Jeff's Rear Poly EFI tank?

[Qumanchew]

I'm not in the market for one of these at the moment, but to the op, thanks for taking the time to write up an extensive review. This will help out a lot of people in the future. You did a great job of pointing out the short comings Without just bashing the product.

 

[EFI Guy]

It's a great write up indeed. I appreciate the details! It's pretty safe to say the body lift is a must unless you're willing to make modifications.

Did tightening the pump solve the seepage?

 

[Scott McKelvey]

It's a great write up indeed. I appreciate the details! It's pretty safe to say the body lift is a must unless you're willing to make modifications.

Did tightening the pump solve the seepage?

No. The stock F-150 tank for the 1999-2003 pump is steel. The Poly tank is like teflon: nothing sticks to it. Granted this noticeable to me b/c I haven't closed the trap door yet, but I can see and smell the gas weeping out (it is a weep, not a leak). I tried Copper Spray-a-Gasket, and it was better (I Think). I thought it might be overtightening, so i tried loosening things too.

Since I have the trap door, it's pretty convenient for experimenting. Next on the list is cutting my own cork gasket, and/or a nonhardening sealant that will stick to the poly tank (Yamabond, indian head........).

I'm not in the market for one of these at the moment, but to the op, thanks for taking the time to write up an extensive review. This will help out a lot of people in the future. You did a great job of pointing out the short comings Without just bashing the product.

No bashing whatsover. I've put ~150 miles on it and it's working great. It's a new product to market, and imagine accounting for all the variations and modifications that can occur over 50 years on these vehicles (impossible). The maker has been more than happy to talk. I'm just dealing w/ minutia honestly.

 

[ntsqd]

Hylomar?

 

[Scott McKelvey]

I got the fuel gauge adjuster installed today. I used velcro command strips (and the wires are loose enough) that I can pull it out for re-adjustments.

I still highly recommend that you test and adjust the unit (using test leads) while the pump is out of the tank, BEFORE installing the tank, otherwise I think you're shooting in the dark.

Finally wired in the fuel gauge adjuster.

1. Made a tool to remove the switch ( but I have a mill+lathe), but you're probably off better buying one. I plan on painting the dash, so i'll need it anyways. FYI, the orange wire is the feed from gauge, the yellow goes to the auxillary tank, and the pink (at least in the aftermarket wiring harness) goes to the rear tank
2. I actually omitted the switch from the wiring since I have one tank. The orange wire from the gauge goes directly to the module, and the module goes directly to the tank sending unit. So this is mounted w/ velcro command strips to the kick panel w/ enough slack pull it out and re-adjust the settings.
   1. 

The instructions aren't quite right either, so here they are with my notes. Here

 

[Scott McKelvey]

Hylomar?

Hylomar is basically yamabond. I come from the vintage harley world, and they seem equivalent. So I'll report back.

 

[ntsqd]

Not the yamabond and hylomar that I'm familiar with. Used to use yamabond on ACVW engine case halves and it very much lived up to the "bond" in it's name.

First used hylomar on a Hewland transaxle to stop it's o-ring sealed joints from leaking. The German made parts were fine, the English made parts had horrible surface finish in the o-ring gland surfaces. Very much doesn't bond to anything except for the clothing that you accidentally get it on.

Recently I was made aware that the hylomar product line has radically expanded, so what you're calling "hylomar" and what I'm calling "hylomar" are probably not the same product. The original hylomar product is a bright blue non-hardening polyurethane sealant.

 

[Scott McKelvey]

Not the yamabond and hylomar that I'm familiar with. Used to use yamabond on ACVW engine case halves and it very much lived up to the "bond" in it's name.

First used hylomar on a Hewland transaxle to stop it's o-ring sealed joints from leaking. The German made parts were fine, the English made parts had horrible surface finish in the o-ring gland surfaces. Very much doesn't bond to anything except for the clothing that you accidentally get it on.

No, I'm 100% w/ you. I typically build pre '65 harleys, so I know exactly what you're saying on the engine cases. Yamabond #5 is the sticky stuff. Yamabond #4 is the non-hardening. I guess it depends on whether you like "reds" or "blues".

