Fuel filter head leak fun

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

It seems that there's now a minor fuel leak from the fuel filter head. As best I can tell, it appears to be coming from around the 6 o'clock position on the flat face behind the plunger, and has probably started within the last 3 days or so.

This is the revised design head with the blue plug. I'm not having much luck finding anything related to this type of failure happening before - at least, not on the revised head.

Has anyone else experienced this? My guess is that installing the in-tank pump showed up an existing weak spot in the filter head, but I'm concerned that if I replace (or repair) the cause of the leak, it'll just come back again due to the pressurised fuel system.

WWDiesel · **Posted:** Thu Sep 19, 2019 3:45 pm

casm wrote:

It seems that there's now a minor fuel leak from the fuel filter head. As best I can tell, it appears to be coming from around the 6 o'clock position on the flat face behind the plunger, and has probably started within the last 3 days or so.
This is the revised design head with the blue plug. I'm not having much luck finding anything related to this type of failure happening before - at least, not on the revised head.
Has anyone else experienced this? My guess is that installing the in-tank pump showed up an existing weak spot in the filter head, but I'm concerned that if I replace (or repair) the cause of the leak, it'll just come back again due to the pressurised fuel system.

Not sure there is any serviceable parts behind that plunger???

Running totally on memory, can be fuzzy at times!
but I do remember that the fuel filter head is two piece or more like a stacked sandwich.
If you remove the assembly from the fire wall, then remove the fuel filter, you will see the steel fitting that the filter screws onto.
If you unscrew this fitting, the filter head will come apart and there either some gaskets or a big "O" ring between the parts that can be renewed.
Cannot remember for sure which, others on here may remember?

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

WWDiesel wrote:

Running totally on memory, can be fuzzy at times!
but I do remember that the fuel filter head is two piece or more like a stacked sandwich.
If you remove the assembly from the fire wall, then remove the fuel filter, you will see the steel fitting that the filter screws onto.
If you unscrew this fitting, the filter head will come apart and there either some gaskets or a big "O" ring between the parts that can be renewed.
Cannot remember for sure which, others on here may remember?

Took another look. It appears as though the leak is coming from the plunger shaft, then running down from there. It's a pretty decent leak: cleaned it up, made a six mile round-trip, and it was wet again. My guess is that a seal on the shaft has let go.

Looking at the assembly, I can see what appear to be four indents used to screw down the bezel behind the plunger. However, they're designed to be a one-way fit - the bezel goes on, but isn't really removable. The indents are designed to allow a tool to screw it down, but if you try to unscrew it, ramps in the indents will cause any tool inserted into them to just slide up and out. I've seen this sort of thing on security screws / bolts before.

Unless whatever is allowing the fuel to leak out is accessible once the two halves of the sandwich are separated, it's probably going to be new filter head time. Grrr.

WWDiesel · **Posted:** Thu Sep 19, 2019 11:24 pm

casm wrote:

Took another look. It appears as though the leak is coming from the plunger shaft, then running down from there. It's a pretty decent leak: cleaned it up, made a six mile round-trip, and it was wet again. My guess is that a seal on the shaft has let go.
Looking at the assembly, I can see what appear to be four indents used to screw down the bezel behind the plunger. However, they're designed to be a one-way fit - the bezel goes on, but isn't really removable. The indents are designed to allow a tool to screw it down, but if you try to unscrew it, ramps in the indents will cause any tool inserted into them to just slide up and out. I've seen this sort of thing on security screws / bolts before.
Unless whatever is allowing the fuel to leak out is accessible once the two halves of the sandwich are separated, it's probably going to be new filter head time. Grrr.

That's a real bummer! :banghead:

Looks like Rock Auto has the best price for the 68043089AA replacement unit.
https://www.rockauto.com/en/parts/mopar ... ilter,6216

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

WWDiesel wrote:

That's a real bummer! :banghead:

Looks like Rock Auto has the best price for the 68043089AA replacement unit.
https://www.rockauto.com/en/parts/mopar ... ilter,6216

Funny you should mention that - it's same the one I ordered about 15 minutes before you posted it :SOMBRERO:

It's annoying, but I did figure that installing the in-tank pump would show up any weaknesses in the fuel system. Looks like that assumption was correct, which I'm OK with - better to have the failure now while it's fresh in my mind than to have it take place six months or a year down the road when I'm left wondering why something just bit the dust. Besides, this eliminates one more air leak (now turned fuel leak, which IMHO is worse) - and I'll have a fuel filter on hand for the next time it needs to be changed.

Contemplating seeing about tearing down the broken one once the new one is on. Have a hunch as to what may have happened, but confirmation would be nice.

