Fuel Filter Goo

PbFlinger · April 5, 2005

Hello All,

Yesterday I was doing some 100k service stuff to my 01 2500HD 6.0, which included changing the fuel filter. I am a habitual filter cutter, and opened up the old filter up to inspect. I was surprised to find the filter media covered in some sort of black goo, smooth & uniform. It had pretty much filled the weave of the media. I could scrape it off with a small screwdriver. It feels like dried out grease, seems to be made up of very fine particles of something, like a very thick graphite lube. The stuff looks too small & uniform to be hose degradation, but I suppose it could be.

The pump/filter were replaced at about 30k under warranty at a GM dealer for previous owner. This would make about 70k on the pump & filter. Some guys will say this is way too long. Maybe so. It's so easy on this truck I'll probably do it more often from now on. However I've cut open a blue million fuel filters, and the vast majority have looked like the day they were installed. This includes a couple with 200k on them. Granted, most of this was on pre-fuel injection stuff.

I have found very few fuel filters that were fouled by anything other than junk from defects in the vehicle itself (hose breakdown, tank rust, etc.). This leads me to believe it's coming from my pump. I have had no real drivability problems, other than spells where the truck won't start until the second or third crank (no matter how long I'd crank it each time). The pump is dead silent; I can't hear it without a stethoscope. As an aside, the fuel gauge has acted up since I've had the truck (I got it with about 37k miles on it, 103k now). It won't read below 1/4 tank; works ok otherwise. I figured this might have been caused by something that went wrong with the pump change, but now I'm wondering if this black stuff may be getting circulated in the tank & messing up the level sensor somehow.

Anybody seen this before? Any ideas where this goo is coming from? Does anybody know if these fuel pumps have any carbon wear surfaces? (That's what it looks like).

Thanks for any input,

Flinger.

snoman · April 5, 2005

Hello All,

Yesterday I was doing some 100k service stuff to my 01 2500HD 6.0, which included changing the fuel filter. I am a habitual filter cutter, and opened up the old filter up to inspect. I was surprised to find the filter media covered in some sort of black goo, smooth & uniform. It had pretty much filled the weave of the media. I could scrape it off with a small screwdriver. It feels like dried out grease, seems to be made up of very fine particles of something, like a very thick graphite lube. The stuff looks too small & uniform to be hose degradation, but I suppose it could be.

The pump/filter were replaced at about 30k under warranty at a GM dealer for previous owner. This would make about 70k on the pump & filter. Some guys will say this is way too long. Maybe so. It's so easy on this truck I'll probably do it more often from now on. However I've cut open a blue million fuel filters, and the vast majority have looked like the day they were installed. This includes a couple with 200k on them. Granted, most of this was on pre-fuel injection stuff.

I have found very few fuel filters that were fouled by anything other than junk from defects in the vehicle itself (hose breakdown, tank rust, etc.). This leads me to believe it's coming from my pump. I have had no real drivability problems, other than spells where the truck won't start until the second or third crank (no matter how long I'd crank it each time). The pump is dead silent; I can't hear it without a stethoscope. As an aside, the fuel gauge has acted up since I've had the truck (I got it with about 37k miles on it, 103k now). It won't read below 1/4 tank; works ok otherwise. I figured this might have been caused by something that went wrong with the pump change, but now I'm wondering if this black stuff may be getting circulated in the tank & messing up the level sensor somehow.

Anybody seen this before? Any ideas where this goo is coming from? Does anybody know if these fuel pumps have any carbon wear surfaces? (That's what it looks like).

Thanks for any input,

Flinger.

<{POST_SNAPBACK}>

I think you have it correct with it being hose residue.

PbFlinger · April 5, 2005

Sorry, I merged the two topics, and now it won't let me delete this post....So everybody just imagine you're hearing intermission-elevator music while scrolling past this post.

~Wingnut

Haulin' 8.1 · April 5, 2005

First thing off my head I think of is the activated charcoal in the EVAP canister. It's too early for me to decide how possible it is but it seems likely since the canister absorbs fuel vapors from the tanks. Check it's connecting hoses for evidence of the stuff getting out.

Vernon

Indy · April 5, 2005

First thing off my head I think of is the activated charcoal in the EVAP canister. It's too early for me to decide how possible it is but it seems likely since the canister absorbs fuel vapors from the tanks. Check it's connecting hoses for evidence of the stuff getting out.

Vernon

<{POST_SNAPBACK}>

They should have replaced the fuel filter when they changed the pump. I had a similar problem last fall. My fuel pump was squeeling like a banshee. I had it replaced and I changed the fuel filter, it appeared quite clean. A week later, 2 fuel injectors plugged up. When I brought them in to be ultrasonically cleaned and tested, the technician banged them on the counter and a blob of super fine black metal fillings fell out. We both agreed that these fine particles had come from the fuel pump grinding itself to death. The filter on the pump would have picked them up if they had come from the tank. They were so fine that they had passed through the external fuel filter. Keep an eye out in case your truck starts to run rough or misfire. I had all 8 injectors cleaned and tested, it's a lot cheaper than replacing them.

Mighty HD · April 6, 2005

Thank's to GM they dont put fuel filters on anymore. Idiots.

I don't have one on my 04 HD..It's in the tank

snoman · April 6, 2005

Thank's to GM they dont put fuel filters on anymore. Idiots.

