by oo3 October 1st 2008, 17:57i have a very slight leak from my fuel sender unit on the gas tank - another vanner had a similar problem mentioned in a different topic thread - i also have a little play where the tube enters the plate - it was mentioned the best method is to solder this - so what method is used to solder this - plumbers tools, map gas torch and solder? - or ? - and any special methods to remove sender unit - i have a manual on cd but i cant seem to find any removal of sender - thanks - oo3
3 posters
fuel sender leak
oo3- Number of posts : 290
Location : new orleans
Registration date : 2008-06-01
donivan65- Governor
- Number of posts : 12246
Location : San Diego, California
Registration date : 2008-05-12
It's exactly like plumbing,,,,some flux,,,,,solder,,,,propane torch. But undo any plastic washers or spacers around it that might melt and I would put the tube part in a vice to stop the heat from getting into the resistance unit on the float
,,,,,,and do it off the vehicle,,,
,,,,,,and do it off the vehicle,,,
itruns- Number of posts : 1605
Location : Chicago, IL
Registration date : 2008-07-03
I think Alex used JB Weld to seal a gas tank leak.
Solder won't take to anything but nice shinny steel or copper. Use 50/50 tin/lead (if you can find it), it fills/builds better. Mapp gas is probably too hot for a beginner. I like Laco paste flux.
To remove the sending unit you have to drop the tank. The gas weighs a lot even if it's a few gallons. I jacked the back of the van up and siphoned it out via the fuel pick-up. Have a couple/few empty fuel jugs around.
I recently changed the sending unit on my A100. I got the new one from George at the Yahoo group (the price was in line). You might want to consider getting the new assembly. I believe Nate says it's a modified for the A-bodies. George also has the 90 degree 1 3/4" hose for the filler pipe connection.
Here is a link for the grounding strap, retaining ring (that simply unscrews with a hammer and old screwdriver), gasket, filter sock, and float.
http://www.yearone.com/serverfiles/fbshopmain2.asp?input=FD58862&SM=1&SC=&goBtn.x=19&goBtn.y=2
Here is the page with my post on removing the tank:
https://vintage-vans.forumotion.com/between-the-seats-a-f16/fuel-gauge-off-t1388.htm
Please, take Don's advice - DO IT OFF THE VEHICLE
Good Luck and let me know if you have any more questions.
Solder won't take to anything but nice shinny steel or copper. Use 50/50 tin/lead (if you can find it), it fills/builds better. Mapp gas is probably too hot for a beginner. I like Laco paste flux.
To remove the sending unit you have to drop the tank. The gas weighs a lot even if it's a few gallons. I jacked the back of the van up and siphoned it out via the fuel pick-up. Have a couple/few empty fuel jugs around.
I recently changed the sending unit on my A100. I got the new one from George at the Yahoo group (the price was in line). You might want to consider getting the new assembly. I believe Nate says it's a modified for the A-bodies. George also has the 90 degree 1 3/4" hose for the filler pipe connection.
Here is a link for the grounding strap, retaining ring (that simply unscrews with a hammer and old screwdriver), gasket, filter sock, and float.
http://www.yearone.com/serverfiles/fbshopmain2.asp?input=FD58862&SM=1&SC=&goBtn.x=19&goBtn.y=2
Here is the page with my post on removing the tank:
https://vintage-vans.forumotion.com/between-the-seats-a-f16/fuel-gauge-off-t1388.htm
Please, take Don's advice - DO IT OFF THE VEHICLE
Good Luck and let me know if you have any more questions.
Guest- Guest
Someone on Ebay is selling new sending units for $60. They look correct.
What George sells (I think) are new sending units for A-body Mopar cars modified to work for an A-100.
Gates makes the fuel filler elbow. Can't remember the P/N off hand.
What George sells (I think) are new sending units for A-body Mopar cars modified to work for an A-100.
