Attention: TDR Forum Junkies I was traveling this weekend and stopped at a Love's truck stop to fill up. As I am topping off the tank I am watching the level of the fuel in the neck and it seems to be decreasing much faster than it usually does. I did leave the truck running because I had my son in his car seat, so I thought that might be the reason, but thought that it was going down awfully fast even for that. I squeeze the trigger one more time to get another splash of fuel in there and I notice fuel pouring all over the place underneath the truck. I hurriedly replaced the fuel nozzle at the pump (while cursing and causing a scene for the people at the next pump) and started looking around to see where it was coming from. I look through my wheel well (no liners, still haven't added them) and I see a steady stream of fuel pouring straight up out of the top of my fuel sending unit! It was probably about 2" - 3" above the fuel sending unit and just running down the sides of the tank. I pulled off the island and parked and it had stopped by that time.
What I found out to be the culprit is shown in this picture here (borrowed from Spooled-Up's readers rigs gallery).
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If you look at the sending unit, to the left of where the electrical connector is (center), you will notice a small rubber cap with a hose clamp on it. It seems that the top of this rubber cap vaporized (broke and fell off) and because I topped the tank off, and the extra room in the tank is higher than the sending unit, allowed the fuel to pour out of the fitting, until the level reached that of the fitting.
I wanted to post this more as a warning to those of you who do not have the in-tank style lift pump (pre-'05) and who are running the vent kit. After examining the remaining portion of my now useless cap and comparing to a piece of fuel line, my theory is that this cap is not rated for fuel system use. If this is the case the constant fill ups to over the maximum designed capacity of the fuel tank (35 gal for a long bed, actual capacity with vent kit ~42 gal) has allowed this cap to soak in diesel fuel degrading its quality and allowing it to breakdown and crack.
I tried to find another cap but the only caps my parts store carries were rated for vacuum use. So I made my own cap out of a section of 5/16" fuel line and a bolt. I haven't filled up since then but I will make sure to post the results once I do.
So those of you running the vent kit on '03-'04. 5 trucks (or who take the time to top off the tank), if you still have the original sending unit, go out and examine this cap for cracks, tears, or any other defects. Otherwise you may wind up like me and pouring about $3-$5 of fuel somewhere other than your fuel tank.
Jeff
What I found out to be the culprit is shown in this picture here (borrowed from Spooled-Up's readers rigs gallery).
If you look at the sending unit, to the left of where the electrical connector is (center), you will notice a small rubber cap with a hose clamp on it. It seems that the top of this rubber cap vaporized (broke and fell off) and because I topped the tank off, and the extra room in the tank is higher than the sending unit, allowed the fuel to pour out of the fitting, until the level reached that of the fitting.
I wanted to post this more as a warning to those of you who do not have the in-tank style lift pump (pre-'05) and who are running the vent kit. After examining the remaining portion of my now useless cap and comparing to a piece of fuel line, my theory is that this cap is not rated for fuel system use. If this is the case the constant fill ups to over the maximum designed capacity of the fuel tank (35 gal for a long bed, actual capacity with vent kit ~42 gal) has allowed this cap to soak in diesel fuel degrading its quality and allowing it to breakdown and crack.
I tried to find another cap but the only caps my parts store carries were rated for vacuum use. So I made my own cap out of a section of 5/16" fuel line and a bolt. I haven't filled up since then but I will make sure to post the results once I do.
So those of you running the vent kit on '03-'04. 5 trucks (or who take the time to top off the tank), if you still have the original sending unit, go out and examine this cap for cracks, tears, or any other defects. Otherwise you may wind up like me and pouring about $3-$5 of fuel somewhere other than your fuel tank.
Jeff
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