[Nathanstrick96]

I discovered a leak last November. The leak ONLY occurs under pressure and when the engine is hot. Coolant does not pool underneath the car when engine is not running. That being said, when I discovered the leak last November, I heard squeaking. I just automatically assumed it was the water pump. It was time to replace the pump, so I just replaced the pump and the gasket. I reassembled the system. As soon as I filled the coolant, I noticed coolant draining down the coolant valley. I used silicone gasket sealer to seal the water inlet and stopped that leak. The thermostat and o ring were also replaced. I finally finished all the tasks and took her out for a test drive. Still the same coolant leak as before. Rented a pressure tester and discovered a large crack in the top radiator tank. Replaced the radiator as well to fix the leak. Last evening, I took it for a test drive. Still the same leak. I was pretty upset at that point. So I just let it sit until this morning. I took a quick drive to get it hot so that it would leak again. I put the pressure tester on it when it was hot and coolant is pouring from the passenger side on the bottom of the engine area. I cannot tell where the leak is coming from, but it seems to be originating just above or behind the alternator. It is leaking onto the alternator pulley and being flung all over the engine compartment via the serpentine belt. I’m about to take it to a mechanic, but I figured I would get some opinions here first. Approx 195,000 miles

 

[baltimorebirds2]

Did you try radiator hoses?

 

[Nathanstrick96]

Did you try radiator hoses?

Yes. Not coming from those. I read on here that maybe the cast aluminum forms pits from corrosion and that I should have used RTA with the water pump gasket. I may just take it apart one more time.

 

[5 Speed]

I recommend that you pull the hoses and run a scotch bright pad around all the fittings where the hoses clamp because over time they build up deposits and when you put an older hose back on it has a good chance of not sitting exactly like before and leaking. I recommend replacing your hoses every time you do your timing belts just as a good practice. The hoses harden over time and can leak at the fittings. If you don't replace the hoses cleaning their inside mating surfaces is a good practice.

 

[Nathanstrick96]

I recommend that you pull the hoses and run a scotch bright pad around all the fittings where the hoses clamp because over time they build up deposits and when you put an older hose back on it has a good chance of not sitting exactly like before and leaking. I recommend replacing your hoses every time you do your timing belts just as a good practice. The hoses harden over time and can leak at the fittings. If you don't replace the hoses cleaning their inside mating surfaces is a good practice.

Well, I found the issue on Friday. Total and complete lack of competence and being thorough on my end. I pressure tested again Friday evening, trying to find the leak. It was hidden from me, it seems the hose that was put in the truck before I bought it, wasn’t cut to length. It was slightly too long and the lower hose was rubbing up against the serpentine belt. I replaced and solved the issue. I didn’t think to inspect the hoses when I removed them all, or to move them when pressure testing. Definitely should have been the first thing I did. The leak was difficult to see because it wasn’t spraying visibly from the hose. It was pressed up against the belt and running down the belt to drain off the nearest pulley.

 

[Jonesy]

Thanks for the update . . .