Gates makes the fuel filler elbow. Can't remember the P/N off hand.
oo3- Number of posts : 290
Location : new orleans
Registration date : 2008-06-01
i take it because of length of sender unit and tank to back body you have to drop the tank? - i was hoping to do a low dough fix for now - but if i have to drop tank i would rather do it right once - of course now is not a good time for that as i need to get a regular job first - oo3
oo3- Number of posts : 290
Location : new orleans
Registration date : 2008-06-01
itruns - did you put on the ground strap yet and did you see a difference in gauge reading- i clipped a test lead from gas line to sending plate - it seemed to drop just a bit - but i can only put in a quarter tank so maybe with a whole tank the difference might be more? oo3
itruns- Number of posts : 1605
Location : Chicago, IL
Registration date : 2008-07-03
Regretfully no, I haven't gotten the strap yet.
I think the 42 year gauge was a little lazy from not being used for a number of years. The gauge is now going up to the 'F' line, but I still have about 6 gallons left (tank holds 22 gallons I believe) when it gets to the 'E' line. By putting the strap on (that didn't sound right), it may show a little more fuel in there.
Make sure the you're grounding the tube to a good ground on the body.
Have you done anything with the small leak?
Hope the job situation is going better.
- Larry
I think the 42 year gauge was a little lazy from not being used for a number of years. The gauge is now going up to the 'F' line, but I still have about 6 gallons left (tank holds 22 gallons I believe) when it gets to the 'E' line. By putting the strap on (that didn't sound right), it may show a little more fuel in there.
Make sure the you're grounding the tube to a good ground on the body.
Have you done anything with the small leak?
Hope the job situation is going better.
- Larry
donivan65- Governor
- Number of posts : 12246
Location : San Diego, California
Registration date : 2008-05-12
Is the Current limiter good? Those gauges are made to run on 6 volts from the current limiter and when it goes bad, the gauge won't read right.
itruns- Number of posts : 1605
Location : Chicago, IL
Registration date : 2008-07-03
Just wondering, do you think a small capacitor wired in there might help?
donivan65- Governor
- Number of posts : 12246
Location : San Diego, California
Registration date : 2008-05-12
What seems to be the problem,,,,,,the circuit goes from the current limiter to the fuel gauge, to the sending unit then to ground. What is the sending unit,,,,,a 0 to 30 ohm unit? You need to test each section,,,,,
itruns- Number of posts : 1605
Location : Chicago, IL
Registration date : 2008-07-03
The limiter is the points style, so the voltage is constantly varying (that's why I used the analog meter). There are now limiters that are electronic with steady voltage. Just wondering if it might help a 42 year old gauge.
donivan65- Governor
- Number of posts : 12246
Location : San Diego, California
Registration date : 2008-05-12
The Gauge probably needs a 0 to 30 ohm signal from the fuel sender to work,,,,,and if it gets something different, the gauge won't read right. So if you get a bad connection, that messes up the signal. Another thing is even if your fuel sending unit is good,,,,the floats leak and gas gets into them and it gets too heavy to float up, so it never reads FULL.
They make variable resistance testers that let you simulate the fuel sender so you can test the gauge. My way is to go to Radio Shack, get a 15 ohm resistor, and hook it to the wire off the sending unit and to to ground. 15 ohms, (IF your system is a 0-30 ohm one) is right in the middle,,,,,which is the 1/2 full mark on your gauge. Put it in and see if the gauge reads 1/2,,,,,,that tests the current limiter, wiring and gauge. If the gauge reads 1/2,,,,the problem is the sender, float or ground.
They make variable resistance testers that let you simulate the fuel sender so you can test the gauge. My way is to go to Radio Shack, get a 15 ohm resistor, and hook it to the wire off the sending unit and to to ground. 15 ohms, (IF your system is a 0-30 ohm one) is right in the middle,,,,,which is the 1/2 full mark on your gauge. Put it in and see if the gauge reads 1/2,,,,,,that tests the current limiter, wiring and gauge. If the gauge reads 1/2,,,,the problem is the sender, float or ground.
itruns- Number of posts : 1605
Location : Chicago, IL
Registration date : 2008-07-03
Thanks for the cool tip Don. Cheap testing method, gotta love it.