 

[ntsqd]

See? I only knew of the sticky yamabond. Just can't keep up.......
LOL

 

[Speedrdr]

No, I'm 100% w/ you. I typically build pre '65 harleys, so I know exactly what you're saying on the engine cases. Yamabond #5 is the sticky stuff. Yamabond #4 is the non-hardening. I guess it depends on whether you like "reds" or "blues".

Is that what has been colloquially called “Gorilla Snot” by motorcycle mechanics?

 

[DirtDonk]

For me, the term “gorilla snot” was the sealant that was used to install windshields in applications that didn’t use the gasket/seal type of retention.
Came in coiled rope form.
Is that the same thing as “dumdum” and another nickname or two? I forget the actual product name, but we’ve discussed it around here a few times I believe.
Sticky stuff!

 

[DirtDonk]

Butyl was the other term I was looking for.
Butyl rope maybe? Or tape?

 

[ntsqd]

Gorilla snot is universal, can be applied to many different substances.

 

[Scott McKelvey]

OK, so here's my final conclusion on the fuel pump sealing (see post 61 for update):

1. The stock rubber gasket is simply not a good fit for the poly tank.
   1. All of the screw holes are outside of the seal.
   2. The mounting screws for the threaded lock ring are also outside of the stock seal (i touched on that in my video)
   3. it just doesn't seal well on the Poly, i don't think. But I could be wrong, and the fuel was always wicking up the mounting screws on the pump, but I don't think so.
2. Jeff Burton sent me an 1/8" cork gasket (free of charge) that he says they use on the tanks where people don't use the EFI pump.
   1. better idea in my opinion since it covers all the holes.
   2. And seemed to be better as far as sealing. 1/8" is just enough.
   3. I'm a fan Copper Spray-a-gasket, but that still wasn't enough.
   4. When the tank was FULL, i was still getting fuel weeping out: it seemed like it was primarily the bolt holes, but I couldn't tell
3. (RESOLVED) My final conclusions:

1. Don't bother w/ the OEM gasket. Either cut your own from 1/8" cork from a place like autozone, or contact Jeff Burton (the maker of the tank)
2. Use Hylomar blue or Permatex 85240 (equivalent) to coat everything: the gasket, the M6-1 mounting bolts, and 3 bolt heads for the mounting ring.

TO WRAP THINGS UP (updated 6/26/26 w/ latest info), I like this tank+pump alot for the reasons advertised:

1. Slightly smaller than the 23gal options, but doesn't hang as low, etc.
2. price savings compared to the 23gal options.
3. No rust to worry about on tank or skid plate.
4. the Stainless skid plate is nice and heavy duty.
5. Weight- it's light. so easy install and remove. And why not save a few pounds where you can.
6. Includes late model OEM fuel pump AND sending unit, which costs like $30 to replace from any auto parts store any day of the week.
7. I consider myself a beta tester of sorts (but that's only b/c I couldn't find alot of reviews or detail out there. for all I know there's a ton of these installed), and hopefully my details help other folks.
8. Unless you have a 1" body lift, it'll work, but plan on cutting a trap door in the floor (which I don't think is a bad thing, in fact I think it's a plus in the end), and possibly trimming those top blocks.
   1. If you go the trap door route, message me and I'll get you my measurements. Unfortunately I cut my hole a little too far forward, so it'll save you the mistake.
   2. If you have a 1" or more body lift, have at it!
9. As far as Fuel pumps, Jeff Burton says that the slightly earlier Ford Explorer fuel pump shares the same bolt pattern, and doesn't require a return line, for you guys w/ stock EFI systems. I was installing a Holley sniper so I was glad to have the return in the pump.
10. If you buy from Jeff's Bronco Graveyard, add the following to your list:
    1. Permatex 29132 ($13) for the gasket between the fuel pump and tank.
    2. six m6-1 bolts and washers (any hardware store or Ford part #F5AZ9N005B)
    3. Buy 1/8" Nitrile sheet of gasket material and cut your own between the pump and the tank.
    4. Buy a 3/8" quick connect plug (feed)
    5. Buy a 5/16" quick connect plug (return)

1. Here's the facebook link https://www.facebook.com/share/p/166NoKXpXD/. The email is there, but it's broncoatank@gmail.com
2. And here's the Jeff's Bronco Graveyard link. https://shop.broncograveyard.com/19...Gallon-Poly-Rear-Fuel-Tank/productinfo/10275/. Free Shipping is hard to beat. $799 or $999 w/ stainless skid plate.

