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GAS TANK

Posted: Sun Mar 25, 2012 6:12 pm
by vinnytruck
Hi Guys, Hope all is well...can I put rubber tubing around my gas tank straps? 1- to save the new tank from possible strap wear, or do I need not worry. 2 does the gas tank have to be grounded and how do I do that?-----------there are only 2 hoses on my tank, 1- metal gas line to the front,1-fill lg. hose, 1-small hose leading from the tank up to the metal fill tube where the cap is. My question is does the tank need a open air hose or does the tank need to be closed for suction for the pump? (pump is the orginal ac military style)Thanks again VT

Re: GAS TANK

Posted: Sun Mar 25, 2012 7:55 pm
by Cal_Gary
I tried, using plumbing pipe insulation but falied because I didn't have enough leverage to get the bolts started. By the time I figured out, and fabbed up a leveraging piece of pipe I already had the tank sitting in place and didn't want to pull it back down.

The tank needs to be vented-check your cap to see if it has the switch on it. I can't answer regarding the manual fuel pump, as I run an electric.

Some guys use a ground strap on the tank; however I will confess that my fuel gauge is still wacky, even with the ground strap.
Gary

Re: GAS TANK

Posted: Sun Mar 25, 2012 10:20 pm
by SOTVEN
HELLO. I USED SILICONE CAULKING ON THE TANK WHERE THE STRAPS TOUCH IT. THE CANVAS WEB WAS SHOT, PLUS I DID NOT LIKE THE IDEA OF TRAPED MOISTURE THERE. ONCE I PAINTED THE TANK, I APPLIED SILICONE AT A THICKNESS SIMILAR TO THAT OF THE WEBBING ON BOTH ENDS, AND THEN I LEFT IT TO CURE FOR 3 DAYS BEFORE MOUNTING. THIS WAY, THE SILICONE BECOMES A HARD RUBBER, THAT IS ONLY ADHERED TO ONE OF THE SURFACES, NOT BOTH. I HAVE NOT CONNECTED THE FUEL GAUGE YET TO SEE IF IT NEEDS GROUND, BUT I DOUBT THERE WAS ANY WITH THE ORIGINAL WEBBING SANDWICHED INBETWEEN. AS FOR THE VENTING, IT IS NESSESARY. BESIDES THE MANUAL GAS CAP VENT WHICH IS THERE TO PREVENT WATER CONTAMINATION DURING DEEPWATER FORDING, THERE IS A PERMENANT VENTING COPPER TUBE RUNNING ALONG SIDE THE FUEL SUPPLY, AND IS CONNECTED TO THE AIR INTAKE ELBOW. I HOPE THIS HELPS :)

Re: GAS TANK

Posted: Tue Mar 27, 2012 8:29 am
by vargaspj
Any gas tank must always be bonded to the vehicle frame to discharge any static charge that accumulates on the gas tank and also to discharge any static charge that may be on the fuel fill nozzle at the gas station. Some stations here have a label on the fuel system pump that instructs you to touch the tip of the fill nozzle to the metal of the gas tank fill tube before pumping gas to get rid of any charge before you start filling up with gas.
I reran the fuel tank vent line as shown in the tech manual to the air intake horn. That way the gas tank is always vented and I don't have to worry if the gas tank cap is accidentally left in the "closed" postion.
My fuel tank cap has 2 positions; normally loose (open vent) for normal operations and tightened down (closed vent) for fording (and then put back in the open position after the fording is complete). I believe if the gas tank is not somehow vented the truck may after a while stall due to the restriction of the fuel flow from the tank to the carburetor due to vacuum buildup in the gas tank.

Re: GAS TANK

Posted: Tue Mar 27, 2012 1:33 pm
by SOTVEN
HMMM.... INTERESTING. I TOO THOUGHT THAT GAS TANKS SHOULD BE GROUNDED FOR THE AFFOREMENTIONED REASONS, YET IN MY M, I DID NOT FIND A GROUND. I DO NOT THINK THAT THE STRAPS COUNT, SINCE THERE IS THAT WEBING INBETWEEN, SO THE METAL DOES NOT TOUCH METAL. UNLESS THE AIR VENT THAT GOES TO THE ELBOW IS ALSO THE GROUND?? IT IS COPPER, AND REACHES THE ELBOW WHICH IS ALUMINUM, WHICH MOUNTS ON THE ENGINE WHICH IS GROUNDED? COULD IT BE?

