Removed fuel sender unit - found problem and solved it

[Dans 68]

I took out the sender unit (with the tank still in the car) by using a long screwdriver and a hammer. Thanks for the suggestions again.   http://www.dodgecharger.com/forum/index.php/topic,68963.0.html

The problem with the sender unit was that the brass float had a hairline crack in it, was full of fuel and, of course, was then reading empty. I took the float off the sender arm (comes right off) and thought about trying to fix it. After I found replacements on eBay for $8.99 I decided not now (but maybe later).  

I attached two photos of the float and its obvious crack. It just seems to be a flaw in the material.

I also took the time to make sure the resistance amounts at the empty and full sweeps were within specifications. I attached two photos of those also.

I reinstalled the sender unit back in the tank, minus the float so I could drive the car while I wait for the new float. It is a good feeling to be able to figure out and fix a problem. Just makes driving the car that much better (and I did for a few miles after I got it back together).  

Dan

[Dans 68]

I also connected up the fuel sender unit to the fuel gauge to see how it would read at full and empty readings. It seems to be a bit off. As I had the gauges rebuilt (http://www.dodgecharger.com/forum/index.php/topic,67620.0.html) it seems I need to adjust the upper and lower set points on them. When I get the new brass float installed I'll probably take the gauge out of the dash and adjust it to read perfectly (well, at least touch the full and empty lines on the gauge.  )

Dan

Edit: I added the mid-point on the sender unit arm. At least I will know exactly when I'm at half a tank! 

[nh_mopar_fan]

I swear I seem to recall that there is a Ford part that is exactly the same and is readily available at any dealer and is cheaper than the one on ebag.

anyone?

edit: Found it. Ford P/N COAZ-9202-B

Here's a pic of it.

http://www.dallasmustang.com/popup_image.php?type=D&id=1610&title=GAS%20TANK%20SENDING%20UNIT%20FLOAT%2C%201964-1973&area=C

[Dans 68]

Good to know.    I attached the Ford float photo. But as I already ordered the eBay part I'm not going to sweat it. Considering it would probably take me a good hour to find the Ford dealer closest to me, call to see if it is in stock, go to their parts dept, buy the float and return home, the $11.49 I spent on getting the part is well worth it. Now, if I had to get the car fixed asap the Ford dealer would be a great solution. Thanks again for the suggestion.  

Dan

Edit: The description of the Ford float says it is about 2-1/2" long, whereas the Mopar unit is 2". Shouldn't make a difference, but.... The price was $4.95 in 2004 per a Ford Truck forum. Here is a photo of the Ford float packaged (although they can be bought separately).

[471_Magnum]

You're resistance ranges look about right.

Make sure you have a good ground on the sender. Running a redundant ground from the sender straight to the body (rather than just through the fuel line) is a good idea.

Don't get too obsessed with trying to get that gauge to read perfectly. It's pretty much impossible.

[1970Moparmann]

Where did you buy your sending unit?  I have to tackle this within the next week or so. 

Thanks for sharing!

[Dans 68]

Where did you buy your sending unit?....

I think it is the original unit. The part number on it is #2947 691        1609.

Dan

[Nacho-RT74]

You're resistance ranges look about right.

Make sure you have a good ground on the sender. Running a redundant ground from the sender straight to the body (rather than just through the fuel line) is a good idea.

Don't get too obsessed with trying to get that gauge to read perfectly. It's pretty much impossible.

fortunatelly mine is reading PERFECT! from top to bottom, even witha repro sender

[Nacho-RT74]

http://cgi.ebay.com/ebaymotors/MOPAR-Sending-Unit-Fuel-Tank-Brass-Float-Dodge-Plymouth_W0QQitemZ330419747789QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item4cee8d3bcd

but just $2.5 shipping

[Dans 68]

http://cgi.ebay.com/ebaymotors/MOPAR-Sending-Unit-Fuel-Tank-Brass-Float-Dodge-Plymouth_W0QQitemZ330419747789QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item4cee8d3bcd

but just $2.5 shipping

Yes, that is the company I bought mine from.    I'll post a photo of it, next to the original, when it arrives.

Dan

[Nacho-RT74]

just to laugh a little bit

http://cgi.ebay.com/ebaymotors/Mopar-71-72-73-74-Charger-sending-unit-float-NEW_W0QQitemZ170472369925QQcmdZViewItemQQptZOther_Vehicle_Parts?hash=item27b0f1ef05

( I was sure I had seen it cheaper LOL )

[Dans 68]

Good thing I ordered a new replacement float, and didn't try to fix the leak in the old one. Seems our puppy thought it would be a good chew toy. At least now the split in it is visible.  

The new float has been reinstalled, and the gas gauge now works for the first time in years.  

Dan

[Nacho-RT74]

How a floater can get that kind of dent ?

[Dans 68]

How a floater can get that kind of dent ?

...Seems our puppy thought it would be a good chew toy....

The 11 month old one on the right 

Dan