Pookster
1/2 ton status
Do the diesel's in our trucks have an in tank sock filter? We dont have a fuel pump in tank so it would seem kinda silly to have one, but I have heard conflicting information, with no real answer....
CK5
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Diesel Fuel... sock?
- Thread starter Pookster
- Start date
Iron_Weasel
Registered Member
I checked a diesel Blazer manual at random, so I got info off an 85 since you didn't specify a year. Anyway, from the digrams and information, there is no in tank filter...just the normal fuel filter/water seperator.
Pookster
1/2 ton status
thanks dude. 
At least in the gas applications, it doesn't matter if theres an in-tank pump or not. There are two functions of the sock: prevent crud from reaching the fuel pump (electric or not) and to prevent water from getting to the engine.
Perhaps diesel can get too "thick" to get through a sock filter, and with a water seperator already, no reason for that in the tank.
Perhaps diesel can get too "thick" to get through a sock filter, and with a water seperator already, no reason for that in the tank.
Diesel Dan
1/2 ton status
One of the main reasons for the "sock" is for fuel pickup. It acts like a candle wic. Only one spot of the sock needs to be in fuel and it will draw in fuel. That's how they can basically suck the tank dry when if all it had was an open end pipe it would leave quite a bit of fuel in the tank.
And yes, it should have one. It is not called a filter, IIRC GM calls it a strainer.
And yes, it should have one. It is not called a filter, IIRC GM calls it a strainer.
Pookster
1/2 ton status
crapola. Ok, so, any ideas as to how often this sock needs to be replaced? Seems kinda pointless in a diesel application, as that "wicking" action would sitll introduce air into the system and cause the engine to stall. Not to mention all the usual crud that gets into diesel fuel that it needs good filtration.
I'd say that sock needs replaced about once every 15-20 years.
*IF* they are bad it seems that its because they have rubbed the bottom of the tank too long, and get a hole worn in them. Also, if the tank is in poor condition, the sock can get plugged up with crud, which in some extreme cases hurts performance.
The Delco electric fuel pumps that I bought all came with a sock, so GM seems to think that fuel pump replacement is about the interval the sock should be replaced. Since the fuel pumps seem to typically last 100,000 miles+, that's a pretty big interval.
*IF* they are bad it seems that its because they have rubbed the bottom of the tank too long, and get a hole worn in them. Also, if the tank is in poor condition, the sock can get plugged up with crud, which in some extreme cases hurts performance.
The Delco electric fuel pumps that I bought all came with a sock, so GM seems to think that fuel pump replacement is about the interval the sock should be replaced. Since the fuel pumps seem to typically last 100,000 miles+, that's a pretty big interval.
