Factory sub tank - sourcing and fitment discussion

[grinchy]

Had an hour, made the sender cable extension.
For some reason the stock cable has four wires on it, pink, green, and two white/black stripes. Only two on the sender end (pink, green). I just terminated the extras.
Dug around and found 25 ft of wall rated OF speaker cable in 14 gauge. That’ll work.

 

[grinchy]

What about putting the canister on the engine back by the firewall?

that cardboard box is the canister mock-up . . .

lots of bolts available to adapt brackets on to

Concerns with this possible approach?

 

[grinchy]

It does not fit. front edge prevents hood from closing. Back to the power steering reservoir area.

 

[grinchy]

Relocated the drl resistor. This bolt hole was already here. I did drill a 5/16 or 8mm hole to put the little tab in. That was faster and easier than adding a rivnut. If it shakes loose i can always rivnut then, but I doubt it’s going anywhere. Bend the metal tab the connector is on up a few degrees to clear the fender.

 

[grinchy]

Move the power steering pump. Make sure to test for flex/stretch and keep the hose out of the belt line. Also need to put abrasion cover on the clip in the engine area that is now next to the return.
Two new rivnuts and a sheet metal screw where the fender is too thick for a rivnut up by the air box.

 

[grinchy]

New home for the charcoal canister. Also some bracket closeups. Nothing too stunning. Just bending scraps to fit. Had to make three brackets to fix the clearances and make it solid.
Rubs on the powers steering can holder, I think I’ll trim it.
Cut out most of the corner on the upper air filter plastic near bolt.

 

[Julian73]

New home for the charcoal canister. Also some bracket closeups. Nothing too stunning. Just bending scraps to fit. Had to make three brackets to fix the clearances and make it solid.
Rubs on the powers steering can holder, I think I’ll trim it.
Cut out most of the corner on the upper air filter plastic near bolt.

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[Julian73]

I would suggest drilling a stress relieve hole at the end of the saw cut

 

[grinchy]

Wired up the extension on the rear plug (10 pin that serves the charcoal canister). There were 7 wires in the bundle. Two are identical blue. If you're cutting this harness, try to track which blue is which (have marker or tape handy). I suggest uncovering the wires before cutting to make sure. I made an educated guess; we'll see when I plug it in if it was correct. This wire and 5/8" hose are now routed up front, but I don't have the evap plumbed yet, and don't have the pigtail soldered on in the engine bay either.

Also put the tank straps up and dry fit the tank again. I had to put in another rivnut for the left side strap. The tank strap points / indentations are straight, but this strap wants to go at an angle toward the center. It even has a tab on it to make sure you put the bracket in at an angle. I'm guessing revisions . . . not a huge deal. Took all of five min to put in a new rivnut. Had to eyeball position while holding up the tank and wasn't able to mark; I may have to put in a fourth if I didn't get it right. While on this strap topic the bolt clearance is tight on both, but near impossible on the left. Luckily I had a ratcheting stubby in 14mm. The swing I could get was only 2 clicks - about an inch of arc. Not enough for the an open end to see a new face. No clearance for my 1/2" sockets, may a 14mm short 1/4" would fit.

The next item to work through will be the filler. I'm excited to get out of fab land and into the 'factory fit' portion of the install for a bit.

 

[linuxgod]

Wired up the extension on the rear plug (10 pin that serves the charcoal canister). There were 7 wires in the bundle. Two are identical blue. If you're cutting this harness, try to track which blue is which (have marker or tape handy). I suggest uncovering the wires before cutting to make sure. I made an educated guess; we'll see when I plug it in if it was correct. This wire and 5/8" hose are now routed up front, but I don't have the evap plumbed yet, and don't have the pigtail soldered on in the engine bay either.

continuity test with a multimeter?

 

[002cl]

Hi All, new to the forum. Recently purchased a 2017 TLC. First project was removing the rear screens (with help from this forum). Next project will hopefully be the addition of this sub tank! Thanks to grinchy for sharing.

 

[grinchy]

continuity test with a multimeter?

Sure. I guess now that the wire is up front I can get it close enough to the driver kick panel to do some troubleshooting at the junction connector AK1.
Pin 14 or 15.

 

[grinchy]

Hi All, new to the forum. Recently purchased a 2017 TLC. First project was removing the rear screens (with help from this forum). Next project will hopefully be the addition of this sub tank! Thanks to grinchy for sharing.

for sure. i hope a pretty good idea of what it takes to succeed comes out of this install.

 

[grinchy]

Got the rear right tire off today. Tomorrow I hope to remove the fender splash shield.

Haven’t been able to find any guide on the rubber surround for the fuel door/ filler. Guess I’ll wing that.

 

[Toyoland66]

I just read the entire thread, its funny that I came across this today as I have been investigating in parallel what it will take to install a factory Pardo 120 sub tank into my GX470. From what I can tell the two vehicles have very similar sub tank systems.

-The Prado fuel gauge has a green fuel light and reads full to half full on the sub tank sender, then the green light lights up and the gauge jumps back to full and reads the main tank sender. I assume you would have to buy the entire cluster to get just the fuel gauge but if you had both clusters you could probably swap it in - who knows about how its wired though. I think your idea of having a switch to control which tank the gauge is reading is an effective solution.

