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6.7L Won't Start, Fuel Filter Change

87K views 14 replies 10 participants last post by  Stroking it 
#1 ·
I was changing the fuel filters on my 2012 F350 6.7 and apparently my guy did not secure the low pressure filter housing fully when he put it back on, even with me asking to be sure he cranked it until it stopped. He confirmed he did, but he did not. (Yes, will never turn a wrench for me again)

So now there is a ton of air in the fuel system, and can't seem to find the schrade valve.

I have a new low pressure filter and o ring to put on, and I expect - but don't know - that the leak is from there.

Once I have that done, is there a way to bleed the fuel system other than cycling the key tons of times? I have done it well over 100 times thus far...

Regards and thanks

DB
 
#2 ·
Once you replace the filters and oring, the only way to purge the air is to cycle the key. I do it a full 6-8 times, each time listening for the pump to stop, but also for the sound of air to be gone as well. Use a little motor oil on the oring to make it slippery, and turn it slowly with the wrench, until it hits the stop. There is a plastic stop, and if you don't make it that far, you will have a air leak. Another possible one is often the oring can get bunched up and cause the air leak. I'd also check the quick disconnect connections for the under-hood filter. Maybe remove them, and reseat them again, although I haven't heard of many issues there.

Just to be clear, you aren't seeing any actual fuel leaking, either under the truck, or under the hood, correct?
 
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#3 ·
Correct. No fuel was leaking.

I noticed I had less than a quarter tank of gas. I got ten gallons to put it over half a tank. I also bought a new fuel filter so I could re-do the entire lower since the guy did that one. Basically, I didn't trust any step he did. I replaced the lower very carefully. Cycled the key 8 times, no luck.

Cycled the key another 15 times, and finally got a start after a few seconds of struggling.

I think the lower was just done improperly, the filter was not really seated on the filter cover when he put it in I think, and when I tried to redo it yesterday before buying a new filter, the filter would not seat on the housing before getting put back on. There was some play. I have no clue what he did to screw that up or if that even had any effect, but it is running now, so phew!

Hopefully this can help some other poor s.o.b. out there at some point.

Thanks guys!

DB
 
#4 ·
Great news!
 
#5 ·
For a system that has turned into such a critical element you would think the engineering and QA would have been better. This shouldn't be such an issue with today's technology and materials.
 
#6 ·
Actually, I don't think that filter is all that much of an issue frankly. You snap the filter into the cap. You REPLACE and LUBRICATE the sealing surface of the cap and the green o-ring supplied with the filter and then slowly tighten the cap until it hits the stop. Not too tough in my opinion... but I am just a dealership idiot.
 
#7 · (Edited by Moderator)
Despite all the headaches I had to endure, the only complaint I have is not with the engineering but with the lack of documentation. I bought the access to the Ford docs via alldatadiy.com and there is absolutely no information on troubleshooting procedures on this simple but critical task. Two sentences would be all that's needed, but I understand that's not needed for the audience the documentation is intended for.

The problem in my case is that the procedure is pretty damn monkey proof, but apparently my monkey was extra special. Couldn't even tell if it had hit a stop or not when tightening the cap back on. I just don't get how that's possible, it was as easy as anything I've ever turned a wrench on. I own and run multiple businesses in multiple industries, and I am absolutely shocked as to how little basic knowledge kids coming into simple jobs just don't know. I try to teach and mentor, but it doesn't seem to work very well.

Another example of "Don't Trust ANYone to Work On Your Truck". I was two feet away and asked him twice to be absolutely sure it was on all the way. It wasn't.

Friends don't let friends get Monkeyed.

Regards,

DB

PS: I do have an engineering complaint about the 6.7, the facking dipstick. Seriously?
 
#8 ·
There are plenty of people you can trust with your truck. You just need to find one. ;) I think that people on these forums toss around generalities way too loosely and unfortunately you really only read about the negative experiences for the most part. I will completely agree with you on the dipsticks on these engines. Unless you are 6'+ they are difficult to reach AND try adding fluid to the transmission with any funnel... without bending/propping it up.
 
#11 ·
We changed the filters on my Dad's 2012 and had the same problem. He didnt buy an OEM filter and the only way we could get it to prime was to re-use the OEM oring.
 
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#13 ·
If you coat the canister threads and the O ring with vaseline you can install the canister with your hands easily until it stops. It NEVER needs to be tighter than that. The O ring has ZERO need for any torque on the canister and it is not going to vibrate off. The same for oil filter caps and the fuel filter caps on any of the 7.3. 6.0, or 6.4 engines. Friends don't let friends over-torque feces (substitute the 4 letter word beginning with "s", ending with "t" and containing "h" and "i".
 
#14 ·
It is recommended that one use clean engine oil to lube the o-ring. Then make sure the cup is tightened until the stops on the cup and pump meet before priming the fuel system with the 6 key turns for 30 seconds each.
 
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