The Dodge As are: empty = 73 ohms, full = 8 to 12 ohms. My new sending unit shows 11 ohms. So to do the 1/2 full test, I take it we need approx. 21.5 ohms. Will a 20 + a 2 in series work?
The Dodge As are: empty = 73 ohms, full = 8 to 12 ohms. My new sending unit shows 11 ohms. So to do the 1/2 full test, I take it we need approx. 21.5 ohms. Will a 20 + a 2 in series work?
oo3- Number of posts : 290
Location : new orleans
Registration date : 2008-06-01
no fix yet - out of town visitors this last week - and if i have to drop tank to take sender out i should just wait until i can replace with a new one - i really did want to just solder it but dont want to drop tank twice to do the right thing later - if your ohms range is from app 8/12 to 73 wouldnt you minus instead of add - or am i missing something - your range would be app 60 and then a 30 ohm resistor would be used - (?) - oo3
itruns- Number of posts : 1605
Location : Chicago, IL
Registration date : 2008-07-03
Oops again. Sorry, my bad.
73 - 10 = 63 ohm range. 63 / 2 = 31.5. 31.5 + 10 (base) = 41.5 ohms. It might still be off...
73 - 10 = 63 ohm range. 63 / 2 = 31.5. 31.5 + 10 (base) = 41.5 ohms. It might still be off...
donivan65- Governor
- Number of posts : 12246
Location : San Diego, California
Registration date : 2008-05-12
You are getting a little more complicated than it really is,,,,If you say the senders working range is 73 to 10 ohms, that means when the float is up at the FULL position, the sender resistance is 73 ohms ,,,when it drops down to EMPTY,,,,,,10 ohms. Or it could also be just the opposite,,,,,Unless you know the specs for Full and Empty,,,then lets just go for the middle,,,,,1/2 a tank,,,it does not change. So lets see,,, there are 63 gallons between the high and low readings, so 1/2 of that is about 32 , and we are really talking Ohms,,,,and you don't have to be exact,,,,But if you put 30 ohms between the sending unit wire and ground,,,,the gauge should read 1/2 if everything forward is working right,,,,If you ground the sender wire temporarily,,,,that is the low number,,,,see what the gauge does,,,,,Empty or Full-- that will tell you which number is which. Then with the sending unit wire off,,,,,turn the key on,,,,thats the high number,,,,,,see what the gauge says. When the gauge lies to you,,,,,you can just try and isolate where the problem is,,,,and that sender wire is a good place to start,,,,,,you can eliminate the wiring, gauge and current limiter if it passes the test. Then you start looking at the sender,,,,,
donivan65- Governor
- Number of posts : 12246
Location : San Diego, California
Registration date : 2008-05-12
Here is the inside of a sending unit,,,,,the magic part is that curved resistance strip that the contact on the float arm rides up and down to send an OHM signal to the gauge that causes the needle to move,,,,,You say the specs are 10 to 73 Ohms,,,,My van is 0 to 30,,,,2nd Gen Chevys are 0 to 90,,,,,same principle,,,,, a Big number then a Little one to make the gauge needle go from Empty to Full,,,,
itruns- Number of posts : 1605
Location : Chicago, IL
Registration date : 2008-07-03
Thanks for the input Don. I do tend to over-think things sometimes. But Lord knows I wish I hadn't under-thought a few other things in my life as well.
It's kind of starting to annoy me that I have a quarter tank left and the gauge shows 'E'. I think the grounding wire should help a little. If it really gets the best of me, I could always drop the tank again and bend the float wire down a little bit, but I'm probably too anal to let it get to that.
Right now I'm happy I can park the van in my home's the garage and not have my wife complain (rightfully so) that she smells gasoline. I also don't have to worry about running out of gas anymore.
