Diesel Fuel Tank Pick Up Question

[Rick D]

Quick question: I'm calibrating a fuel tank gauge. I want to adjust the depth to allow for the gap from the tank bottom to the pick up. I've never had mine out, so for those that have, any idea what is a common gap? My WAG is about an inch. (Don't you dare ask me what my WAG is... )

 

[RAD]

I'll take a WAG and say 1/2 inch cause an inch is a lot of fuel that would never get sucked up

 

[Ed Schenck]

Would depend upon the tank design. My pickup comes into the top center on the side of the tank. Then it goes straight down to the bottom seam. Then turns and runs along the seam to the lowest corner. It is on the bottom but within one inch of the corner. Does that make any sense?

 

[Steve Dion]

...and most of that 1" is fuel that you would never want sucked up.

Rick:

I replaced my float in my tank with a WEMA unit. When they spec them out they suggest that you keep it 1" off the bottom.

How do you recalibrate the gauge?

 

[Rick D]

Steve, I am adjusting the float rod length so that it reads empty somewhere before an inch or so off the bottom (probably more since I wouldn't want it sucking air anyway). Where this is all coming from is that my 40.5 had a mechanical sight gauge on top of the tank which was a PITA when fueling. After eleven years, I decided to put an electric gauge on the steering console and an electric sending unit on the tank. I did the job and will post photos and discussion next week. However, by following the directions, my new unit reads 1/8 full tank vs. 3/8 full by way of the mechanical one. The mechanical one was installed by the manufacturer of the tank, so I believe it more than the new one. Anyhow, a quarter tank (level, not volume) should be about 4.5 inches which is about what I think I have in there. I am going to stick it to be sure though. So, I want to calibrate it by trial and error to the measured depth. Make sense? So I wanted to check my seat-of-the-pants one-inch deal on the pick up vs. what others have actually seen. Of course, this all assumes that I can get it that close to begin with...

 

[Bob S]

Rich,

I cut an access hole last season to see what was inside. I was surprised how clean it was. The tube was cut at an angle and went right to the bottom.

 

[Bob C]

Just installed new Moeller tanks and had to pull the pick ups out. There about 1" from the bottom but have a screen type bag(filter) that goes to the bottom

 

[JoeWhite]

I guess it is better to have a 1" gap. This will prevent any possible water that may be at the bottom to be succed up an used instead of fuel.

 

[Steve Dion]

This is the unit that I used from WEMA. (SSS)

http://www.wemausa.com/tank-sensors/index.html#Fuel_Water_Tank_Sensors

I replaced the manual gauge with an electric one also. I could not tell if the tank was full or empty when readiing the gauge. It was a direct replacment for the sensor and the wiring was easy once you figure out what the hell was going on.

I normally log my fuel usage with each fill up and do a visual sight on the gauge. It is also not too accurate, but give me a lot better sense of what is going on than the manual one that I could not read.