Re: Fuel Gauge Woes....

Posted by Owen_Dyneto On 2010/3/26 17:45:59

The current problem you have is almost 100% with the sending unit in the tank and not with the dash gauge but check it out as per HH56's info. You need to drop the tank to get the sending unit out, but that's pretty easy too unless it happens to be full with 25 gallons of gas, it's held in place by just a couple of cross-wired bolts - no straps. Typically you either fix the rheostat yourself if your handy, or send it away to one of the many folks who repair these. I don't know if your tank has been cleaned and coated but if not, it's a bit of an issue because of the 3 internal baffles which form 6 individual compartments to prevent sloshing. The individual compartments are connected by small metallic screens at openings in the base of the baffles, and sloshing a coating sealer in the tank often closes them off, leaving you with what might be a 4 gallon gas tank. Most tank rebuilders of these cut the top out of the tank to service the internals.

The earlier problem you had, constantly low readings, was almost certainly because all the years of use had removed the shellac from the cork float. Use of shellac today is questionable as the ethanol in gasoline is a good shellac solvent. There are other coatings you can use to coat the shellac, and some folks just replace the cork float with a brass one from a more modern vehicle. I did mine about 15 years ago and used shellac to coat the cork and it's still OK today despite the modern gasoline.

The 1934 service letters which are on this website have some information about positioning the sending unit float arm. I believe your gas gauge is a Waltham dash unit and S-W sender. It's of the "instant read" type, not the thermostaticly dampened type.