fuel leak problem
Lead Driver
Joined: Dec 2020
Posts: 8,640
Likes: 2,435
What part # do you see? This doesn't need to be difficult. Also, the most recent version of the fuel filter set was not out in 2021, so why the claim that it's unique to this newest version?
Lead Driver
Joined: Nov 2005
Posts: 8,477
Likes: 4,972
All of those PDF diagrams are identical, all showing FD4625AA filter number, so the cold weather bypass is not new and unique to the new FD4647 filter.
And, the way the text reads says to me that the cold weather fuel bypass just recirculates fuel back to the engine that would otherwise be the fuel returned to the tank, not unfiltered fuel.
I guarantee you that I am surely not worried about it.
And, the way the text reads says to me that the cold weather fuel bypass just recirculates fuel back to the engine that would otherwise be the fuel returned to the tank, not unfiltered fuel.
I guarantee you that I am surely not worried about it.
Cargo Master
Joined: Jul 2011
Posts: 2,675
Likes: 979
From: Walpole, MA
OP, looks like you had a top filter crack. Not any unheard of event, luckily you caught it before anything really bad happened.
The NHTSA dinged ford for it, they introduced a new filter with additional ribbing to try to address this.
https://normantaylor.com/blog/nhtsa-...el-leak-risks/
IIRC the bypass showed up in 2021 or 2022. There is no fuel that is recirculated to the upper filter. The rear (towards the firewall) 1/2 QC is supply to the filter, the 12mm (middle) QC is filtered fuel to the HPFP and the 5/16 QC (front, small on the 2017+ trucks) is return from the filter, not the HPFP. If you disconnect that fitting with the truck running the fuel comes out the filter, not the hose. Not sure what temp/pressure differential the bypass is supposed to kick on.
There is a thermostat valve back on the top of the water separator on the return side. If the fuel is too cold, it is sent through the water separator and back through the LPFP back to the upper filter. I do not know what temperature that valve opens at.
https://www.forddoctorsdts.com/forum...dentification/
The NHTSA dinged ford for it, they introduced a new filter with additional ribbing to try to address this.
https://normantaylor.com/blog/nhtsa-...el-leak-risks/
All of those PDF diagrams are identical, all showing FD4625AA filter number, so the cold weather bypass is not new and unique to the new FD4647 filter.
And, the way the text reads says to me that the cold weather fuel bypass just recirculates fuel back to the engine that would otherwise be the fuel returned to the tank, not unfiltered fuel.
I guarantee you that I am surely not worried about it.
And, the way the text reads says to me that the cold weather fuel bypass just recirculates fuel back to the engine that would otherwise be the fuel returned to the tank, not unfiltered fuel.
I guarantee you that I am surely not worried about it.
There is a thermostat valve back on the top of the water separator on the return side. If the fuel is too cold, it is sent through the water separator and back through the LPFP back to the upper filter. I do not know what temperature that valve opens at.
https://www.forddoctorsdts.com/forum...dentification/
Lead Driver
Joined: Nov 2005
Posts: 8,477
Likes: 4,972
Originally Posted by Ltngdrvr
All of those PDF diagrams are identical, all showing FD4625AA filter number, so the cold weather bypass is not new and unique to the new FD4647 filter.
And, the way the text reads says to me that the cold weather fuel bypass just recirculates fuel back to the engine that would otherwise be the fuel returned to the tank, not unfiltered fuel.
I guarantee you that I am surely not worried about it.
All of those PDF diagrams are identical, all showing FD4625AA filter number, so the cold weather bypass is not new and unique to the new FD4647 filter.
And, the way the text reads says to me that the cold weather fuel bypass just recirculates fuel back to the engine that would otherwise be the fuel returned to the tank, not unfiltered fuel.
I guarantee you that I am surely not worried about it.
IIRC the bypass showed up in 2021 or 2022. There is no fuel that is recirculated to the upper filter. The rear (towards the firewall) 1/2 QC is supply to the filter, the 12mm (middle) QC is filtered fuel to the HPFP and the 5/16 QC (front, small on the 2017+ trucks) is return from the filter, not the HPFP. If you disconnect that fitting with the truck running the fuel comes out the filter, not the hose. Not sure what temp/pressure differential the bypass is supposed to kick on.
There is a thermostat valve back on the top of the water separator on the return side. If the fuel is too cold, it is sent through the water separator and back through the LPFP back to the upper filter. I do not know what temperature that valve opens at.
https://www.forddoctorsdts.com/forum...dentification/
There is a thermostat valve back on the top of the water separator on the return side. If the fuel is too cold, it is sent through the water separator and back through the LPFP back to the upper filter. I do not know what temperature that valve opens at.
https://www.forddoctorsdts.com/forum...dentification/
Cargo Master
Joined: Jul 2011
Posts: 2,675
Likes: 979
From: Walpole, MA
Yes, it says that but there isn't a point where the fuel is recirculated downstream of the secondary filter. They could be referring to the valve at the top of the water separator.
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