Fuelpump And Fuellevelsender; Fuel Level Sender (Right Side) And Fuel Pump. Removing And Installing - BMW 5251 Service Manual

.-
err-
. -
Fuel Tank
and
Fuel Pump
FUELPUMP
AND FUELLEVELSENDER
E39 models use a two-lobed fuel tank. Each lobe of the tank
has its own fuel level sending unit. Each sender has a float
connected to a variable resistance wipercontact. To equalize
fuel level between the two tank lobes, a siphon pump is in-
stalled in the left lobe.
When replacing asender or fuel pump, always replace hose
clamps, gasltets and O-rings.
WARNING
-
When removing the fuel level sender or the fuel pump, the
fuel tank should be drained to 1/4 capacity or below as de-
scribed later in this repair group.
NOTE-
The compensating siphon pump maintains the fuel level be-
tween the right and left tank lobes. If fuel level sender resis-
tances are not approximately the same on left and right,
remove the senders and visually inspect the level in each
lobe. If the levels are different, check the siphon pump.
Fuel level sender resistances
Float position l ~ e s t results
(Q
Down
(empty)
150-
70
U p (full) 1401 -415
Fuel level sender (right side)
and
fuel
pump, removing and installing
-
Drain fuel from tank as described later.
-
Disconnect negative cable from battery.
CAUTION-
Prior to disconnecting the battery, read the battery discon-
nection cautions given in 001 General Cautions and
Warnings.
-
To access top of fuel tank, remove rear seat lower cushion by
lifting front edge off catches.