GordnadoCRD · **Posted:** Fri Sep 20, 2019 5:27 pm

casm wrote:

WWDiesel wrote:

That's a real bummer! :banghead:

Looks like Rock Auto has the best price for the 68043089AA replacement unit.
https://www.rockauto.com/en/parts/mopar ... ilter,6216

Funny you should mention that - it's same the one I ordered about 15 minutes before you posted it :SOMBRERO:

It's annoying, but I did figure that installing the in-tank pump would show up any weaknesses in the fuel system. Looks like that assumption was correct, which I'm OK with - better to have the failure now while it's fresh in my mind than to have it take place six months or a year down the road when I'm left wondering why something just bit the dust. Besides, this eliminates one more air leak (now turned fuel leak, which IMHO is worse) - and I'll have a fuel filter on hand for the next time it needs to be changed.

Contemplating seeing about tearing down the broken one once the new one is on. Have a hunch as to what may have happened, but confirmation would be nice.

I would be interested in seeing the broken down parts laid out with the failure indicated.
I would be willing to bet many air in fuel issues people fight come from some issue with the fuel head.
I would reconsider which is worse though... An air into fuel leak that is nearly invisible to be found, and frustrating to the point that some just give up and sell it on, OR, a fuel leak which can be seen rather soon, and repaired; Job Done.

AS far as construction goes, there are rubber gaskets between the filter and the fuel heater unit, which is held to the primary base by a dual=threaded tube. When you remove the tube, it loosens the fuel heater and temp sensor "donut" from the base. This plastic donut is the source of many problems. Cracking is surprisingly common. There are also rubber gaskets between the heater donut and the primary base. The heater is 300watt. Its as much as makes no difference to the circulating fuel, but when in such close and pressurized proximity, it could cause that gasket to fail as well.

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

GordnadoCRD wrote:

I would be interested in seeing the broken down parts laid out with the failure indicated.

I'll see what I can do on that front, because I'd like to know what went South as well. It may be a while before I have the time to do it, though.

Quote:

I would be willing to bet many air in fuel issues people fight come from some issue with the fuel head.

Agreed. I'm just hoping that the problem doesn't repeat itself with the new one.

Quote:

I would reconsider which is worse though... An air into fuel leak that is nearly invisible to be found, and frustrating to the point that some just give up and sell it on, OR, a fuel leak which can be seen rather soon, and repaired; Job Done.

From that standpoint: yes, agreed.

Quote:

AS far as construction goes, there are rubber gaskets between the filter and the fuel heater unit, which is held to the primary base by a dual=threaded tube.

From what I've seen so far of units that have been taken apart, it's both conceptually (and functionally) similar to kits I've used in the past for remote-mounting oil filters on gas engines. Makes sense, because that's essentially what the fuel filter head is.

Quote:

When you remove the tube, it loosens the fuel heater and temp sensor "donut" from the base. This plastic donut is the source of many problems. Cracking is surprisingly common. There are also rubber gaskets between the heater donut and the primary base.

Thanks for the heads-up; I'll keep an eye out for that once I'm in there.

Quote:

The heater is 300watt. Its as much as makes no difference to the circulating fuel, but when in such close and pressurized proximity, it could cause that gasket to fail as well.

Makes sense, and yes, I can't see how the heater could do much good for fuel moving past it, either. About the only thing I can think of is that its main purpose is to heat the filter head (which I've burned my hand on the output side of before) in order to provide some resistance to gelling in cold temperatures. Even so, it doesn't seem like it would be terribly effective.

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

Filter head, filter, and water-in-fuel sensor are replaced. Decided to write off the 1000-mile filter that was in there given that there was a history of fuel contamination and just know that it was all done at once.

Noticeable improvement in running, which is unsurprising given the air (later fuel, after the in-tank pump installation) leak coming from the plunger on the old one. Going to hopefully tear the old one apart this weekend and try to figure out what failed behind the plunger; from looking at the new one, I think I have some ideas as to how to get to that side of things.

WWDiesel · **Posted:** Wed Sep 25, 2019 2:11 pm

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

WWDiesel wrote:

:POPCORN:

I'll keep you informed :SOMBRERO:

Diesel Dan · **Posted:** Fri Sep 27, 2019 8:59 am

Any thoughts about using a filter assembly for a Duramax?
Those are rebuildable and have excellent filters available.

WWDiesel · **Posted:** Fri Sep 27, 2019 11:08 am

Diesel Dan wrote:

Any thoughts about using a filter assembly for a Duramax?
Those are rebuildable and have excellent filters available.

If it has fuel heater and and fuel temperature sensors that are compatible with the Bosch system but GM uses Denso electronics on their Duramaxs.

There are other options, some have installed the larger Cummins filter head and some have installed the Racor filter head.
Both requires figuring out how to get the electrical components all connected and functioning properly.

See this:> http://liberty.eurekaboy.com/racor.htm

Fuel filter head leak fun

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