HOSE AS 3816651 - Caterpillar

CLOSE inlet and outlet ball valves.
Fully CLOSE inlet ball valve by moving handle (3a) away from the inlet pipe, as shown.
Fully CLOSE outlet ball valve by moving handle (20a) away from the outlet pipe, as shown.
Illustration 33 g02722607
Check both differential pressure gauge (5) follower needles for readings above 172 kPa (25 psi) to help identify which filter is restricted.Note: If differential gauge readings are normal, check for high water accumulation in sight glass (8). Use manual water drain valve (11) to remove water from coalescer vessel (7). Resume refueling operation.
If differential pressure gauges (5) indicate restricted filters, refer to the Maintenance Section in this manual for filter element replacement procedures.
Illustration 34 g02722655
(18) Typical Slug Valve Shown in SET Position
Once all restrictions are corrected, reset slug valve (18) by moving lever from TRIPPED position to SET position.Note: If slug valve (18) will not reset, or immediately closes again, refer to the Troubleshooting Section in this manual, or contact your local Cat dealer for assistance.
Slug valve is factory set to 172 kPa (25 psi) differential pressure. Do NOT adjust factory setting. Changing the setting can result in improper fuel filtration and damage to the bulk fuel filtration system components.
Note: To ensure fuel quality, have fuel cleanliness tested on a regular basis. For more information on fuel quality testing, refer to the latest version of SEBU6250 Cat Machine Fluids Recommendations.Service Parts
Illustration 35 g02722674
(24) Typical Pre-filter Element (25) Typical Coalescer Element (26) Typical Separator Canister
Table 3
Service Parts    
Item     Part No     Description     Qty    
24     284-0435     Pre-filter Element Kit (1)     1    
25     284-0423     Coalescer Element Kit (2)     1    
26     284-0426     Separator Canister (3)     3    
    307-0655     Optional Heater (120 VAC)     1    
    307-2569     Optional Heater (240 VAC)     1    Reference (1) Includes one pre-filter element and one pre-filter vessel o-ring seal. (2) Includes three coalescer elements and one coalescer vessel o-ring seal. (3) Separator canisters do not require replacement unless damaged or corroded.Troubleshooting
Table 4
Troubleshooting Chart    
Problem     Possible Cause     Possible Solution    
No fuel flow     Inlet or outlet valve is closed     Open inlet/outlet valve    
Fuel hose is kinked Straighten hose and/or provide larger hose    
Automatic slug valve shutdown Check differential pressure gauge follower needles for differential pressure reading. greater than
172 kPa (25 psi). The slug valve will close if filters are restricted. Change filter elements and reset slug valve.    
Check sight glass for high water accumulation. Wait until system purges water or drain water manually. Reset slug valve.
Differential gauge reading greater than
69 kPa (10 psi) at start-up     Air in the system     Open vent valve at top of pre-filter vessel to release trapped air.    
Differential gauge reading greater than
172 kPa (25 psi)     Filter elements are restricted     Replace filter elements and clean vessels. Reset slug valve if necessary.    Maintenance Record
Replace filters at least every six months. Clean debris from vessels annually, or as needed