Prado 120 sub tank in a GX470 - has anyone done it? Well I’m gonna try!
- Thread starter Toyoland66
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Very nice write up, thanks for posting all the pictures.
@Toyoland66 so now that you have had some more time with everything done any issues?
Also now that you have done it once ... what do you think a time est. would be to do it again knowing what you know and all?
Also now that you have done it once ... what do you think a time est. would be to do it again knowing what you know and all?
- Thread starter
- #124
Good question. I am still working through a couple details with the evap system relocation and I’m not happy with the filler hose issue so I’m trying to figure out how to adapt the prado filler hose to the GX tank. That said everything is functioning as it should. No check engine lights, no issues filling (aside from the cost).
There is only so much prep you can do ahead of time; building the sub tank with its components, removing the spare tire crossmember, and the subtank rear mounts. The new fuel pump, hanging the subtank, and installing the new filler need to all be done at the same time. It is easily done in a day if you have no issues. In summary assume 2 days of prep work that can be spread along as many days as you want, and 1.5 days to install and cut over.
I hope to have all the little details buttoned up over the new year weekend.
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so in other words... order parts... prep them... arrive on saturday morning early at your place get a hotel room nearby and leave sunday afternoon... got it!
- Thread starter
- #126
I have been negligent about updating my latest progress. I got the charcoal canister permanently mounted which required remote mounting the vacuum pump/ vent valve portion.
the pump seals to the charcoal canister with a slip/ o-ring fitting, the pump being the male side and the canister being the female. So the new fitting is a 1.5” I.d. Tube cap with a 3/4“ hose barb welded to it.
I ordered the tube cap from McMaster and it was pretty thin metal, so when I welded the heavy hose barb to it I had a few burn through. So in order to ensure it was airtight I poured some epoxy into it.
The charcoal canister is a bit easier, just a flat piece of 1/8“ plate with a 90deg 3/4 hose barb welded to it. I welded it from the underside and then ground it smooth.
Here are the two completed fittings
The plate seals to the charcoal canister with a gasket and sealant for good measure
the pump seals to the charcoal canister with a slip/ o-ring fitting, the pump being the male side and the canister being the female. So the new fitting is a 1.5” I.d. Tube cap with a 3/4“ hose barb welded to it.
I ordered the tube cap from McMaster and it was pretty thin metal, so when I welded the heavy hose barb to it I had a few burn through. So in order to ensure it was airtight I poured some epoxy into it.
The charcoal canister is a bit easier, just a flat piece of 1/8“ plate with a 90deg 3/4 hose barb welded to it. I welded it from the underside and then ground it smooth.
Here are the two completed fittings
The plate seals to the charcoal canister with a gasket and sealant for good measure
- Thread starter
- #127
Unfortunately I had to drop the subtank to get the charcoal canister into its final position above the frame rail. Reminder that this is where the air compressor lives if you still have the air suspension so this won’t work if you haven’t converted to coils.
very hard to photograph but the front of the canister mounts with a piece of aluminum angle bolted through the floor with a nut welded on the interior side of the floor.
the rear mounts with a piece of steel angle that’s bolted to the rear of the canister, and that bolts to a piece of angle that is welded to the body.
There is very little room so not a lot of options.
very hard to photograph but the front of the canister mounts with a piece of aluminum angle bolted through the floor with a nut welded on the interior side of the floor.
the rear mounts with a piece of steel angle that’s bolted to the rear of the canister, and that bolts to a piece of angle that is welded to the body.
There is very little room so not a lot of options.
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- Thread starter
- #128
The rest of the components are mounted behind the subtank
not the most elegant with all the zip ties but it will do for now
not the most elegant with all the zip ties but it will do for now
- Thread starter
- #129
I didn’t get good photos of it but I ran the vent up by the filler terminated at a marine gas tank vent, the barb on the vent is 5/8 so I used a 3/4 to 5/8 adapter and ran 5/8 hose
I also extended the rear axle breather to the same spot while I was at it
I also extended the rear axle breather to the same spot while I was at it
Man I still have air, which is even more desirable with the extra weight.
Heat gun and remold the tank? Lol.
Heat gun and remold the tank? Lol.
I did a hunting trip and now I'm back looking at this again. Simply not enough fuel to drive a lot, and carrying jerry cans sucks. But I also think this might hang down too much for the kind of 4x4ing I run into around here, a lot of cross ditches and such where I'm dragging the rear end a little.
