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.

 

[joshuawes1984]

An update.. Got it torn apart, and I found the culprit. The o-ring was not nicked, but it was pinched/flattened on one spot. I firmly believe that is the problem. Picking up a new o-ring shortly, and reinstalling!

Thanks everyone for the ideas, thoughts and support. You guys are awesome.

 

[D60]

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.

COMPLETELY different animal but the Murray pump for the Dodge Magnum engines is garbage. In contrast the less expensive MasterPro is GMB (clearly stamped on the pump).

The point is don't assume the Murray is good, but it sounds like you found your problem elsewhere.

I wouldn't add RTV and the next guy (like @Trav) will want to murder you. If you must, use anaerobic. Just pick up a tube while you're in O'Reilly

 

[The_Eric]

An update.. Got it torn apart, and I found the culprit. The o-ring was not nicked, but it was pinched/flattened on one spot. I firmly believe that is the problem. Picking up a new o-ring shortly, and reinstalling!

Thanks everyone for the ideas, thoughts and support. You guys are awesome.

Reading trough your thread, I was completely expecting this to be the problem.. I've gotten burned by dry o-rings once or twice in the past, so now I NEVER install a slip fit o-ring dry. The lubricant depends on the application - here I would use a silicone grease.

 

[joshuawes1984]

Everything is back together now. Picked up a new o-ring for $3.00, grabbed a small tube of water pump RTV, and some blue loctite.

The bore is surgical clean. I spent about 20 minutes on it with a very fine sandpaper and polished it up real nice. Brake cleaned, blew it out, dried it out. Also blew out the bolt holes and cleaned the bolts.

I did add a very thin layer of RTV to the o-ring. The new o-ring was just very slightly loose on the pump. Not sloppy loose, but enough I could turn it when installed. That prompted me to add the RTV to help it seal a little better. It seemed to slip in to place super easy. I guess the RTV also lubed it some.

Everything is torqued back to spec now. Now I’m dreading trying to get the stupid belt back on.

 

[grasscutter]

An update.. Got it torn apart, and I found the culprit. The o-ring was not nicked, but it was pinched/flattened on one spot. I firmly believe that is the problem. Picking up a new o-ring shortly, and reinstalling!

Thanks everyone for the ideas, thoughts and support. You guys are awesome.

I keep a tube of Dow Corning 1 1 1 around just for o-rings. It's a very high viscosity silicone grease. In your case, I would apply the grease to the o-ring before installing it into its groove and also apply the grease to whatever the mating surface for the o-ring is. The stuff is about $20 a tube but it's a large tube and very little is used at a time. I found out about the stuff from a water softener repairman who used it on plastic valves. Serious high quality grease that's completely water proof.