Removal of 12.5G LRA Tank for replacement of Evap Canister (1 Viewer)

[Romer]

Aux Tank Removal to replace Evap Canister

I have the LRA 12.5 Gallon Aux Tank, built in early 2018, so it may be an older version.

I was getting the following Codes repeatedly, in addition the 4LO and Trac lights came on which prevents switching between 4WD Lo to Hi or vis a versa depending ion which one you are in

• P043E catalyst temperature sensor circuit low (bank 2 sensor 2).
• P043F catalyst temperature sensor circuit high (bank 2 sensor 2)
• P2401evaporative emission system leak detection pump control circuit low.
• P2402 evaporative emission system leak detection pump control circuit high.
• P2419 evaporative emission system switching valve control circuit low.

Using an OBD reader to clear the codes enables normal operation and even with the 4LO light on, the truck runs fine.

I assumed it was the Evap/Charcoal Canister discussed in this thread, part #77740-60471 Anatomy of P0456 - Small Evap Leak - https://forum.ih8mud.com/threads/anatomy-of-p0456-small-evap-leak.1279152/

I wanted to try a few easier things before dropping the tank, which I knew would be several banana job

@TeCKis300 generated the above thread and several others I found useful in this area. I first replaced the Charcoal Filter part # 77706-60040 and the Vent K&N 62-1020 vent filter. Mine was caked with dirt and had actually disconnected from the hose. This thread discusses the issue and fix. I did the filter because it was exposed to an open hose and fairly cheap while “I am in there”. You likely don’t need to replace the Charcoal filter.

Charcoal Canister / LRA Breather Fix - https://forum.ih8mud.com/threads/charcoal-canister-lra-breather-fix.1248188/

TeCKis300 also did one on heat effects on the fuel system and fixes for that. I plan on adding those modifications after I complete this activity. DIY Fuel Heating/Boiling Mitigation - https://forum.ih8mud.com/threads/diy-fuel-heating-boiling-mitigation.1318529/

As mentioned, I changed the Charcoal FILTER (not canister) and the Vent line. I also replaced my Gas Cap part # 77300-06040 and the Vacuum Switching Valve part #25860-0S010 (VSV), the VSV was discussed in this thread The P0441 Thread - https://forum.ih8mud.com/threads/the-p0441-thread.1289965/

None of the above prevented the codes so I resigned myself to replacing the Evap/Carbon Canister. That job is complicated because I have a 12.5 Gallon LRA tank installed by Slee. After putting mine in the decided they wouldn’t do another 12.5 one in as it was a pain. Not 100% sure it was my specific tank, but Slee posted somewhere they did only 1 so I am ASSUMING it was mine. They still do 24 and 40 gallon tanks though.

Okay, time to do some research. I reviewed all the install threads here. The first linked thread by @TeCKis300 above with code P0456 was very helpful. I started posting in there, but was recommended to do a separate thread on the process.

I also reviewed @OTRAMM Youtube video on the tank install



This was very helpful as well, BUT I am removing someone else’s install to replace the canister and putting it back the way I found it so good reference info but need to expect some things will be different.

In preparation I ordered this from Amazon to help get the tank up and down. Having a tool was recommended in one of the threads I linked

https://www.amazon.com/dp/B06XNZ5GV6?ref=ppx_yo2ov_dt_b_fed_asin_title

 

[Romer]

Step 1- Remove Spare Tire- Complete

Crank it down and take it off. Done! It was a bit rough and caked with dirt so will clean this up later before reinstall. No hurry since this was my 2nd spare. I still have the spare on my Slee Bumper.

