Hey all

I've got a 2016 F150 5.0L that started spewing coolant yesterday. It was very messy but I figured it was the water pump, either the shaft or the seal. I replaced the water pump with a new seal and all, got everything put back together but as soon as I started filling the reservoir it started pouring out again. Again, it's hard to determine where it's coming from but it's at least below the water pump. I double checked the bolts, checked all the hoses nearby, and I'm just not able to figure it out. It almost looks like it's coming from near the crankshaft pulley.
My best guess is maybe the o-ring got pinched on installing the new water pump but any other ideas of where next to look would be greatly appreciated!

 

Definitely check the water pump again. And while you're at it, do yourself the favor and replace that notorious coolant Y-connector hose. If it's not leaking already, it eventually will.

 

How many miles? I have 172K on my 13 5.0 and I have replaced they "y" adapter 2 times (once under warranty) and all of the other hoses and o-rings at least one time. Winter traditionally brings on the "leak" posts and replacing and greasing the fitting and o ring resolves the leaks.

 

This has just under 160k.
About 3 weeks ago the y connector had started leaking but it stopped in its own. It was about 5 degrees at the time so I didn't bother investigating further.
A friend suggested it might be a freeze plug which makes some sense. I'm just not sure where they're located so I'm going to have to spend time searching. Do you know if there are any located in the front of the block near the pulleys??

 

THere are posts here that show that the o rings go flat. Needs to be replaced. Plan to replace all hoses and drain radiator on the truck with that many miles. JMO

 

That's the ultimate plan, but first I have to figure out where it's leaking on the block. I really don't think it's the water pump o ring just based on observation.

 

You could use a dye product

 

Well, turned out to be a pinched o-ring. Got a new o ring, greased it up a bit this time, and made sure to push it on straight. Holding tight now! What a mess...

 

Excellent!