating surface is!
I am having difficulties uploading a pic, but I'll keep trying.
Mike

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Here is a pic of the manifold

 

yeah that looks pretty bad, mine did not look that bad although the water neck did. how many miles? is it good though, no leaks? my timing chain cover (that one housing behind the water pump) was eaten up good in couple places but i managed to seal it back up with no leaks, suprisingly. my last water pump was from the dealer so hopefully it will last longer than what was previously used. I personally like autozone but there are some parts i would not buy from any big box store.

 

Yeah, my bypass inlet was corroded too. It happens. Try to sand it smooth again and reseal. You'll be fine!

 

235,000+ miles on chassis, 360 gas engine is what was in truck from factory, not sure if THIS is the original, but probably is. Replaced the passenger side cylinder head with a known good running used one at around 212 thou on the clock.
I had luck getting the water outlet to seal up ... so far so good using , in most opinions as a rather EXTREME method , but hey, it's working so sar! I hadn't posted because I wanted to run it for a while before I posted it was leak free!!!

When I applied the RTV, I was Xtremely carefull NOT to get it in on the Thermostat

 

Too bad I didn't see this sooner, or I would have recommended you refilling your vehicle's cooling system with a couple of gallons of vinegar and topped off with distilled water. Then, let the vehicle sit for a weekend before firing it up for about 15 minutes and then drain. That would have cleaned up a lot of gunk in that engine.

 

Nice in theory, but no room to work the manifold real smooth! I got it the best I could, with what I had on hand

 

Thanks GaryL, I used an over the counter flush, replaced waterpump, all hoses and refilled with a 75% Prestone anti freeze blend,
The issue was the corroded mating surface of the water outlet to intake manifold actually, the flush and refill went without a hitch

 

Not theory. I did it during the t-chain install so everything was removed.

 

��, good,glad that worked for ya! I didn't feel I could get in at it , so I went about fixing it how I did. So far so good!