Hi to all, I have a 52 Ford f1 with a new gas sending unit that malfunctions when its tight enough to stop fumes from escaping, basically if I loosen the screws a bit then I start getting gas fumes in my cab, the issue is that when its tight enough then my sending unit gives me full tank or starts malfunctioning, I loosen the bolts a bit an it goes back to normal. Have any of you ran into this? I have good ground to the sending unit, the tank is bolted to the cab so its also grounded, so what causes something like this? Thank you all in advance.
Should not be effected by fumes escaping , movin the screws is causing a better ground circuit . Run yourself a new clean ground to one of the sending unit screws from the cab structure , and clean the cab ground to frame or motor and all will be well .
ok I can give this a try, all the wiring is new, to sending unit and ground, but the ground is a small tab welded to the unit, the ground is going to my cab, but the fumes dont cause the issue its being too tight, its weird
I'm thinking that when you crank down on the screws you are distorting the body of the sender enough that it binds up the works just a tad. The fix might be making a steel ring that goes on top of the sender so it will spread the pull of the screws more evenly all around the sender's body.
Mr48chev is right on here I think. Maybe when you crank it down there is just enough flex in the whole unit to make the the rheostat arm lose contact with the pad (loose terminology). Happend to me once. Drove me about halfway to drinking trying to figure it out. Sounds like, as suggested, you need something to spread the torque on the bolt heads. Also, maybe look at the contacts on the rheostat and give the brass arm a little extra bent to make sure the contact isn't so easily lost. Keep us up to date.
you guys might be up to something here, but the unit has these bumps on top that would no allow something to go on top. I did notice that on other units the material where the bolts go is much thicker, mine is the thin sheet metal like material, the only way to find out is if I try the much thicker material units
Sounds like you might have it handled.......just wanted to say that is a beautiful truck! I also have a '52 F-1, of a similar shade of blue.
Check where the gauge wire passes thru the mounting plate. Maybe the insulator is cracked or something, causing the connection to ground out when tightened.
I'm in agreement with Mr48chev..along those lines possibly the sending arm/float is just too long enough that even the slightest tightening/drawing in of the sending unit is causing interference.
Will try a few of these ideas next weekend and let you guys know. My last resort will be to get a different unit.
I'd Disconnect the Battery when fooling around with that sending unit and it wires. Ya don't need ant sparkies ruin'n that nice ride and your Day.
That truck IS the cat's ass! Makes me want to change MY F-1's '50 front sheet metal back to the '52! Hope you find that bug...
So I tried a few things, double cork gasket but did not work, I checked the gasket that prevents the sending unit from shorting and looks good, I did order rubber gaskets and it did help, but I still have to play with the tightness of screws so my gauge does not go crazy, but the fumes are gone, but if tightened too much it still goes bad, I also added special sealant or rtv like that can handle gas and that may have helped with fumes, I also added liquid teflon on the screws….. but if tightened too much I still get gauge malfunction. I ordered a new sending unit from cpp but its the wrong bolt pattern but I wish it worked, the plate where you bolt it from is so much thicker. will post again if I get it completely fixed. As of now some bolts can be tightened about 1/4 more. Thanks for the complements on the truck.
https://www.tanksinc.com/index.cfm/page/ptype=product/product_id=758/mode=prod/prd758.htm https://www.tanksinc.com/index.cfm/...ct_id=759/category_id=-1/mode=prod/prd759.htm I used this type on my Deuce tank. The little O rings thread onto the screws. The gasket is quite thick. It still sounds like your sender deforms it's shape as it tightens.
The Jalopy Journal