Step 2- Remove the Spare Tire Carrier Assembly - Complete

• To get access to all the bolts, I had to remove the exhaust pipe and Resonator. After reading some other threads where people had removed the Resonator and then plumbed behind the spare tire, I decided to cut the Resonator off. I will have a muffler shop weld on an exit pipe when I am all done. I drove it and heard no difference. That mod is discussed here Resonator Chop Roll Call - https://forum.ih8mud.com/threads/resonator-chop-roll-call.1143769/
• I removed the 4 bolts holding the cross beam carrier to the brackets mounted to the rail. 2 of the bolts were hard so I soaked them over night with PB blaster and them cam off easy the next day. Awkward to get the 12M socket on the bolt, Hold the wrench over the frame and use your other hand through the small slots to guide socket on bolt. It took a while

• I could not get the carrier off though, it was in there tight, so I removed the two side brackets using a jack to hold the carrier so it wouldn’t fall on me
• Note the side bracket bolts could be in by Rivnuts or via other methods. I lost one bolt into the frame and will replace it with a Rivnut. I put the nuts back on the 5 remaining bolts to keep them from moving into the frame. If you have rivnuts then you would have the bolt head vs nut here which would be a different configuration. Use hand tools with Rivnuts.

At this point, the vehicle is fully drivable with no limitations as I doubt I need a 2nd spare until next wheeling season. Taking time to review and develop plans going forward

 

[Romer]

Step 3- Drain Aux Tank- Complete

With a gas can and funnel below, remove drain plug and front right (looking forward) side of tank. Replace tank after draining approx. 2 gallons

Step 4 – Remove Spare Tire support bracket from top of tank (Tire rests on this to prevent damage) and wheel well cover - Complete

• Remove cover in rear passenger wheel well. There are 5 T30 bolts and 3 (maybe 4)Clips to pull out. 1 clip is tucked up in the indentation near the bottom. Good to have extra clips in case you break one. I took one to the dealer and they matched it up, I don’t know the part number. Remove panel out for access to filler and other hoses. There are two pieces that make up this cover. This will provide access to the hoses from the fill tube to the tank.

• The spare tire support bracket comes off with two 12 mm bolts

Step 5 – Remove Hose Connections

• Before removing the tank, need to remove the fill hose from the fill tube to the tank over the rear passenger side frame rail. I was not able to get this one off. I got it to turn using a heat gun, but was unable to get it off, so I cut it between the two metal peaces and then removed it after the tank was removed.

• Remove the 5/8” vent line at the Fill tube.

• Remove the fill hose from the fuel filter/Pump. This is the hose that comes from the front of the tank which is where I removed it

Step 6- Step 6 is always relax and enjoy a beer. A light beer since you are not done yet

 

[Romer]

Step 7 – Remove Tank - Complete

• Place the lift jack under the tank and begin to remove bolts. May need to adjust placement of jack to get full access. One step said side brackets would need to be removed to get tank in. Tight fit requiring lots of adjustments I read

• 3 U bolts (2 nuts each) in front
• Side Bracket bolts 2 per side
• I had to remove side brackets
• Lower tank slightly until can get access to the top and remove sender wires. On mine, the power was a slip on connector and the ground was tied to a 7 mm nut on top of the sender

yes the top is really dirty. I will clean it off before re-installing

• I had to unbolt the 7 pin plug to make access. Glad I cut the resonator off, nut sure how I would have gotten it out with the exhaust there.
• Lower tank out of the way. This takes some jockeying the tank around
• Note: several of the bolts will need to be replaced with Rivnuts. Mine were weird with a strap welded at end sticking out a notch in the frame to keep them in place while tightening. A couple of straps broke and two bolts sliped back and another still needs to be removed from the nut on a bracket

Step 8- Remove and replace Evap/Charcoal Canister- Complete

• First disconnect the harness connector. I had a hard time with this one.
• There are two hoses on with hose clamps I removed.
• 3rd hose has a special connector. I removed the green clip and spent quite a bit of time jockeying this around to get it off. I am sure I missed something in doing it correctly. Any tips here for others would be helpful
• Take off 3 12 mm bolts.
• Use screwdriver to separate canister between top and bottom of rear bed. There is a plastic clip here and it can be broken off as new one comes with clip
• Lift canister out noting the "slip in pin" on the drivers side next to one of the bolts removed
• Install new one

 

[Romer]

