Fuel Gauge - Inaccurate Reading

9220audi01

Number:
89-01
August 7, 1989


Group:
20


Fuel System


Applies To:
80/90 All m.y.


Subject:
Inaccurate Fuel Gauge Reading





The following work procedure applies to vehicles equipped with 18 gallon (68 liter) upright fuel tanks.

This circular describes how to remedy a sticking fuel tank sending unit as well as eliminating the clunking noises caused by the fuel tank sending unit float arm when it makes contact with the filler neck vent tube while stopping or when driving over dips and bumps.


WARNING

Do NOT smoke or have anything in area that can ignite fuel.


^ in this example, note the position of the fuel filler vent tube relative to the float arm

Note

This condition can cause the fuel sending unit float arm to hang up on the tip of the vent tube, erroneously causing the fuel gauge to read more than 3/4 full when in actuality the fuel level can be less than 3/4 and even completely empty.





^ this condition will cause one or more of the following:

scraping, rattling or clunking over bumps and during braking





^ remove gas cap from filler neck to relieve any residual pressure in tank

^ remove clips and trunk lining to gain access to the fuel sending unit





^ remove fuel tank sending unit using tool 2012 A





CAUTION

Use extreme care when removing or installing the fuel tank sending unit. Do NOT bend the float arm (arrow) or inaccurate fuel gauge readings could result.





^ locate the filler neck vent tube inside the fuel tank using a flashlight through the sender mounting hole





^ using large slip joint pliers, place top jaw on filler neck vent tube and bottom jaw onto a block of wood as shown

^ squeeze pliers until the end of the filler neck tube is repositioned inward approximately 19 mm (.75 in) (arrow)





CAUTION

Do NOT damage the fuel tank sending unit mounting surface while performing this procedure.





^ reinstall fuel tank sending unit with a new seal (arrow) P/N 113 919 131 A


CAUTION

Part numbers are for reference only. Always check with your Parts Department for latest information.





Note

When the filler neck vent tube is correctly positioned the float arm should be slightly forward of the vent tube (arrow).





^ after reinstalling the fuel tank sending unit, perform a slack tube test to ensure that the fuel and evaporative systems are free of leaks.


Labor Operation Number: 2000710
Suggested Repair Time: 80 t.u.