Topic: '35 Ford Fuel Gauge


1935ford    -- 01-17-2012 @ 12:19 PM
  Bought my '35 Sedan in July of '11 and interested in getting the original fuel gauge operating (ran out once!). Would appreciate repair advice and explanation of principle of operation. Thanks.


jims33    -- 01-17-2012 @ 1:55 PM
  I would be interested in hearing what is said about this too. I've had a 33 sedan for a long time and never really got my gas gauge to work good either. I do understand the principle - but getting it to actually tell you how much gas is in the tank is another thing. The u-shaped glass tube in the gauge is filled with that red liquid so it reads empty with the line disconnected. The other end of the tube is open to the air. The line goes to the sender which has a tube in it running to the bottom of the tank. The weight of the gas would compress the air in the tube, transferring the pressure to the red liquid which is supposed to raise up in accordance with the amount of gas. Great idea- no electricty, no moving parts. I suppose the trouble is you always end up with little leaks, either in the connections on the line or maybe rust holes in the tube inside the tank. My gauge moves some (sometimes), but mostly I just look in the tank and shake the car. I've run out of gas a lot of times!
Jim S.


deuce_roadster    -- 01-17-2012 @ 5:19 PM
  For that to work the unit in the gas tank has to be in good shape. If it is gunked up it wont work. There are 3 "bubble catching chabmers" at different levels and they transmit the pressure into a common line that connects to the small line that runs to your dash gauge. Actually the one on the bottom is the only real chamber, the other 2 are like bowls that catch the bubbles in the gas. I have these boiled out and then I solder up the cracks on the bowl shaped parts. If the unit is fixed like this and the small line up to the dash is new, and the fittings are tight it should work. I have fixed lots of these, you can do it too!


drkbp    -- 01-17-2012 @ 6:47 PM
  Hello 1935ford,

I would suggest that you put a new copper air line kit that is available from the sending unit to the dash. The kit will have the red fluid, copper pipe and new fittings. What I never got in a kit was how to do it.
So here we go:
1. Be sure the sending unit in the tank is clean and not gooked up. Unit on mine has a vent on it, clear it and attach the new small copper tube to it and close the hatch. I have a Cabriolet so there is a hatch over the gas tank sending unit under the rumble seat. I am not sure how you access the tank on a sedan but there has to be a hatch there. It's not real fun on a Cabriolet to get to the hatch but I prop the lid when I do this and it's not too bad.
2. Run the fresh copper tube along the frame up to the dash and curl up some slack under the dash. The length doesn't change anything but don't cut it off short.
3. Clean the dash gage out and be sure it is clear before you put the red fluid in it. My gage is a double, Oil and Gas. Some are just gas but it doesn't matter as the routine is the same.
4. Blow out the new small copper line to the tank sending unit. I drain the tank so it is all clear.
5. Be sure the gage does not leak the red fluid. If OK then fill the gage from its top with the air line not hooked up until the red reads empty. That's all you put in.
6. Attach the copper at the gage and put the gage back in the dash.
Put a couple of gallons of gas in the tank and you should see the gage start to climb just a little. There will be enough fluid in the gage for it to read the tank all the way full. If it holds the reading, fill it up. The tank sending unit recharges the air traps as you drive. I drive mine all year but it does not seem to leak down at all. Pretty slick setup really.

If you are using the old copper small tube, be sure it is clear of any fluid, gas, crud, etc by hooking up air to blow it out. That will mess up the gage if you have anything but air in the very small copper tube. Works good if you do it right.

Let us know how you fair. Ken in Texas


jims33    -- 01-18-2012 @ 6:06 AM
  Thanks guys, now I'm interested in getting mine to work too. I remember putting in a new line and fluid many years ago, but I don't think I looked much at the sender unit. I should order a new line kit and start all over. Maybe by spring there will be a couple more old Fords running around with working gas gauges!
Jim S.


1932BB    -- 01-18-2012 @ 10:12 AM
  I made a good one (that works occasionally) from three donors. All had a rod that was in the reservoir connected to the glass tube, and appear to be brass. All rods were not the same diameter. Possibly a calibration tool. If inserted, it would make the guage more responsive i suppose.

This message was edited by 1932BB on 1-18-12 @ 11:03 AM


1935ford    -- 01-18-2012 @ 6:10 PM
  Thanks deuce_roadster and drkbp for your info and advice. I'm sure it will prove to be very useful.
And, jims33: Good luck with yours! - R.J.


1935ford    -- 01-18-2012 @ 6:11 PM
  Thanks deuce_roadster and drkbp for your info and advice. I'm sure it will prove to be very useful.
And, jims33: Good luck with yours! - R.J.


40 Coupe    -- 01-19-2012 @ 4:34 AM
  The biggest sticking point is probably the dash gauge. The hex shaped tank in the rear of the gauge is a storage tank for the red indicating fluid (this is where the fluid is added) that is seen in the glass tube in the front of the gauge. The very small tube between the hex tank and the glass tube must be open so the fluid can move back and forth between the glass and the tank. If the tube is blocked it sometimes can be opened with a small piece of wire. It can be removed from the tank by unsoldering or breaking at the tank and resoldered after the tube is opened. There are some replacement tank, tube and glass assemblies around so most gauges can be repaired.


Dave D    -- 01-24-2012 @ 11:10 PM
  I have complete instructions. You can view them here.

http://photobucket.com/FordFuelGaugeRepair


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