J'sFX4.5.0

I removed the tank and saw no evidence that there was any damage to the tank side what so ever no cracks or imperfections that could camage the O ring. (It's also metal lined). I Replaced the hose and it still leaked. I used RVT and it sealed it nicely. Put a fat bead on the reservoir side and plugged her in. I used Loctite Black Flexible RVT. Let it cure for 24 hours then out her back on. I'll also add that I put my old hose back on for this project just in case it didn't work I would still have a new hose to go with a new reservoir!. It's been a week now and no leaks. I was really weiry about "jerry rigging" somthing on my new truck. Especially motor/cooling system. But I know how well RVT works and I'm all for saving a buck! Or $250 in this case.

rkeller

The split was in the seam and hard to find because it only leaked when the tank was pressurized.
You can see some coolant residue and see the open seem in the close up.

rkeller

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rkeller

Ford let me know this was not covered under the extended warranty.
Even if it was there is a large up front payment so even if a part is covered under the extended warranty the min. charge may be more than the part. That was the case in my turn signal switch as well.

J'sFX4.5.0

I'm pretty sure mine was leaking in the fitting it's self not the actual reservoir. The RVT did hold up well for a month or so and now I'm back to the same problem. Perhaps I didn't put enough on to make a good seal. Anyways it's back to pulling her apart. Good ol' fords

benchwarmer4203

I noticed that you used different RTV than I did when I fixed mine. I used Permatex red hi-temp. Not sure if that's the difference or not, though; because I replaced the tank, hose, and then added the RTV for extra insurance.

J'sFX4.5.0

Ya the stuff I used is oil resistant and flexible. Got it from a buddy that works on heavy equipment. Said it should work better because it's industrial grade stuff. Apparently not the right application.

WSB

My 2011 F150, 5.0 has always had a slight whiff of antifreeze since new , after 39,000
miles a small puddle appeared under the power steering control box, after reading the posts , I found the lower pressure hose on the expasion tank wet, I removed cleaned and inspected the tank and hose(no cracks), reinstalled with a fuel sealant called Titeseal, (no success) I ordered a replacement hose and will retry, short of using an epoxy two part fuel tank sealant to permently attach the hose to the tank, Bill

J'sFX4.5.0

I made the mistake of paying for a new hose and still leaks, I have since then put the old one back one tried the RVT black silicone, it leaked after a month so I tried using a silicone type of wrapp adhesive. It's extremely stretchy and rated for high tempature and resistant to chemicals. (Bought from home depo in plumbing department for $10) since then I have no leaks (2 months and counting) good luck to anyone else with this isse!

WSB

Thanks for your advise , The new hose silicone seal appears to be coated with silicone dielectric grease, I'll probably buy a new tank to resolve this before it gets cold and have to deal with coolant fluid leaks , the stuff seems to corrode everthing it touches, Bill