Has anyone looked at this tank as a possible fit?
fueltankparts.com
73-79 Ford F100 23 Gallon EFI Tank with Provision for OEM MU2101 Pump
SEE BANNER FOR CURRENT LEAD TIMES Tank Material: 1/8” 5052-H32 AluminumTank Dimensions: 31.5” x 24” x 10” Taper to 6”Approx Gallons: 23Fuel Fill: 2.25” Ribbed for HoseVent 1: 5/8” Ribbed for Hose Fill VentVent 2: ½” NPT Tank VentFuel Feed: Provision for OEM AC Delco MU2101 Pump (pump not...
fueltankparts.com
I can’t see any advantage in messing with a random tank over just buying the long range America kit. By the time you make some random tank work it will cost the same and have consumed a lot of your time.
Do you have a total cost on this? I run the first LRA for GX470s in the 33 gal and armored it up. Wife has the 24. Interested in a price compare.
- Thread starter
- #135
@GXO I just went back and totalled up orders, I have a spreadsheet but didnt do a great job of tracking how much shipping etc ended up. All the items were ordered from UAE or Japan so shipping was a significant part of the overall cost. It was just over $1,500 in OEM parts plus some misc hoses and fittings etc from the local parts store or McMaster, so probably somewhere around $1,800 total.
I am having a recurring issue with fuel getting pumped into the charcoal canister, It seems to happen if I get stuck in stop and go traffic for an extended period of time. To fix it I am going to start by running the evap plumbing in series so only the sub tank vents to the charcoal canister and see if that resolves it. I think that is how @grinchy plumbed his although his canister is in the engine compartment.
I am having a recurring issue with fuel getting pumped into the charcoal canister, It seems to happen if I get stuck in stop and go traffic for an extended period of time. To fix it I am going to start by running the evap plumbing in series so only the sub tank vents to the charcoal canister and see if that resolves it. I think that is how @grinchy plumbed his although his canister is in the engine compartment.
Not horrible, but you also had the R&D burden of being one of the first if not the first! I know the LRA tanks do suck into the charcoal canisters until the plumbing was changed to your thoughts above. The nature of the transfer resulted in wicking and side flow.
I can confirm that the lx570 evap chain is main -> sub -> canister. If it’s proving an issue also could consider looping the evap line higher than the filler.
I ran my evap canister line all the way to the engine compartment, so length on this line appears not to be an issue.
I ran my evap canister line all the way to the engine compartment, so length on this line appears not to be an issue.
- Thread starter
- #138
I ran a high loop last time I had this issue thinking it would force fuel to balance through the filler if it got that high. That worked until earlier this week when I got stuck in traffic. I can’t explain how fuel still got pumped into the charcoal canister but it did. Perhaps with both tanks vents merging to go to the charcoal canister, once fuel made its way to the tee the sub tank could no longer vent to allow fuel to drain into it from the main tank. I think we are all aware that the evap system on these vehicles is problematic even in stock configuration.
As part of replumbing this one of my goals is to get rid of any sags in the vent so fuel has a way to drain back into the tank in the event that it gets burped into the line.
- Thread starter
- #139
I am a bit late with this update but I re-plumbed the evap several weeks ago to run in series and vent from the sub tank. So far it appears this is the way I should have done it to begin with. With the old setup I was still getting some gas smells in the garage which tells me that fuel was getting into the charcoal canister and a couple times it filled the canister to the point that fuel was leaking out of the vent up by the fuel filler.
Old setup with main and subtank vents teed and into canister. The filler vent from the main tank was tied to the return on the sub tank.
New plumbing with main tank vent and filler vent both tying into subtank return. I used a NPT fuel tee with thread in hose barbs which cleaned up the plumbing quite a bit.
I ran the evap vent from the sub tank the long way around the subtank trying to emulate the 3 sides and down routing that a rock crawler uses for fuel tank venting which is supposed to prevent leaking from off camber or roll over.
Old setup with main and subtank vents teed and into canister. The filler vent from the main tank was tied to the return on the sub tank.
New plumbing with main tank vent and filler vent both tying into subtank return. I used a NPT fuel tee with thread in hose barbs which cleaned up the plumbing quite a bit.
I ran the evap vent from the sub tank the long way around the subtank trying to emulate the 3 sides and down routing that a rock crawler uses for fuel tank venting which is supposed to prevent leaking from off camber or roll over.