Step 9 - Reinstall Aux Tank - complete

• Man what a pain. I ended up cutting off the rear exhaust hanger as I couldnt get the tank around it lying on my back by myself. The video in post 1 talked about that the hanger gets in the way. I spent an hour trying to go around it and finally gave up. I don't need it since I removed my resonator
• Lots of adjusting jacking adjusting jacking etc. Took me about 4 hours to get it all in place and bolted up
• got it up in position, installed the tank brackets and then raised the rear with a jack to get the U bolts going
• Tighten all bolts
• Fuel Vent, Fuel delivery hoses went on easy
• The original fuel line was damaged so I replaced it with a similar size from GM. This was my last step before putting the wheel well cover back on.
• I could not move the hose from the fill tube to the tank. Part of it was I couldnt get it to seat properly. The hose is very stiff. I used a heat gun and it didn't help
• I used 1-3/8" Inch (SOFT WALL) Gas, Oil, Diesel Fuel Filler Hose (SOLD PER INCH) - https://www.fillernecksupply.com/1-3-8-inch-soft-wall-gas-oil-diesel-fuel-filler-hose-sold-per-inch/ and a hose cutter from Amazon. It went on fairly easy. Install on the tank filler pipe first and adjust as the tank gets into position before bolted down

As you see later in the tghread I had to remove the tank due to leak codes. That ended up being caused by the main tank fuel vent hose not being fuloly installed. I also crusghed the connector the first time I put it in and that threa codes, so make sure the connector is out of the way. See later posts for details

 

[Romer]

Step 10 – Reinstall Spare Tire Carrier – Assumes carrier cleaned and lubed and also missing bolt replaced with Rivnut -Complete

• Using jack lift carrier cross bar into place and adjust while adding brackets back to frame
• Reinstall the 4 bolts mounting carrier cross member to brackets

Step 11 - Reinstall the spare tire - Complete

Step 12 or 2nd Step 6 - Enjoy a beer and cigar. This one doesn’t have to be light as you are done

 

[grinchy]

3rd hose has a special connector. I removed the green clip and spent quite a bit of time jockeying this around to get it off. I am sure I missed something in doing it correctly. Any tips here for others would be helpful

The green evap clips are pretty breakable and I couldn’t find them available to buy separately. To remove, pry them up to 1/2 way or just beyond, then the hose can be tugged off the fitting. Leave the green clip in the fitting. If you pull the green clip all the way out it may break on removal or reinsertion in the fitting.

For install push the hose on and then reset the clip down.

 

[Romer]

Updated post 5, mostly complete short the main fuel hose

 

[isthatalexus]

@Romer outstanding compilation and step-by-step thread. Would include in pinned/how-to compilation thread.

 

[Romer]

Got the tank installed and immediatley got a new code, P0453 P0453 Evap code - https://forum.ih8mud.com/threads/p0453-evap-code.1125562/

Everything else worked. Tank had no leaks. Sender worked. Filled tank with 5 gallons and then transfered to main tank

Since I can't reset this, I can't go into 4LO

Pretty much a hard code. Clears for half a second and comes right back. It even comes back when the engine is off and in accessory mode. Not sure how the algorithm for this code works. It says it detects high pressure, which I THINK means there is a leak and the system is trying to compensate. Not sure on that.

I checked the hoses and didnt find any issues to the tank. I have to drop the tank to get to the Evap canistar

Ran a report and the Absolute System Evap Pressure was 503.68 in H20, which is high based on what I can find. Whole report attached. Permenant codes are what I was trying to fix . Maybe someone else will see something. I was at idle when I ran it after driving 15 minutes.

Dropping the tank again. I kept the old caansister so I can use it to help troubleshoot.

I ordered some hose plugs to help troubleshoot this in a closed fuel system without having to put the tank in. That will make it easier to resolve

 

[grinchy]

That’s unfortunate. Interested to see what this ends up being as root cause.
This code survives a battery pull?

 

[Romer]

That’s unfortunate. Interested to see what this ends up being as root cause.
This code survives a battery pull?

I didnt pull the battery sincee I should be able to clear it with my reader.

Doesn't matter now as I am in process removing the tank. Maybe I will see all the jockeying I did with the tank pulleed a hose or cracked something.

Here is my plan

• Inspect for damage or loose hose on Canister. Look at connector for bent pins. If damaged, correct and see if problem fixed. If not then;
• Cap open fuel lines (Parts come Tuesday)
• Check codes
• If not present, then drive for a bit with fuel lines capped and see if original codes come back
• If codes still present, swap in old canister and see if get the same code.

