Dodge RamCharger Central banner
1 - 8 of 8 Posts

·
Registered
Joined
·
619 Posts
Discussion Starter · #1 ·
i have a 78 pw, long bed with the 20 gallon(?) side tank. i need to put a new sending unit in it as well as a new seal. was wondering if anyone could give me some tips for good results. also, does dodge sell new sending units for a 78, or should i go to an auto parts store? thanks for any help.
 

·
Registered
Joined
·
2,818 Posts
call teh dealer and see. napa or someplace like that should have one. to help drop it have a floorjack so you can drop it easily. i have a 77 PW with the 20 gallon tank so i can help as much as possible
 

·
Registered
Joined
·
619 Posts
Discussion Starter · #4 ·
would i be able to find a sending unit at any old parts store like carquest or kragen? also, i cant seem to find a seal, so would making a new one out of gasket material (cork perhaps?) be an acceptable replacement?
 

·
Moderator
Joined
·
7,995 Posts
would i be able to find a sending unit at any old parts store like carquest or kragen?
If you did find one at the local store it would be universal...it may or may not fit the tank...it may or may not have the correct resistence values for your dash gauge to read correctly.

also, i cant seem to find a seal, so would making a new one out of gasket material (cork perhaps?) be an acceptable replacement?
NO, if you make the gasket out of the incorrect material or dont get it made in the proper shape, you will have leaks and a possible fire hazard. The gas tank is not an area to cut corners on. :)

The gasket should still be available from Mopar under part# 3730757...($5 or so)call your local dealer..if he cant get one then let me know and I will tell you where to check at other dealers acroos your state and the nation. Also you may get a new seal with the replacement sending unit. :)
 

·
Registered
Joined
·
10,862 Posts
Run the tank DRY if you can!! Thats about all I can tell you, sorry. ;D
 

·
Registered
Joined
·
537 Posts
Here is what I have done and it worked for me. Purchase a new sending unit. Carry a gas can with a few gallons of gas in it. Drive the truck until it is empty, if you get stuck away from home, you have the extra fuel with you. Drop the tank. Attach the new unit to the wire(s) if the unit has only one wire, you will need to ground the sensor to the body/frame somewhere. I suggest vise grips. Verify the operation by moving the float through its range and read the gauge readings. Do this BEFORE putting it into the tank and remounting the tank.
 

·
Premium Member
Joined
·
8,998 Posts
I agree with 440 ramcharger, but I have one addition.

If you have a way to get gas out of the tank (siphon or small pump, I would set the tank on level ground, and use some extra wire to extend the connections to the truck. Now, with the sending unit in the tank, and the tank on the ground, fill it slowly, and note when the gage reads empty, 1/4, 1/2, 3/4, and full. if you fill it 1 gal at a time, you will know EXACTLY how much fuel you have at the various points. If you want to adjust it, you can do so at this point, but if it is already in the truck, it's kinda hard to adjust.

I did this when I put a 35 gal tank in my truck, and I adjusted the float so that when it reads empty, I know I have exactly 7 gals left. I also know that when it reads above full, I have 7 gals before it gets down to the full mark. I was more intertested in knowing what it has in it at the diff levels because I made the unit for my truck by using the old pickup tube & filter assembly and grafting on a new swing arm & float assembly.

It's not perfect, but it works for me, and I know exactly how much fuel I have at any point within a gal or two, depending on vehicle loading.

F - 34-35 gals
3/4 - 27-28 gals
1/2 - 20-22 gals
1/4 - 15-16 gals
E - 7-8 gals
 
1 - 8 of 8 Posts
Top