Re: GAS TANK

Posted: Tue Mar 27, 2012 6:39 pm
by vinnytruck
Hi Guys, Thanks for all your comments...This is what I am going to do." I think this will be logical". I need to ground the gas tank, I will purchase a grounding strap and some how attach it somewhere. I will cover the straps with inner tube material. 2- I am going to run a metal line from the gas tank-(I will have to drop the tank AGAIN, remove it and get a 5/16 tubing right angle connector from the top of gas tank(need to get welded) and run from the gas tank to the fitting on the top of the engine or the gas pump, I dont know which...it looks like in the diagram the vent tube goes from tank to the top of engine? My fuel pump comes back this thur. I will try mounting it and find out the lines and holes on it. I will always accept more advise or comments on this area so please tell me. Thanks VT

Re: GAS TANK

Posted: Wed Mar 28, 2012 10:54 am
by WarrenD
I'll see if I can get some time tomorrow evening to get under mine and trace out the vent line. I just had my tank out last fall and didn't use anything over the straps. The re-cond tank has a coating inside and out so should be good for many years. There wasn't any room for any other material between the straps and tank anyway. Mine is garaged, so I'm not worried about rust. Tank has a good ground, fuel gauge works well, other than a lack of dampening. Even with the tank baffles, it bounces around alot when driving.
The gas cap has 2 positions, the first stop is the vented one, you should use this when driving. The second stop is the fording position which I think closes off the cap vent and shifts venting over to the hard vent line running out the top of the tank. I'll see if I can find where it ends up, I know it's not at the fuel pump. Fuel pump lines are fuel in/out on top and vacuum in/out on the bottom. Vacuum in would not be the fuel tank vent as that would create a vacuum in the tank.

Re: GAS TANK

Posted: Wed Mar 28, 2012 2:25 pm
by vinnytruck
Hi Warren, about my gas cap, yes you and another are right. It has two positions and I will, when this trucks starts will be using the open position thanks to you all...I didnt know that (still learning) About the straps I went to a old car restorer near me and he said you can wrap them if you wish no big deal they will last.(and tank) The grounding... THE TANK MUST BE GROUNDED, I am using a braded universal groundstrap with 2 eyes. I am going to bolt on the frame and go to the tank lip with a A frame clip nut with screw. About the vent line I am going to tap a hole in the filler neck (high) with a loop in the line so no gas gets down the tube to somewhere I still dont know where to connect, He said his guess is it will termanate at the manafold or a charcoal filter.VT

Re: GAS TANK

Posted: Thu Mar 29, 2012 3:30 am
by T. Highway
VT,

The fuel tank vent line is connected to the front of the intake elbow, in the lower part of the elbow but not on the bottom. I can post a picture of it later today if you would like.

I wouldn't put the vent line back into the filler neck. If you close the cap for fording or accidently close it, the tank would be under a vacuum.

Bert

Re: GAS TANK

Posted: Thu Mar 29, 2012 6:31 am
by vinnytruck
Thanks Bert for your reply, PLEASE post a picture, (if you can) its true its worth a thousand words. I guess your right about the filler tube, I am trying to not take the tank down AGAIN...and looking at all sort of angles. ***Hey guys the pump came, what is the positioning for the motor so I dont break the pump arm??? THANKS VT

Re: GAS TANK

Posted: Thu Mar 29, 2012 12:43 pm
by Tanner
Does the TM show a ground strap used on the tank? I don't recall one on my truck...

Re: GAS TANK

Posted: Thu Mar 29, 2012 1:28 pm
by WarrenD
I couldn't find where my vent line is supposed to go as it ended in the frame rail under the passenger's seat. Must have been disconnected at some point and never got put back. Hopefully someone else can step in. My tank didn't have a ground strap, either the old one nor the new one. Plenty of metal to metal contact!

Re: GAS TANK

Posted: Thu Mar 29, 2012 5:04 pm
by T. Highway
VT,

Here are two pictures of the fuel tank vent lines connected to the elbow between the air cleaner and carb. Hope this helps.

The pen is pointing to the fitting.
Image

The vent line is "R" in this picture
Image

These can all be found in your TM.

Bert

Re: GAS TANK

Posted: Thu Mar 29, 2012 5:31 pm
by vinnytruck
Burt, Thanks so much for your time and the pictures. This will help us alot. What tm are you talking about can you provide a #. P.S. Can you tell me what is proper here, do I write Bert or T. highway, thanks again VT

Re: GAS TANK

Posted: Fri Mar 30, 2012 4:04 am
by T. Highway
VT,

Bert is my name. I will get you the TM number tonight.

Bert