On dad's 01 f350 we noticed a small puddle of antifreeze a few days ago. We located the leak on the main line on the bottom of the water pump. It looks to be a plate where the hose attaches that bolts on with 2 10mm bolts. Is there an o ring behind that? Are those common to leak?

 

Yes, there is an o-ring there. Be prepared to buy a new lower neck though, they tend to be corroded and don't seal so well after being removed.

The P/N in the picture is an International number, but you can get it at a Ford dealer too.

 

Pretty sure the ford # is F81Z-8255-AA. Ken's right about the corrosion and junk. I was able to clean mine, and used plumbers lube on the o-ring and no problems.

 

The truck just turned over 100000, so do you think i should buy new parts or try to clean the old one?

 

The fellas above have you on the right track.That is low miles for these trucks but like they said,use your best judgement.Clean the parts up and see if you find pitting and corrosion.If so,replace it.You will be better off in the long run.
Beings you are going to loose coolant.It might be a good time to flush and fill with the Extended Life Coolant.No matter if you use the green or red,the water you add back should be DI or Distilled water.Do not use tap water.

 

I think I'd just replace the o-ring. The extension neck on my pump was in good condition after 230k miles so I just re-used it. I think I got another 20k before the front seal began leaking on the pump itself...

 

I agree with Greg. Clean up the lower neck and water pump inlet, replace o-ring. When was the antifreeze changed or tested last? It would be a good time to up-grade hoses though(around the belt,...)

 

The truck still has factory fluids in it (except for oil of course)

 

I know that this thread is a little old, but I have the same problem and a couple of questions.

1. Is the O-Ring the same one used on the Thermostat housing?
2. At 180K miles should I be expecting to replace the waterpump soon?
3. I take it that any Radiator "Stop Leak" as a short term solution is a bad idea?

Thanks in advance
Dave Morris

 

I would plan on replacing the waterpump while you are at home with all the tools and maybe a garage. It is always easier that way.

Radiator stop leak is not a good option IMO. It doesn't know the difference between a leak and a small orifice. Therefore it can clog up your system and make it less effective.

 

No. It's a much larger o-ring.

Make sure the leak isn't from the water pump shaft seal weep hole. It can drip down and appear to be a leak of the outlet pipe o-ring.

Here you can see the discoloration from a weep hole leak. Coolant leaking from weep hole behind water pump pulley and down the front cover.



Weep hole.

 

I am not sure if this is a "weep hole" situation or the oring leaking on the lower neck? I cant get a good shot of the weep hole. I attached a few pics of the leak and the hoses/bottom of pump. I can't see any leaks from the top of the truck. I noticed a faint antifreeze smell when I was running errands today. I dunno what triggered this....just an old truck and thats how it goes I suppose. Check out these pics and lemme know what you think it might be.





Small puddle

 

I would lean to replacing the whole pump, I just got to replace mine went cheap, Autozone loaned me the clutch fan removal tool.

 

Errrrr...? Are you suggesting I replace the entire waterpump because the lower neck is leaking a little bit?

 

Had to replace my lower neck o-ring at 230k, and I was able to reuse the lower neck, so I hope it's the same for you, not too bad of a job. For my truck, the O-ring part number was actually identical to the thermostat O-ring PN, but some others are different it looks like. Good luck to ya.