Then reasess. If codes go away with new canister, take a closer look at tank install. If new unit still has codes and old one doesn't, I know I can order the electronics section for the canister at a lower cost and replace or look at using a mix of old and new canistar or if steps don't change things, pull battery

Typing stuff here helps me think through the process to be methodical in troubleshooting. Thanks for reading

 

[Romer]

found the problem setting the hard code. A connecrtor got smashed putting the tank in. This is from the Evaap Canister to the main hardness. Fortunately, the big breakaage was on the canister side. I took the cable off of the old canister and put it on. I was able to clear the hard code.

I will be mindful of it putting the tank back.

 

[TeCKis300]

found the problem setting the hard code. A connecrtor got smashed putting the tank in. This is from the Evaap Canister to the main hardness. Fortunately, the big breakaage was on the canister side. I took the cable off of the old canister and put it on. I was able to clear the hard code.

I will be mindful of it putting the tank back.
View attachment 3798393

Glad you found it and it was a clear issue rather a more subtle hard to find problem.

 

[grinchy]

Glad it was easy to see. Bummer about the 2nd round trip install.

 

[Romer]

I put it all back together. Took it for a drive and put 5 gallons in trhe Aux tank. So far so good

Make sure that connector is out of the way when putting this tank in

 

[gasman4u]

I put it all back together. Took it for a drive and put 5 gallons in trhe Aux tank. So far so good

Make sure that connector is out of the way when putting this tank in

That’s good to hear it fixed your CEL codes! The same connector got smashed on mine and kept generating the damn p2420.

 

[Romer]

Just some thoughts after recovering for a day Boy I am glad I am not a mechanic. Lots of aches from muscles not normally used. I am guessing it would have been a lot better if I wasnt doing everything from my back under the vehicle.

• Obviously need to be careful of that connector. I used duct tape to have it out of the way while I installed the tank. Only needs to work during this step
• The Exhaust has to come off. Either remove from the muffler back for a temporary solution or cut at the next hanger back. I cut mine off
  • The exhaust tip has was pretty banged up from wheeling
  • It was pretty obvious to me that a significant amount of the heat transfer from exhaust to fuel comes from the reasonator sitting right below the Aux tank. Removing would greatly help with this.
  • There was a thread mentioned earlier where others removed it and noticed no difference in sound in the truck. I found that to be true so far. No long highway trips yet
  • I intend to right angle it just behind the rear tire which should prevent any future damage
  • Seemed like removing the resonator was a win-win
• The rear hanger for the exhaust was a real pain and I wasn't able to get the tank in with it there. Likely one of the causes of the broken connector as I tried all ways to get the tank up and over for several hours. Since I had removed the Resonator, I cut the rear hanger bracket off and it went fairly quickly after that
• Installing thoughs; Use the lift I bought to get it into approx position. Move over the exhaust with the spare tire protector (It can get hung up here). Get it so the rear bracket mount on the tank lines up close to where the brackets will mount. Then put the rear brackets on to the frame, but do not attach the tank to them. This allows the tank to rest on the brackets and still be movable while you get everything else buttoned down. To put the brackets on the rear frame, you have to be able to lift that part of the tank to the top of the frame rail.
• After you get the Fuel line attached, the U bolts then bolted up you can bolt up the tank to the rear brackets
• The main fuel line is much easier to get back on the tank side. First time I took it off the filler side and it was a real pain to get it on.

 

[Romer]

There were a lot of useful threads that helped me through this. I added a section in the 200 series FAQ thread in the Repairs/Maintenance section

 

[TeCKis300]

[*]It was pretty obvious to me that a significant amount of the heat transfer from exhaust to fuel comes from the reasonator sitting right below the Aux tank. Removing would greatly help with this.

Yes, and I double layered some heat insulation and sheilding there. With the amount of idling wheeling with a larger group, this area had to be a factor with boiling fuel.

I'm tempted to hack off the resonator. Good to hear the sound doesn't appreciably change.