Fisherguy

Okay, this is where I left off with my AD100 install:

https://www.dieseltruckresource.com/...d.php?t=204909



I ran the tank low again and at just over ¼ tank my FP gauge was doing what I expected, dropping to zero till the engine return line fills it enough that the AD pumps more fuel with the excess going to the filler neck, once the canister empties it's pumping air, the gauge drops and the whole thing repeats.

So my plan was to drop the tank again and modify the Liberty canister by adding a draw straw to use fore the AD return so it's filling the canister rather than pumping the excess fuel back into the tank. I ordered a draw straw from Richard at Glacier as shown here, note this one uses a bulkhead fitting for the seal. I felt this would give me a better seal than the one that comes with the AD that uses a grommet as a seal. Also the one from Glacier comes with a black tube you can bend to the shape you need which comes in handy as you'll see later.






I ran the engine with the AD return pumping into a 5 gallon can, after a few minutes I'd emptied about 4½ gallons from the tank,. this made taking it out and re-installing easier. I don't use a floor jack, just get under it (after undoing everything on top) and undo the clamps and lower it down, after the first 4 times I'm getting good at this!


After dropping the tank and removing the canister the first thing to do to be able to grind the ribs off the inside (bottom) of the canister is to remove the fuel gauge sending unit. Using a screw driver you can bend the tabs of the unit 1 at a time then the whole unit will simply pull off the canister:





Here's some pictures showing how I ground the ribs using a flat grinding wheel and a cylindrical one so I could grind the ribs even with the surface, you can see the fuel gauge unit hanging in the last of the 3:









I finished off the outside (top) surface of the canister by sanding with some emery cloth to make it flat as possible so the o-ring of the bulkhead fitting would seal well then I drilled the 1" hole with a hole saw:





The canister with the bulkhead fitting installed:

Fisherguy

I could not extend the draw straw straight down from where I mounted it because the fuel gauge sending unit would make it impossible for the tube to extend into the canister so I heated it up with a propane torch and was able to bend it so the tube would go into the other side of the canister as shown


I measured and found the springs compress about 1½" when you put the canister in the tank, so I trimmed the draw straw so it just passes the black support, when installed the straw will be about 2" from the bottom of the canister:






Ready to be put back into place. I had to add a piece of hose to extend the AD return so it's easier to put the fitting and hose on first rather than trying to tighten it once installed, I used a ½" barbed fitting from the plumbing department of the local hardware store and hose clamps to join the hoses together. Also I never was able to get the Dorman fitting off the AD supply line so pre-installed that hose as well.






With the tank installed:
(hmmm, better check that red tab on the wiring connector tomorrow, looks like it's not in all the way)




I dumped the 4½ gallons back into the tank and started it up. The FP gauge sat at zero till the engine return filled the canister, then the gauge went up to 17 pounds and didn't move, everything seemed to be working great, I was very happy and had a celebratory tasty beverage while I cleaned up the shop. I went for a drive, the fuel gauge was right at E but the FP gauge never went down, it only varied usual as I drove. The LOW FUEL light came on and with the overhead DTE showing 60 miles I went to fill the tank, 137 litres and $204.10 of my hard earned CDN money, OUCH!

(Fuel up here works out to 5.64 per US gallon)

So now I'm happy, I have more fuel pressure than I'll ever need and no problems running the tank low, WOOHOO!


Thanks to Mark and Charlie for all their help, especially Mark who I bugged a lot for help and advice!

StealthDiesel

Fisherguy, great post and pics...

I've been following your fuel system engineering posts & research for a while now. Nice work.

Just to confirm: You are using the drawstraw for your AirDog pump's RETURN flow back to the tank?

The original Liberty fuel cannister's output is still the outlet?
The blue hose in your pics is the output of the fuel cannister and the input to your Airdog pump?

Joe... (Grew up in B.C., SFU grad many years ago!)

4_play_ram

I have been patiently waiting to see your update to this problem. I will be taking notes, and will be coping some of your ideas (If you don't mind) this is exactly what I want to do. Looks awesome, nice clean install. Hope everything works for you. sorry that you had to do all the grunt work, and the rest of us can breeze through on our installs. Cheers
Jon

Fisherguy

Thanks Joe and yup.

Yup and yup.

The blue hose feeds the pump, the black hose is the AD return to the canister and new draw straw.

I hear there's a restriction in the canister feed where the fuel goes up to the canister lid and out the 90º bend, it's only ¼" or something and is sposed to be okay for the 100 but too much of a restriction for the 150. The AD100 is more than enough for my needs and originally I was hoping to not have to use any draw straw, but this seemed to work well.



Sure Jon, no problem, hopefully this helps out a few people.

Sandaholic

Good for you! Glad you got it figured out, it'll be nice not having to worry about it anymore. Thanx for sharing!

53 willys

Nice job Will!!! I am glad you got it figured out...and I am even more happy you are happy with your set-up...Nice job!...great pics too.

kanuckle head

Glad U concord that problem that mod will B next in line for me now I have a direction to follow
Listen I live close since your a pro @ dropping your tank you can give me a hand with mine I'll supply the Wobblies !!!
Maybe just trade of for west coast fishing for hali's

53 willys

Will is that your o-ring smashing out of the side of the fitting in this pic?

Fisherguy

No, I put a little gasket goop on the o-ring, that's it oozing out.

BTW, I have a socket for the top part of the fitting 11/8" but not one for the bottom, it's 1¼" I think, was a little awkward tightening it up, hard to get a wrench on.

Kanuckle, what size is the motor on your boat, it looks HUGE!

kanuckle head

I replaced the 225 2 stroke Yamy with 250 4 stroke Suzuki. Do you do any interior lake fly fishing my buddy just came back from the Merritt plateaus & got a couple of nice trophy Bows I'll be heading out in the next couple weeks when the damsels hatch

Fisherguy

Yah, lake fly fishing is my big thing, we leave in 2 weeks as well for a 3 week trip, back to work for 2 weeks then off again for 2 more weeks.

My son's a guide on the Dean so I go there every year, check out the lodge:
http://www.lowerdean.com/

kanuckle head

Ya summer run steelies & the odd tyee on the Dean is quite pristine jet boat or heli in & Spey cast with Grizzlys. I got buddy's from the Totems that hit the Dean regularly & Wavey from M&Y who I went to school with gives me all his feeds

WILDBILL01

This mite sound dum but wy wouldnt you use the return line allready there.

Fisherguy

Pardon?
The one that's already there is the engine return line which is still hooked up to the CP3, with the AirDog, Fass or whatever you need to plumb another line for the excess the pump puts out that doesn't go to the engine.