Date:         Thu, 06 Oct 94 20:57:36 CDT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "J. Walker" <JWALKER@ua1vm.ua.edu>
Subject:      fuel sender repair

ok. here's what i got out of the repair manual.
1968-1979 Buses
  Removing and Installing Fuel Tank Sender Unit
  (from Repair Manual Type 2, Second Edition, VW AG)

The sender unit can be removed without taking out the engine, bulkhead
and fuel tank. This is done by cutting a hole in the floor plate which
is then closed afterwards with a plate available as a spare part.

The following parts are required:
   1 ea.  Cover plate (oval) for floor plate.
          <from the parts fiche: no longer available>
   1 ea.  gasket for cover plate
          <from the parts fiche: 411-805-419B gasket>
   4 ea.  screws B 4.2x9.5, DIN 7981, galvanized
          <from the parts fiche: N-013-965-5 tapp. screw>
   -      VW Universal Adhesive
<i looked on the parts fiche for 1968-79 as of 1983; it's frame 67,
items 51, 52, & 53>

**********************************************
*               WARNING                      *
*  DO NOT USE any of the following tools     *
*  to cut the hole or clean edges:           *
*  Gas Torch,  Grinding Disc, Parting Disc.  *
**********************************************

- Disconnect the battery ground cable.

- Remove the spare tire and spare tire cover.

- Measure the center point of the hole:
   - from the left (driver) interior side panel, next to the
       spare tire hole:
       a = 807mm (31.77 in.)
   - from the rearmost edge of the rear hatch opening (the metal 'rim',
       that is next to the rubber gasket for the rear hatch):
       b = 893mm (35.15 in.)
   - See Fig. 1

- Cut hole and remove burrs.
  - radius of hole is:
       r = 40mm (1.57 in.)
  - width of cut is:
       w = 70mm (2.75 in.)
  - See Fig. 2

- Cut into the rib at front and rear edge of hole about 15mm (0.59 in.)
  and hammer rib flat.  Support metal from underneath with a strong
  lever.

- Check that the plate and seat fit properly.  To ensure that the
  plate seals properly, the hole should be lifted slightly around the
  edge.

- Place the cover over the hole, mark off the screw hole positions on
  the floor plate and drill 3mm (1/8 in.) diameter holes for the four
  screws.

- Renew fuel guage sender unit.

- Connect up the battery ground strap and check operation of the
  sender unit.

- Stick seal to plate and secure plate with four taping screws.

Fig. 1 ----------------------------------------------------------------
                     (rear of bus)

                           latch
        ====================----====================
                     :                              |  a = 807mm
                     :                       |-----||      31.77 in.
                     :                       |     ||
                     :                       |spare||  b = 893mm
                     :                       |tire ||      35.15 in.
                     b                       |hole ||
                     :                       |     ||
                     :                       |     ||
                     :                       |     ||
                     :                       |     ||
                     :                       |-----||
                     :                              |
                     x <-------a------------------->|
 forward edge  > . . . . . . . . . . . . . . . . . .
 of engine ledge
 (dropoff to floor of bus)
Fig. 2 ----------------------------------------------------------------
                     (rear of bus)
 raised ribs-> ||     ||     ||     ||     ||    a = 807mm (31.77 in.)
 on engine     ||     ||     ||     ||     ||    r = 40mm (1.57 in.)
 ledge         ||     ||     ||     ||     ||    w = 70mm (2.75 in.)
               ||     || :  /---- › ||     ||                    |
               ||     || w (-r-x<--)------------a--------------->|
               ||     || :  ›-----/ ||     ||
 forward edge  > . . .|| . . ||. . .|| . . ||. . . .
 of engine ledge
 (dropoff to floor of bus)

description of hole: at the measured point x (a from the side, and
b from the rear edge), draw a circle of radius r.  on the front-rear
axis of the circle, truncate the circle to 35mm in front of x and
35mm to the rear of x (so the hole will look like a flattened circle).
the forward edge of the hole will almost be at the dropoff ledge from
the engine compartment to the floor of the middle of the bus.
-----------------------------------------------------------------------
one of the raised ribs on the engine compartment will be just right
(passenger side) of the point x. this is the one that will have to be
cut and flattened.

the picture shows a flat wrecking bar type instrument being held under
the cut rib, while the rib is being flattend with a small tack hammer.
-----------------------------------------------------------------------
the next picture shows the edges of the hole having been curled upward
just a bit (with pliers, i assume. or with one of those 'lip' maker
tools that body shops used to use).
-----------------------------------------------------------------------
comments: even though the cover plate is listed as 'no longer available',
i suppose you could make your own plate. it would just need to have a small
downward lip around the outer edge ... to secure and seal the gasket in
place. the four screw holes were basically laid out 2 per side of the hole,
like so:         /--------›
               /  o      o  ›
              (       x      )   where x is the center-point of the hole
               ›  o      o  /
                 ›--------/

hope it helps.
joel