-I think the GX and 200 charcoal canister are the same from looking at the photos. The US spec charcoal canister has a leak detection pump attached - that is the thing with the electrical connector on it. I don't see it on any non-US spec vehicle parts diagrams. The third pipe on the US spec filler is just a vent to atmosphere for the charcoal canister and connects through the filter sub assembly, I don't think you need to retain the third pipe as long as you can find a dry place to mount the vent to atmosphere, expecially since you relocated the canister to the engine compartment. The other two connections go the the tank(s) and engine vacuum.

-Did you find a source for fittings for the charcoal canister connections? I know they are push to lock but I think they just need to be fuel safe and air tight. I was considering just using fuel safe hose and constant tension clamps.

Link to my thread with some things I have been working through:

Prado 120 sub tank in a GX470 - has anyone done it? Well I’m gonna try!

12/1/2021 edit: swap is complete and functional :cool: Has anyone added a Prado 120 sub tank in their GX470? I know there are aftermarket options available but the possibility of using the OEM tank is interesting and seemingly (possibly?) less expensive. Adding this sub tank increases the...

forum.ih8mud.com

Its good to see that you and I are coming to a lot of the same conclusions.

 

[grinchy]

I just read the entire thread, its funny that I came across this today as I have been investigating in parallel what it will take to install a factory Pardo 120 sub tank into my GX470. From what I can tell the two vehicles have very similar sub tank systems.

-The Prado fuel gauge has a green fuel light and reads full to half full on the sub tank sender, then the green light lights up and the gauge jumps back to full and reads the main tank sender. I assume you would have to buy the entire cluster to get just the fuel gauge but if you had both clusters you could probably swap it in - who knows about how its wired though. I think your idea of having a switch to control which tank the gauge is reading is an effective solution.

-I think the GX and 200 charcoal canister are the same from looking at the photos. The US spec charcoal canister has a leak detection pump attached - that is the thing with the electrical connector on it. I don't see it on any non-US spec vehicle parts diagrams. The third pipe on the US spec filler is just a vent to atmosphere for the charcoal canister and connects through the filter sub assembly, I don't think you need to retain the third pipe as long as you can find a dry place to mount the vent to atmosphere, expecially since you relocated the canister to the engine compartment. The other two connections go the the tank(s) and engine vacuum.

-Did you find a source for fittings for the charcoal canister connections? I know they are push to lock but I think they just need to be fuel safe and air tight. I was considering just using fuel safe hose and constant tension clamps.

Link to my thread with some things I have been working through:

Prado 120 sub tank in a GX470 - has anyone done it? Well I’m gonna try!

12/1/2021 edit: swap is complete and functional :cool: Has anyone added a Prado 120 sub tank in their GX470? I know there are aftermarket options available but the possibility of using the OEM tank is interesting and seemingly (possibly?) less expensive. Adding this sub tank increases the...

forum.ih8mud.com

Its good to see that you and I are coming to a lot of the same conclusions.

Thanks for the thoughts and feedback! Good luck with the Prado 120 adaption.

- yeah I don’t value a completely accurate fuel gauge vs adapting to a new cluster in km and costing another $1500. I’m going to run the sender up front and see what I can get to work easy

- agree that the air filter portion out of the charcoal canister and third pipe on the filler (air filter from canister to filler area) is not required. I do not plan to retain this. I do plan to run the air filter up in the engine area (room availability TBD)

- I'm going to use brass barbs and clamps to convert the evap connections as necessary. i want it to hold vacuum so it will not throw DTC codes during its use and during the frequent self tests it performs. I have a bunch of 5/8", but I see that other sources are using 3/4' for this. I can make the 5/8" work so will go with that, may recommend the 3/4" depending how much a PITA it is.

 

[grinchy]

-The Prado fuel gauge has a green fuel light and reads full to half full on the sub tank sender, then the green light lights up and the gauge jumps back to full and reads the main tank sender. I assume you would have to buy the entire cluster to get just the fuel gauge but if you had both clusters you could probably swap it in - who knows about how its wired though. I think your idea of having a switch to control which tank the gauge is reading is an effective solution.

thinking about this. We do have the data to do this, we have a resistance range on two wires and could do some led lighting and even source signal switching to match with a raspberry pi or similar.

for example
resistance high on sub tank and high on main tank - switch to sub tank and show on gauge
resistance low on sub tank and high on main tank - switch to main tank and show on gauge, light led green
resistance low on sub tank and low on main tank - light led red

 

[grinchy]

I’ve got the bolt and stud off the filler pipe, and have it moved down a couple inches. Trying to get the filler vent tube clamp off. Its a fancy irreplaceable press both buttons while pushing a hose with no flex one way and a pipe with no flex the other.
Other fuel tank vids say to pull the filler down to get some range of motion, but the filler seems quite happy where it is.
Can’t break the clamp, would have to buy a new main tank, so taking a break to reassess for tomorrow.

 

[CharlieS]

That is a sign of hard earned wisdom: knowing when to stop before breaking something. Good luck when you get back to it.

 

[grinchy]

Not much to show for six or so hours of fiddling. Morning spent dorking with the vent clamp. After trying several increasingly elaborate mechanical pinching designs I ended up having to weld up a tool.
Old pliers plus some narrow nuts. With this and a rubber band on the handle to hold it closed, I could guarantee that the pinch was on and pried it off. Still took more pulling pressure than I preferred. I have no idea what type of human would have the narrow little fingers, strength, and coordination to take this off. Anyhow, it does any matter because . . .