SkyTrak 3606 Service Manual - Manual (Page 159)

Perkins Engine
8A-13
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.
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 (item 21,
Fig. 8A–7) and the fuel sender cover (22) to the fuel
tank. Secure with four #10-24 x 3/4" pan-head
screws (24), and four #10 lockwashers (23).
2. Coat threads with Teflon® (38) and install the black
MI #6P square-head plug (20), the #6-6P hose barb
coupling (19), the #5-6P 90° hose barb elbow (16)
and both #10-6P 90° hose barb elbows (17).
3. Replace the fuel tank in the cab mount subframe.
Attach the fuel level gauge wire to the #10-24 x 5/8"
pan-head screw (25), slide a #10 lockwasher (23)
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 4 Cab, Covers and Mirrors to replace the
other fuel system components and the cab.
8A.7.3 Fuel Level Sender and Gauge
The fuel level sender and gauge assembly is described in
Section 10 Electrical System.
8A.7.4 Fuel Lift Pump Testing
To test the diaphragm, remove the fuel inlet line from the
lift pump (Fig. 8A–8). Block the fuel inlet with a finger and
operate the priming lever. A properly operating pump will
provide suction that will remain until the finger is removed
from the inlet. To test pump performance, disconnect the
outlet line from the fuel lift pump to the fuel filter and
rotate the engine; a spurt of fuel should occur for every
two engine revolutions.
Figure 8A–8. Typical fuel lift pump.
To Check Pressure with Pump in Position:
1. Fit a 0 to 10 psi (0 to 0,69 bar) pressure gauge to the
pump outlet. Ensure that there are no leaks at the
connections between the gauge and the pump.
2. Crank the engine for 10 seconds and note the
maximum gauge pressure. If the maximum gauge
pressure is less than 4.5 psi (0,31 kgf/cm
2 or
31 kN/m
2
), replace the pump.
3. Stop cranking the engine and time how long it takes
for the pressure to drop to half the maximum
pressure noted. If less than 30 seconds elapses,
replace the pump.
A. Fuel Lift Pump Removal
1. Clean debris from around the lift pump.
2. Disconnect the fuel lines.
3. Remove the capscrews, gasket, and fuel lift pump.
B. Cleaning and Drying
Clean the exterior of the pump with mineral spirits and
blow dry with compressed air.
Note: Parts replacement is not practical. The fuel lift
pump is serviced as an entire assembly.
C. Fuel Lift Pump Installation
1. Clean the mounting surface on the cylinder block.
2. Install the fuel lift pump with a new gasket. Install and
torque the capscrews to 18 lb/ft (24 Nm).
3. Connect the fuel lines.
OA0332
Fuel lift pump
Priming lever
Model 3606 • Origin 10/99