It's kind of starting to annoy me that I have a quarter tank left and the gauge shows 'E'. I think the grounding wire should help a little. If it really gets the best of me, I could always drop the tank again and bend the float wire down a little bit, but I'm probably too anal to let it get to that.
Right now I'm happy I can park the van in my home's the garage and not have my wife complain (rightfully so) that she smells gasoline. I also don't have to worry about running out of gas anymore.
donivan65- Governor
- Number of posts : 12246
Location : San Diego, California
Registration date : 2008-05-12
Empty with a 1/4 tank sounds like the float is saturated and sinking to the ground while the tank still has fuel in it. If it is reading Empty, that means it got too much ground. take an ohm meter and measure what the sending unit says when your gauge reads Empty. 10 ohms means the float arm is at its bottom of its travel. You just want to try and isolate what end the problem might be at. Was it always this way???? I do go out to your area each time I come to Chicago, to my cousins in Lombard,,,,St Charles Road.....
itruns- Number of posts : 1605
Location : Chicago, IL
Registration date : 2008-07-03
I put the sending unit (new) with the plastic bottle float in 2 months ago. I don't know when the gauge last functioned prior to that. The gauge goes past 'F' when grounded. If it was opposite I could probably put a resistor in line to fake out the gauge a little. If the limiter isn't putting out enough voltage I assume the gauge would show a little lower, thus my thought on the capacitor. I don't have a grounding strap yet, so that could be a small issue as well.
Rt. 83 and St. Charles Road is about 15-20 minutes from my shop (where I've been known to spend way too much time) which is near Rt. 72 (Higgins/Oakton) and Rt. 83. Give me a shout the next time you're coming to this side of the Mississippi. I'd be thrilled to see that red 1st Generation of yours and swap notes.
Century Glass - 1315 Howard Elk Grove Village, IL 60007 - (847) 758-9800 - Larry
Rt. 83 and St. Charles Road is about 15-20 minutes from my shop (where I've been known to spend way too much time) which is near Rt. 72 (Higgins/Oakton) and Rt. 83. Give me a shout the next time you're coming to this side of the Mississippi. I'd be thrilled to see that red 1st Generation of yours and swap notes.
Century Glass - 1315 Howard Elk Grove Village, IL 60007 - (847) 758-9800 - Larry
donivan65- Governor
- Number of posts : 12246
Location : San Diego, California
Registration date : 2008-05-12
The gauge is set for 10 ohms, grounding it is 0 ohms, so that just hurts the gauge if you ground it too long. You will probably see me on my 72 Honda Scrambler when I come to Chicago. I will bring it on my rear bumper of Chevy TransVan. I have to watch my 65 24 hours a day if I bring it to the South Side of Chicago.
itruns- Number of posts : 1605
Location : Chicago, IL
Registration date : 2008-07-03
When I was testing things out several months ago, I just grounded the gauge for a few seconds so it should be OK.
I hear you on the South (West or North for that matter) Side thing. It sucks when they steal your pager while you're holding a 80 x 130 sheet of plate. I could bring my Scooby by your cousin's place as long as it's not raining.
I hear you on the South (West or North for that matter) Side thing. It sucks when they steal your pager while you're holding a 80 x 130 sheet of plate. I could bring my Scooby by your cousin's place as long as it's not raining.
oo3- Number of posts : 290
Location : new orleans
Registration date : 2008-06-01
just to check the grounding strap you could use a clip lead like i did or a piece of wire and a couple clamps or ? - just to temp and see if it makes a difference - takes a minute or so to see change in reading - oo3
itruns- Number of posts : 1605
Location : Chicago, IL
Registration date : 2008-07-03
Filled the gas tank on the way home today. Pulled in on E. Expected to have 5 or 6 gals as reserve so with a 19 gallon tank, should have only taken 14 gallons. It took 16 gallons. Yeah Baby! Maybe the new electronic VR made a difference? Anyways, it now goes up to the Full mark and has 3 gallons in reserve when it hits 'E'.
