I am doing the pre pump mod this evening and have some questions before i get started. (I also did searches on this topic but still need a little clarification, sorry!)

The supply fuel line coming off the top of the tank running to the pump goes rubber then steel then rubber to the pump. When doing this mod am i incorporating the steel fuel line on the frame rail , or doing away with it altoghether as i run my new 10' of fuel line.

Do i need to drop the tank a little to run my new 3/8" fuel line off the top of the tank? Or is it accessible without dropping it? Ive seen plenty of pics and tips on doing the hutch/harppon mod incorporated with the pre pump mod but never just an editorial on doing the pre-pump from the tank to the pump.

Tools i have are the quick disconnect tool for the fuel line on top of the tank. My new 10' 3/8 fuel line and 4 worm clamps. (2 on each end) Do I need anything else?

 

You can use the existing steel line. That's what I did.
I can't answer your question about dropping the tank.
Have you rolled under there just to take a look at all?

 

hey kwikk

Yeah, I cant see or get to the qd that is after the qd on top of the tank, going to the pump.

I can see the on on top of the tank and at the pump is what im trying to say. but from what i understand there is a third on the rail in between.

should i just do the one at the pump. I bought ten feet of fuel line becuase guzzle said he ran new 3/8 from the tank to the pump

 

That's the hold up on my pre-pump mod. If I'm going to drop the tank, I figure I might as well solve the in tank problems too. Gotta get all the items together. For an idea look here and you can see where the lines are in the pictures that follow the writeup. Hope this helps.

 

With all of the stuff I now have hanging off of the frame, there is no way I could use the existing steel line. I just capped it off for who-knows-why reasons..... Without doing the in-tank mods in conjuntion with the pump, you may be defeating some of the reasons for the pump mod. The internal mixer and emergency fuel pickup will most likely pickup some air when your tank gets low and I would suggest that you do as Tenn01 and wait until you can do both. The tank is really not that big of a deal to drop if it is very low on fuel.
If you do decide to go ahead and put the pump on now, I know that there was no way I could have reached the pickup line on the top of the tank without lowering it a few inches to get my arm up in there.
Other than the quick disconnects, you shouldn't need anything other than the regular hand tools and some electrical cutters/crimpers for the 12 volt power line.

If your'e interested, I just posted my pump mod HERE.

 

kwikk, guzzle, tenn

Thanks for the replys, i now understand that i can use the factory hard line and just get rid of the qd's inbetween. Do you think there are any advantages with going with the new line from end to end or is the the steel line 3/8' all the way.

Guzzle, i never run my tank below 1/4, except for right now so i am going to take the cheap aproach and do the pre-pump. other than the mixing bowl drawing air when im 1/4 or below i shouldnt have any air problems , right?

Im going to have a tranny jack and a reg. jack for both ends to lower the tank slightly. I will see how low you need to get the tank for doing just this portion of the mod and post back for others who are going the route i am.

also, after reading tenn's posting of diesel manors inst. on the mod it looks like i will have to cut the qd at the rail , becuase i have a 99.5 I have a cut off wheel, but have never cut a qd before , any tips?

 

Where did you purchase your fuel hose? I am having trouble finding a suppler.. Did you get the recommended 30R9 grade hose? One note.. i think your existing steel line is 5/16" (outside diameter) and your 3/8" hose (inside diameter) is going to be a loose fit if you end up using your steel line..I am watching all these posts about the fuel line mod's and i am going to do it also but like you i still have some questions.. I do feel you should go ahead and drop the tank and do the inside mod's. From what people are saying, that is more important than the line mod. My 2 cents worth..

 

due to the fact the steel line is 5/16" I just took mine completly out of the truck and tossed it and put the 3/8" hose from the tank to the pump, I like this better for 2 reasons, the first one is already noted it's smaller diameter and the second one is it eliminates 2 possible leaks that you would have if you put hose from the tank to the steel line than from the steel line to the pump.

 

i am running this 10 ft. of hose have it connected to the tank ,

know for my next question where do i run the hose? up the frame rail or over the tank?
i am running it from the tank to the pump

 

I basically just followed the same route that the original hose followed, and wire tired it to the wiring harness that goes along the frame rail.

 

Remember, this is a lower pressure or draw/suction hose so you will not need a 30R9 spec hose in front of the pump. Just make sure it's non-collapse hose rated for suction. And diesel fuel obviously.

 

hey guys,

well gott everything routed up through the frame and completed!

things i did differently:

1)I only loosened up the front tank strap completely and the back one a little. this allowed me to get my hands up on top of the tank to get my qd tool in there and still have enough room to tighten my worm clmps up with a 1/4" ratchet. saved a lot of time by not having to drop the tank.

2) with the tank being loose on the front all i had to do to route the new 3/8" line up the rail was push the tank to the side and shove the line up in the frame rail. the tricky part was getting the new fuel line to lay in on the rail where the tank wouldnt pinch it against existing lines. ( just had to push it up high enough to clear) After alot of checking and rechecking and rechecking as i was tightening the tank up i made sure nothing was pinching the new rubber line.

3) finished up connecing to the pump. zip tied everything and cycled the key 4 times checked for leaks. And started her up. Now i dont know if im exaturating but even with an 1/8 tank i had no more cackle. she purred like a kitten with no wiers injector noises. Mybe i had more of an air leak in the qd's than i thought. I know that with doing only this portion of the mod i will still be getting air in the mixing bowl especially with that litttle fuel in there, but man what a difference in engine noise. .

4) things i should have done i thought were a little iffy in my truck were pull the pump off and tap it to get any debris out. But my truck is a northeast truck with some salt wear and tear and if i busted one off those terminals i would have been sol.

All in all it feels like i have my pedal back, if that makes sense as it is more touchy to throttle response. It feels like it is working a whole lot less to achieve the speed/perfonrmance i would have gotten before.

sooo.. i ahave to say by far since i havent added a chip yet this is by far the best seat of the pants mod i have done yet.

 

oh and by the way i used 30R6 diesel rated line. from napa.

 

That sounds great. Now I'm really champing at the bit. Thanks a lot.

 

I have been following this for awhile and is very interseting reading. About a month ago I did just the prepump mod and not the in tank mods because of time(not having enough, LOL) and at the time I put a clear inline fitler before the pump mainly to use as a sight glass. I drove it for about 100 miles after filling the tank and still had air bubbles coming through the filter. The engine did run quieter so I must have been getting a tremedous amout of air before removing the QC's. I then went on a trip of about 600 miles and was noticing less rattle at times from the engine. At about 250 miles I climbed under and looked at the filter-sight glass and it was running clear fuel. Now if I keep the fuel tank over 1/4 tank the engine is smooth as silk and running between 1500-1700 rpm I can barely hear it running. I plan on doing the intank mods when the weather is better to eliminate any air at less than 1/4 tank. I guess the point of what I am trying to say is the prepump mod makes a tremendous difference in the way the motor runs and preforms if that is all someone has time for as a first, inexpensive mod that will yield some good results.