Fuel Level Sender And Gauge; Fuel Lift Pump Testing - JLG sky trak mmv Service Manual

To clean the fuel tank:
1. Have a dry chemical (Class B) fire extinguisher near
the work area.
WARNING:
fuel in an open container due to the possibility
of explosion or fire. Discard the fuel in an
approved manner.
2. Invert and tilt the tank from side to side. Safely drain
any fuel into a suitable container. Dispose of fuel
properly.
3. Clean the fuel tank with a high-pressure washer, or
flush the tank with hot water for five minutes. Invert
the tank, tilt it from side to side, and drain the water.
4. If necessary, add a diesel fuel emulsifying agent to
the tank. Refer to the manufacturer's instructions for
the correct emulsifying agent-to-water mixture ratio.
Refill the tank with water, and agitate the mixture for
10 minutes. Drain the tank completely.
5. Refill the fuel tank with water until it overflows.
Completely flush the tank with water. Empty the tank
and allow it to dry completely.
d. Inspection
1. Inspect the fuel tank thoroughly for any cracks,
slices, leaks or other damage. Replace a leaking or
damaged tank. DO NOT attempt to repair, plug or
patch a leaking or damaged fuel tank. The tank is
manufactured using an injection molding process
and cannot be repaired. If a leak is detected at any
of the grommets on the tank, replace both the
grommet and fitting. Contact JLG Inc.directly at:
Domestic: 1-717-485-5161
International: 1-877-554-5438
2. With the fuel tank removed from the vehicle, plug all
openings except one elbow fitting. Install the elbow
fitting and apply approximately 1 to 1-1/2 psi
(7 to 10 kPa) of air pressure through the elbow.
Check the tank for leaks by applying a soap solution
to the exterior of the tank, or by submerging the tank
in water and looking for bubbles to appear at the
cracked or damaged area.
e. Assembly and Replacement
1. Install the fuel sender with gasket (6) and the fuel
sender cover (5) to the fuel tank (1). Secure with four
#10-24 x 3/4" pan-head screws (2), and #10
lockwashers (4). Do not overtighten.
Model MMV Rev. 12/04
NEVER drain or store
Engine: Cummins 4BTA 3.9
2. Install the 3/8" NPT square head pipe plug (7), the
3/8" barb hose connector (8), the 5/16" P 90° hose
elbow (9) and both 5/8" hose barb elbows (10 and
11) into the fuel tank grommets.
3. Replace the fuel tank (1) in the cab mount subframe.
Attach the fuel level gauge wire to the #10-24 x 5/8"
pan-head screw (3), slide a #10 lockwasher (12)
onto the screw and secure the screw to the fuel tank
at the fuel sender cover.
4. Reconnect the fuel hoses and follow the directions in
Section 3.2.3, c. Cab Installation to replace the other
fuel system components and the cab.
3
12
7
6
8
9
11
8.8.3

Fuel Level Sender and Gauge

The fuel level sender and gauge assembly is described in
Section 10.13.19, Fuel Level Indicator and Fuel Level
Sender .
8.8.4

Fuel Lift Pump Testing

Inspect the camshaft lever and return spring for exces-
sive wear. To test the diaphragm, remove the fuel inlet
line (13) from the fuel lift pump (14). Block the fuel inlet
with a finger and operate the hand plunger (15). A prop-
erly operating pump will provide suction that will remain
until the finger is removed from the inlet.
2
4
5
1
10
MM4560
8.21