I don't have one on my 04 HD..It's in the tank

<{POST_SNAPBACK}>

Thats so you have to take it to the shop for servicing. (Nice to know that too)

Mighty HD · April 7, 2005

That's what they think. I'll do it @ home. I love having all the "speciality tools"

Mattt · April 8, 2005

If you wouldnt mind, how did you get that fuel filter open? I cant see using some sort of grinder to cut it open? What is the trick to opening it without starting a fire?

Also, how do you cut open an oil filter also? Im guessing there must be some trick for both of these. Thanks in advance

Hello All,

Yesterday I was doing some 100k service stuff to my 01 2500HD 6.0, which included changing the fuel filter. I am a habitual filter cutter, and opened up the old filter up to inspect. I was surprised to find the filter media covered in some sort of black goo, smooth & uniform. It had pretty much filled the weave of the media. I could scrape it off with a small screwdriver. It feels like dried out grease, seems to be made up of very fine particles of something, like a very thick graphite lube. The stuff looks too small & uniform to be hose degradation, but I suppose it could be.

The pump/filter were replaced at about 30k under warranty at a GM dealer for previous owner. This would make about 70k on the pump & filter. Some guys will say this is way too long. Maybe so. It's so easy on this truck I'll probably do it more often from now on. However I've cut open a blue million fuel filters, and the vast majority have looked like the day they were installed. This includes a couple with 200k on them. Granted, most of this was on pre-fuel injection stuff.

I have found very few fuel filters that were fouled by anything other than junk from defects in the vehicle itself (hose breakdown, tank rust, etc.). This leads me to believe it's coming from my pump. I have had no real drivability problems, other than spells where the truck won't start until the second or third crank (no matter how long I'd crank it each time). The pump is dead silent; I can't hear it without a stethoscope. As an aside, the fuel gauge has acted up since I've had the truck (I got it with about 37k miles on it, 103k now). It won't read below 1/4 tank; works ok otherwise. I figured this might have been caused by something that went wrong with the pump change, but now I'm wondering if this black stuff may be getting circulated in the tank & messing up the level sensor somehow.

Anybody seen this before? Any ideas where this goo is coming from? Does anybody know if these fuel pumps have any carbon wear surfaces? (That's what it looks like).

Thanks for any input,

Flinger.

<{POST_SNAPBACK}>

Wingnut · April 8, 2005

Put the air compressor hose in one end, and blow a metric ton of air through there...That should evaporate all the gas in it.

It's 4am...I'm just making stuff up now.

snoman · April 8, 2005

Put the air compressor hose in one end, and blow a metric ton of air through there...That should evaporate all the gas in it.

It's 4am...I'm just making stuff up now.

<{POST_SNAPBACK}>

Better yet you can do like I have done a few times repairing fuel tanks. I fill the tank with engine exhaust from a gas engine after I flush it out so it cannot support combustion anyway.

Mighty HD · April 8, 2005

You can use a large pipe cutter.

snoman · April 8, 2005

You can use a large pipe cutter.

<{POST_SNAPBACK}>

That would be the ticket with round fiters gas and oil alike!

PbFlinger · April 14, 2005

If you wouldnt mind, how did you get that fuel filter open? I cant see using some sort of grinder to cut it open? What is the trick to opening it without starting a fire?

Also, how do you cut open an oil filter also? Im guessing there must be some trick for both of these. Thanks in advance

Hi Mattt.

It takes about 15 seconds with the right tool.

I have a filter cutter that as the other fellow said works like a big pipe cutter (which will work if you have one, but cost more than a purpose made cutter). The purpose made cutters are a little more handy because they have a flat surface that the oil filter gasket can sit on while you turn the filter, keeps the cutter wheel aligned better. Once inside the can, I usually cut through the filter media pleats all the way around at both ends with a box knife, then cut it lengthwise to free it from the center support so I can stretch it out flat & have a good look. The fuel filter was a little different because of the nut sticking out on both ends of the can. I zoomed one of these off with a hacksaw, then cut it just like an oil filter. I could have drilled a big hole in my cutter so I could do similar filters in the future, and may still do so.

These cutters are available from numerous sources. Most big race car suppliers or aviation tool houses should carry them. Here's a couple of links:

http://store.summitracing.com/default.asp?...ch.asp&x=29&y=7

http://www.sportys.com/acb/showdetl.cfm?&d...product_id=5733

http://www.airwolf.com/Default.aspx?Pg=Pro...lter_Cutter.htm

http://www.aircraftspruce.com/menus/to/oilfiltertools.html

I am an airplane mechanic, and I got mine when I was working on light aircraft years ago. It is a requirement to cut the filters on A/C engines, to make sure there isn't anything "making metal" in the engine. Sometimes you can see problems developing before they get real expensive (some light plane engines are in the $50,000+ each, rebuilt, category). Crashes due to engine failure get kind of spendy too.

I have worked on airliners for a long time now, and they are a little different. Most big turbine filters come apart so you can see the element, and they have chip detectors in most of the fluid systems so filter inspection isn't as important anyway.

I still do it on all of my car & bike filters just out of habit.

I have a $200+ Champion cutter, and the Tavia model. The Tavia works just fine, but is not made near as well as the Champion. I doubt if the average guy would want to spend $200 on something like this, though, unless you are using it all of the time as I used to.

Hope this helps!