2010 Ford Fusion - Water Pump

[joshuawes1984]

I have a 2010 Ford Fusion with the 2.5L in it. Recently I replaced the water pump with a new unit. The idler was squeaking awful, so I figured while I was in there, I might as well replace the WP, belt, etc. For context, the WP design has an O-ring seal on the pump body that inserts into a bore in the side of the engine. It isn't like one of the WP's that has a seal on the face of the flange.

Anyway, after I installed the new pump and got everything buttoned back up; I noticed it was weeping and leaking coolant out the bottom. I verified it wasn't leaking from the pump weep hole. The coolant was coming from the flange where it mates to the engine. I torqued the bolts up a little tighter (I had them pretty snug, but I guess not tight enough) and that stopped the seeping for quite a while. Now, it's seeping again and has leaked out all of the coolant that was in the reservoir. Completely bone dry, empty. It's a thousand wonders I didn't overheat the car.

During my inspection, I noticed that the WP bolts were no longer as tight as I initially tightened them, which I found strange. When I reinstalled the bolts, I didn't add any Loctite or sealant to the threads.

Also, when I went to tighten the bolts again, I noticed a little bit of coolant actually squeezed and seeped out from the mating surface confirming my suspicions that my leak is coming from the water pump.

My questions are as follows:

1. Should I just retorque the bolts properly and keep an eye on it?
2. Should I completely remove the bolts, clean them, blow out their holes, and add a little blue Loctite before reinstalling?
3. Should I completely remove the new WP, add a thin layer of RTV around the O-ring sealing area, and then reinstall with some blue Loctite on the bolts?

I don't mind at all doing number 3, but I've always read that these O-ring seals are meant to be assembled "dry" and to not use any kind of RTV on them. Obviously, I don't want to take any half measures either and make sure this thing never leaks again.

 

[D60]

I have to wonder if the pump is somehow machined incorrectly or the o-ring got nicked etc

Otherwise if you reuse it I might try some Nylog White

 

[joshuawes1984]

I have to wonder if the pump is somehow machined incorrectly or the o-ring got nicked etc

Otherwise if you reuse it I might try some Nylog White

I really can't see how I'd have nicked it. I took time to clean the bore and wetted the o-ring before installing the new pump. I guess it's plausible and might be worth pulling it just to verify.

 

[D60]

I really can't see how I'd have nicked it. I took time to clean the bore and wetted the o-ring before installing the new pump. I guess it's plausible and might be worth pulling it just to verify.

These o-ringed pumps are largely idiot proof so there may be something wrong with the o-ring size/section width. You shouldn't have a leak so something ain't right. Also not sure why bolts would back out. I've never experienced water pump bolts backing out.

 

[joshuawes1984]

These o-ringed pumps are largely idiot proof so there may be something wrong with the o-ring size/section width. You shouldn't have a leak so something ain't right. Also not sure why bolts would back out. I've never experienced water pump bolts backing out.

I wouldn't say they "backed out", just, they weren't as tight as I thought I tightened them. Maybe I didn't snug them enough, I thought I did though.

O'Reilly's has just the replacement o-ring seal for $3.00, I think I'm going to pull the pump, replace the o-ring, and add a little bit of RTV just to help seal it once it's in place. I'm undecided on a little dab of blue Loctite on the bolt threads though..

 

[mazdamonky]

I have installed quite a few of these. I made the mistake of putting one on "dry" and had the oring end up leaking. I have made sure I use some o ring grease or silicone spray ever since. I haven't had a problem since. make sure you wipe the mating surface down and lubricate the o ring somehow.

 

[Drifter]

I say step 1.. Re-tighten and recheck soon. If they loosen again go to Step 2. By chance are these one time use bolts ? And are they hard to access ?

 

[joshuawes1984]

I say step 1.. Re-tighten and recheck soon. If they loosen again go to Step 2. By chance are these one time use bolts ? And are they hard to access ?

I'm unsure if they're one time use or not. Two of the bolts are easy with a 8MM wrench. The third has to be accessed through the fender well, and it is a PITA., ha.

 

[wtd]

I would torque the bolts to factory specs and use some blue locktite if it makes you feel better. I use Superlube o-ring lubricant on o-rings so that they go in easier and smoother and so they don't roll during the install.
https://www.amazon.com/Super-Lube-5...4437057&sprefix=superlube,aps,216&sr=8-1&th=1

 

[Hirev]

Do the water pump bolts go into blind holes or thru holes?

 

[joshuawes1984]

Do the water pump bolts go into blind holes or thru holes?

I'm pretty sure they're blind holes. Not 100% sure, but I'm assuming.

 

[Hirev]

Ok might have to get a new O ring and see if that helps.

 

[oilboy123]

I did my Focus 2.0 awhile back. It seems like pretty much the same pump. Or very close. I used the antifreeze on the oring. Also wiped everything to make sure no burrs etc. I put a Motorcraft pump on. The holes were blind. I would pony up for the Motorcraft myself. Or try an oring. But I would not want to do the job 3 times.......

Like mentioned check oring for cut, and the water pump oring surface on the block for a burr. Compare orings on old pump and new. Like mentioned could be oring groove on pump is wrong. Or oring not correct. What brand pump dare I ask? I'm going to do a pump on my daughter's 2.0 Edge. I will be going Motorcraft water pump.

 

[joshuawes1984]

I did my Focus 2.0 awhile back. It seems like pretty much the same pump. Or very close. I used the antifreeze on the oring. Also wiped everything to make sure no burrs etc. I put a Motorcraft pump on. The holes were blind. I would pony up for the Motorcraft myself. Or try an oring. But I would not want to do the job 3 times.......

Like mentioned check oring for cut, and the water pump oring surface on the block for a burr. Compare orings on old pump and new. Like mentioned could be oring groove on pump is wrong. Or oring not correct. What brand pump dare I ask? I'm going to do a pump on my daughter's 2.0 Edge. I will be going Motorcraft water pump.

I wetted mine with some coolant/water too before reinserting it. Maybe there was a burr or something it caught on that I missed, but I took a piece of fine grit sandpaper and wiped inside the bore a bit and tried to clean it good before reinstalling.

Yeah, I'm not looking forward to digging back in it tomorrow in the heat, but I guess that's what's going to happen. I bought a Murray pump from O-Reilly's locally. It seemed to be of good quality. I've used Murray pumps on all of my other vehicles too and am having good luck with them so far.

I think right now the plan is to get it all pulled apart, get a replacement O-ring, super clean and inspect the bore, blow out the bolt holes, clean the bolts, and add a thin coat of RTV to the O-ring and pump flange before reassembling with a little dab of blue Loctite on the bolts. I don't think I'm going to coat the threads, but I do want to add a little something to make sure once I torque them correctly, they stay torqued.

 

[dnewton3]

The only "seal" is that o-ring to the bore. The flange face surface and bolts are merely a mechanism to facilitate the location and function of the pump; they do nothing directly for sealing the coolant system.

It is very crucial to clean the sealing bore well before installing the new pump; ANY debris (rust, etc, pitting) in that bore can cause a leak. Also, as others have said, the o-ring should be checked for nicks, cuts, etc. It's not uncommon for people to nick the o-ring upon installation; it can be pinched or twisted if not careful. Adding a small bit of grease to lube the o-ring and bore is generally considered a good idea.

Ford used that design in a LOT of engines; all the Mod-motors, and about every in-line 4 for more than two decades. It's a ubiquitous design, and serves quite well when done properly.