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Gas tank baffle repair

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BadDog, Nov 2, 2001.

  1. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Ok, I have been futzing around with the fuel system on this TBI conversion for too long. I've been looking for an outside the rail, small (short) TBI tank for some time. Why you ask? Why not run an inline 15psi TBI pump? I want an original TBI tank with the pump in the tank for 2 reasons. One, the in tank pumps are much cheaper. I can put a new one in and carry an extra (which I *will* do) for less than a decent external pump. And, two, they have baffled tanks and you don't (generally) have to worry about burning them up by running them dry. I've also heard they last longer due to the cooling from being in the tank. Only down side is the access problems but that won't be an issue with what I have planned.

    Anyway, I found/bought the first one about 3 months ago. Short bed (small) TBI tank, typical long bed tank (larger) is too long after cutting the frame down for shorter wheel base. Small dent on one end but looked good. Not smart enough to look inside before I got back. [​IMG] Got home and not only is the baffle broken loose (they are plastic) but it is FULL of rust. Looked good outside but in a hard wreck the force of the gas rushing forward will (apparently) tear these things off. So, call the yard, says he has another and will swap, so I go back a week or so later. This one is absolutely pristine, looks brand new and no dents at all. Plastic skid even has no marks (like I would use a plastic skid). It was already out (first warning) and I was in a hurry so I just swapped and ran. Too stupid to learn from my first mistake, but, in my defense, it looked perfect. Couple days later get around to checking it out and find that the baffle has a small hole in the bottom, just big enough that it would not work on sustained extreme angles. Call back again, he has no others. Says, "check back in a week or two". Months have passed and still no tank...

    So, now to my question ("FINALLY!", you say!).

    Does anyone know of a way to fix a small hole in those plastic baffles? Other than a hole (smaller than the size of a dime) this tank is perfect. Suggestions?

    The tank also has allot of dirt in it (setting open at the yard I think) but no rust at all. Any suggestions on the best way to clean it out? Never tried cleaning out a tank like this before. In the past, if I got a tank full of gunk, it was always on a carb engine. There I just put a cheap pre-filter in line and checked/changed/flushed it frequently. Can't do that (realistically) with a FI pump. I'm thinking just get some gas in a can, slosh it around, and pour it out the top port. Maybe filter it through a cloth and repeat. Then I just gotta figure out how to ditch the trashy gas...

    Russ

    85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked
    Some day: 4" lift, 44" tires, massive cutting, shorter wb and rear overhang.
     
  2. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Can it be that nobody has ever had to deal with a cracked baffle? I've never really fooled around with FI on a 4WD before, am I making too big a deal out of the baffle? As I understand it, if the pump sucks air, pressure is gone, so engine dies. Period. Carbs can keep going for a short time on the contents of the bowl, but not FI. So, as I understand it, without a baffle, extreme angles can only be attacked with between 1/4 and 1/2 tank. Also, I've been told that the pumps can be damaged if you let it run dry. Maybe I'm making a mountain out of a mole hill?

    If not, just a suggestion for an epoxy that would both hold to the plastic baffle (permanently) and not dissolve/cause problems permanently submerged in gasoline would be great. Obviously, any repair would need to be carried out through the pickup port.

    I don't want to put too much trouble into this tank. Eventually, I want to put the tank into a more safe location than on the side. But that will have to wait until I get around to cutting down the body/frame. For now, I just want to get it going so I can use it...


    Russ

    85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked
    Some day: 4" lift, 44" tires, massive cutting, shorter wb and rear overhang.
     
  3. Twiz

    Twiz 1/2 ton status

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    Could be because noone has ever delt with a plasic baffle before, or the gas thing too..

    I *think* liquid weld (that two part epoxy stuff, red and black packaging, can't remember the porper name for it. Too lazy to go check.) is fuel proof and if you overlap it on both sides of the hole, it shouldn't chip off. Stock fuel pump pick-ups have a screen built in on the pick-ups so that if it does chip, it should be caught in the screen.

    Is the hole stock? Maybe it has a reson for being there.

    Still, I think I'd run a "in-line" fuel pump..just because it would be easier to replace, unless you plan on making a hole in the bed of the truck to get the pick-up/pump out..

    I don't know, just hate to see ya' repling to youself..Good luck with it.

    <font color=blue>Twiz</font color=blue>
     
  4. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Hehe, thanks for the reply. I thought about JB Weld but it can only be put on one side. The hole is in the bottom of the baffle so I can't get the other side. It is definitely not supposed to be there, it is a very localized crack with a little piece missing. Looks like where the baffle attaches to the bottom of the tank. With the location of the hole, the baffle is useless. Probably broke it loose when all the gas rushed forward (looks like the truck it came out of hit something hard). Well, thanks for the reply. I'm looking at other options now but I may give the ol' JB a try...

    Russ

    85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked
    Some day: 4" lift, 44" tires, massive cutting, shorter wb and rear overhang.
     
  5. Twiz

    Twiz 1/2 ton status

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    JB weld- thats the stuff.. ya kinda have a unusual question here, wish I had something better..but I don't. sorry

    <font color=blue>Twiz</font color=blue>
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    The plastic used in the tanks *looks* like the stuff they use to make RV water tanks out of. You can buy "plastic welding" stuff for them. Caution here of course, gasoline vapors are extremely dangerous..but it may very well be exactly what you need.

    As to cleaning it out, I believe small amounts of gas dumped in, (gallon or so) sloshed around a bit, then turn the tank upside down, will get lots of crap to the center sump when you flip it rightside up. The baffles AFAIK, do not extend to the top of the tank, so the fuel/crud will "fall" to the top of the tank, fuel will pour out the sending unit hole, taking crud with it. Then when flipped rightside up, lots of the junk ends up in the sump like i said, and if you have small enough hands (or a nice helper) you can reach in with clean rag and scrape up the remaining particles. Repeat a few times, and let the in tank sock and external fuel filter do the rest I guess.

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     
  7. kpanza

    kpanza 1/2 ton status

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    Last time I replaced the fuel pump in my 87 with TBI, the baffle had broken off and was up against the side of the tank, just kinda bouncing around. I knew something was wrong when the truck would die when cornering. The hole where it mounts to the tank had cracked a little, so the bolt was no longer holding it down. Simple fix for me - just used a very large fender washer to cover more surface area of the plastic, it works like a champ now!

    Don't know if that is what you are looking for here, but that is what I did when mine cracked and came loose...
     

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