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Does any body know why they don`t recommend filling the fuel filter first before installing them. Have changed my fuel filter twice now with no problems. Read somewhere that`s a no-no. can anyone explain. Oh I`am new to this forum, seems like alot of info here. Thanks Bartster Ps I have a LLY
 

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I'm guessing you just read this on the other thread. Like I said, I've always done it & I've never had any problems. It's doing the same thing the hand primer is doing just with out the finger aches.
 

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SoCalMike is correct you are introducing unfiltered fuel into your injection system and all it takes is one little piece of ferrous metal or crap to screw up an injector that costs 400.00 and a lot of work to replace or another 4-500 dollars at the dealer. So the question is.................is it really worth the extra time you save to not pump the primer pump on the fuel filter head.

Its all up to you the truck owner as to what you want to do. I personally put the filter on dry and pump it up with the primer button. :thumb
 

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Do not pre-fill filters. as stated it introduces un-filtered fuel to the injectors.

The particles that will damage your injectors are measured on a micron level, you won't be able to see them.
 

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I was not aware it would still be unfiltered. Thanks guys. Consider me schooled.
 

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I was not aware it would still be unfiltered. Thanks guys. Consider me schooled.
Depends where it goes in, but yes. You are introducing unfiltered fuel. Buy a lift pump and it'll prime for you.
 

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I was not aware it would still be unfiltered. Thanks guys. Consider me schooled.
Filters work outside in. Meaning that the fluid is introduced to the filter through the outside of the filter housing then is pushed through the filter media. Once the fluid is in the center of the filter it is filtered fluid and is sent out through the center of the filter and down the oil path for that particular engine or trans or what ever it is. Thus when you prefill any filter through the middle of the filter you have introduced unfiltered fluid to that system. :drink
 

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Ill prefill oil filters because I think that the effects of 5-10 seconds of no oil is far worse than the minute possibility of me putting anything large enough through the oil system to cause damage, On a fuel system I rather just spend a few more minutes pumping the primer than worry about killing 4k worth of injectors
 

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Discussion Starter #13
Thanks all for the info you have given. Learn something new every day. My Father always told me. When your thru learning, Your THRU. Bartster:drink
 

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Ill prefill oil filters because I think that the effects of 5-10 seconds of no oil is far worse than the minute possibility of me putting anything large enough through the oil system to cause damage, On a fuel system I rather just spend a few more minutes pumping the primer than worry about killing 4k worth of injectors
I do not prefill any filter at all. You have to remember that when doing an oil change generally we all do it hot which means you just ran the truck and there is oil in the passages & journals. If your oil is good you will not have a dry run situation at all. The oil in the passgaes and journals will lubricate for 3 seconds until the oil filter fills and and sends oil on through the engine. I doubt its 10 seconds that the engine runs without oil to fill an oil filter. I understand your logic but I don't think you have much to worry about. 1 piece of anything that dropped into the filter could damage your 16k engine. In my mind its not worth the chance to introduce unfiltered fluids into a system.
 

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Don't you also have to prime to ensure there is no air in the lines too?
The fuel filter yes that is why the primer button is on top of the fuel filter head. The oil and spin-on trans filters no they have pumps that pump the oil and will push the air out.
 
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