Bob's Studebaker Resource Website

Studebaker Avanti Gas Tank

    • Top drain by filler can be plumbed for the return line
    • Hole in body underneath has elbow for connection to chassis fuel line. Hole is also a drain for fuel that may get trapped due to loose or torn filler hose connector or overflow hose.
    • Overflow is routed to passenger side wheel well.
    • NOTE Rubber lines MUST be replaced with new alcohol resistant "nitrile" rubber compound or they will deteriorate and fail ( if they haven't already crumbled from age)...
    • Panel behind rear seat had 24 screws around the perimeter. The panel is fitted to the opening after applying a sealing caulk around the flange. The caulking is there to prevent gas or exhaust fumes from entering the passenger cabin

    • You must remove the rear panel and pull the tank forward to service the fuel gauge sending unit.Gas tank sender screws and copper washers ( Not the sender) SENDERS
      1963 to (all cars that used the SW gauges)
      (be sure and disconnect the battery) Replacement part from NAPA.
      Fuel Sending unit, Stewart Warner PN-701-1574 (385C-F1)
      33 Ohms full / 240 Ohms Empty. the sending unit must match the Ohms of the gage.
      Chuck Rone Jan 2009

      G145331, screw to tank, No.10 x 5/8" Not listed on SASCO's online catalog.
      (SASCO does list the Washers)
      187763 Washer, special
      ($1.00 ea.)

      A couple of things to check / reminders (BTW there is already a pretty detailed thread in this group re: sending units)...
      The older sending units are little more than resistance wire with a sliding contact to pick up the voltage. With time (as with any sliding contact / various metals) the metal corrodes (moisture in the fuel/tank) and the contact point on the pick-up wears down causing erratic or no readings.
      A few folks have had luck removing and cleaning the contact and resistance wire with electrical contact cleaner (Radio Shack or a better auto parts store) but the time involved in removal / replacement of the sending unit makes this a spotty proposition at best (especially since the brand new sending unit is less than $30 at my local Stewart Warner distributor (don't know where you live but the S-W website lists distributors in most states).

      Watch out with the sending units...many vendors still have stock on the older res. wire type and will happily sell them to you without mentioning that Stewart-Warner's newest designs are all of the "thick film" variety (no more wire / copper contact to corrode / go bad) that are far more durable especially with ethonol containing fuels! Also, quite often the bad reading is caused by a poor ground connection to the sending unit itself (often the action of removing / replacing the sending unit "cleans" the ground path / connection when the unit is tightened down leading to the conclusion that the new sender solved the problem when, in fact, the simple act of scraping the ring terminal faces and screw to mounting plate or tank threads is what REALLY solved the problem).

      When re-installing the sender folks often coat (intentionally or not) the screw / tank threads with gasket sealer in an effort to "make sure the sending unit is sealed to fume / fuel leaks" thereby creating an insulator in the ground path. Make sure the little copper washers for the mounting screws are all present and accounted for (new ones only...they are a "crush" washer!).
      THEY, in conjunction with the sender to tank gasket are what are supposed to seal AND make a solid electrical connection for the gage! You are dealing with relatively little resistance / current here so any addl. resistance will cause big problems! When I first installed the new sender I was getting a jumpy reading until I tightened 2 or 3 of the mounting screws another 1/2 turn or so! Finally, I had an issue with the rubber (neoprene?) gasket supplied by S-W in that, after a few months, is swelled up and became very soft to the point of allowing leakage!! S-W claims it is ethonol compatible (up to the 10% blend in most gas) but a replacement with the older style paper gasket is still dry after 5+ years!
      Hope it helps!!
      Tom Gorr / RQB 3449 May 2009