 

[dao1980]

Thanks everyone for all of the good info on installation!
Just received my poly tank with skid-plate and pump/sending unit from Jeff's. Looking forward to having it all installed and running.
Probably going to do some prep work to clean up the wiring, fuel lines, etc. and should probable clean up and get a fresh coating the frame area while it is exposed.

 

[Scott McKelvey]

Thanks everyone for all of the good info on installation!
Just received my poly tank with skid-plate and pump/sending unit from Jeff's. Looking forward to having it all installed and running.
Probably going to do some prep work to clean up the wiring, fuel lines, etc. and should probable clean up and get a fresh coating the frame area while it is exposed.

Yes, that's why i said it can be a 2 hour job, or a 40hr job depending on how much you want to open pandora's box: cleanup while the tank is out, wiring, plumbing, etc.

I look forward to hearing how the actual tank install goes for your (pandora's box aside).

 

[jmhend]

I thought I was reading this throughly but does anyone have any measurements? I see on Jeff’s site is says the tank is 2 3/8 lower but I don’t have the reference.

https://shop.broncograveyard.com/mo...Gallon-Poly-Rear-Fuel-Tank/productinfo/10275/

More economical than 23-gallon tanks. This tank only hangs 2-3/8" lower than the original fuel tank so maximum ground clearance is still achieved. Larger tanks hang lower and hinder ground clearance.

 

[Scott McKelvey]

What

I thought I was reading this throughly but does anyone have any measurements? I see on Jeff’s site is says the tank is 2 3/8 lower but I don’t have the reference.

https://shop.broncograveyard.com/mo...Gallon-Poly-Rear-Fuel-Tank/productinfo/10275/

More economical than 23-gallon tanks. This tank only hangs 2-3/8" lower than the original fuel tank so maximum ground clearance is still achieved. Larger tanks hang lower and hinder ground clearance.

What measurement are you looking for exactly? they say it hangs 2-3/8" lower than stock. Nuff said.

I can say I now have over 2000 miles on the setup. No issues, other than if I top off the tank and park it (meaning fuel is high enough that it is in the filler hose), it does weep fuel out of the the top of the pump gasket (even after hylomar and the 1/8" cork gasket, but it is minimal. Not even enough to leave a stain on the ground, but I can smell it). And that's an easy enough situation to avoid.

Unfortunately, I can also say that the skid plate does it's job. I have been off-road, although very close, nothing has hit the skid plate. However, I was shuffling cars around one night and the bronco slipped into Reverse (or didn't make it all the way into Park), and rolled into another car. Tank and skid plate unscathed.

 

[jmhend]

What

What measurement are you looking for exactly? they say it hangs 2-3/8" lower than stock. Nuff said.

I can say I now have over 2000 miles on the setup. No issues, other than if I top off the tank and park it (meaning fuel is high enough that it is in the filler hose), it does weep fuel out of the the top of the pump gasket (even after hylomar and the 1/8" cork gasket, but it is minimal. Not even enough to leave a stain on the ground, but I can smell it). And that's an easy enough situation to avoid.

Unfortunately, I can also say that the skid plate does it's job. I have been off-road, although very close, nothing has hit the skid plate. However, I was shuffling cars around one night and the bronco slipped into Reverse (or didn't make it all the way into Park), and rolled into another car. Tank and skid plate unscathed.

Scott, I don’t have a reference of what the stock measurement is if I did I can add the 2 3/8” to that number. If you are so kind to roll on that ground that is appreciated.

If not that’s fine too.

 

[Speedrdr]

What

What measurement are you looking for exactly? they say it hangs 2-3/8" lower than stock. Nuff said.

I can say I now have over 2000 miles on the setup. No issues, other than if I top off the tank and park it (meaning fuel is high enough that it is in the filler hose), it does weep fuel out of the the top of the pump gasket (even after hylomar and the 1/8" cork gasket, but it is minimal. Not even enough to leave a stain on the ground, but I can smell it). And that's an easy enough situation to avoid.

Unfortunately, I can also say that the skid plate does it's job. I have been off-road, although very close, nothing has hit the skid plate. However, I was shuffling cars around one night and the bronco slipped into Reverse (or didn't make it all the way into Park), and rolled into another car. Tank and skid plate unscathed.

Oopsie!! Hope it wasn’t your spouse’s car that got hit!