Improvements for Operation in Cold-Weather Applications on Certain 777G Off-Highway Truck {1273, 1274, 1296}
- Off-Highway Truck/Tractor
- 777G (S/N: GT71-UP; T5A1-UP; TNM1-UP; RDR1-UP; T4Y1-UP)
Introduction
This Service Magazine contains information on how to prevent fuel from gelling in unusually cold-weather applications.
The following changes are adaptable to the products within the listed serial numbers.
Safety Section
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Improper operation, lubrication, maintenance or repair of this product can be dangerous and could result in injury or death. Do not operate or perform any lubrication, maintenance or repair on this product, until you have read and understood the operation, lubrication, maintenance and repair information. |
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| NOTICE |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products. Dispose of all fluids according to local regulations and mandates. |
Required Parts
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| Parts To Install Fuel Heater | |||
|---|---|---|---|
| 478-5442 Fuel Heater Gp | |||
| Item | Qty | Part Number | Part Name |
| 1 | 1 | Plate As | |
| 2 | 8 | Hard Washer | |
| 3 | 4 | Bolt | |
| 4 | 1 | Fuel Heater | |
| 5 | 4 | Hard Washer | |
| 6 | 4 | Bolt | |
| 7 | 1 | Elbow | |
| 8 | 4 | O-Ring Seal | |
| 9 | 4 | O-Ring Seal | |
| 10 | 1 | Elbow | |
| 11 | 2 | Connector | |
| 12 | 4 | O-Ring Seal | |
| 13 | 2 | Elbow | |
| 14 | 1 | Connector | |
| 15 | 1 | O-Ring Seal | |
| 16 | 1 | Connector | |
| 17 | 1 | O-Ring Seal | |
| 18 | 1 | Hose As | |
| 19 | 1 | Hose As | |
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| Parts To Cap the Fuel Recirculation Line | |||
|---|---|---|---|
| Item | Qty | Part Number | Part Name |
| 20 | 1 | Cap As | |
| 21 | 1 | Plug | |
| 22 | 2 | O-Ring Seal | |
Procedures
- Ensure that proper winter fuel blend is being used for the ambient temperatures.
- If a fuel heater is not already installed, install 478-5442 Fuel Heater Gp. The heater will mix the warm fuel returning from the engine with cold fuel from the tank prior to filters. Refer to Section "Procedure to Install Fuel Heater".
Note: Only if steps 1 and 2 did not resolve fuel gelling, continue to step 3.
- Temporally cap the fuel recirculation line to force all the fuel from the engine to the fuel heater group. Once the weather has started to warm, this line should be reconnected for normal operation. Refer to Section "Procedure to Install Temporary Cap"
Procedure to Install Fuel Heater
- Remove hose (A) and hose (B) from adapter elbows (3). Remove and discard adapter elbows (C) from the fuel tank.
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Illustration 2 g06203041 Left side view of the fuel tank
(1)479-0059 Plate As
(2)8T-4121 Hard Washer
(3)8T-4136 Bolt - Install plate assembly (1) to the tank using washers (2) and bolts (3).
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Illustration 3 g06203073 Left side view of the fuel tank
(1)479-0059 Plate As
(2)8T-4121 Hard Washer
(4)357-7434 Fuel Heater
(5)397-9301 Hard Washer
(6)8T-6466 Bolt - Install fuel heater (4) to plate assembly (1) using washers (5), washers (2), and bolts (6).
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Illustration 4 g06203162 Left side view of the fuel tank
(4)357-7434 Fuel Heater
(7)6V-9182 Elbow
(8)238-5084 O-Ring Seal
(9)228-7092 O-Ring Seal - Install elbow (7) into fuel heater (4) with O-ring seal (8) and O-ring seal (9).
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Illustration 5 g06203172 Left side view of the fuel tank
(4)357-7434 Fuel Heater
(8)238-5084 O-Ring Seal
(9)228-7092 O-Ring Seal
(10)8T-4149 Elbow - Install elbow (10) into fuel heater (4) with O-ring seal (8) and O-ring seal (9).
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Illustration 6 g06203199 Left side view of the fuel tank
(4)357-7434 Fuel Heater
(8)238-5084 O-Ring Seal
(11)138-7538 Connector
(12)228-7091 O-Ring Seal - Install two connectors (11) into fuel heater (4) with O-ring seal (8) and O-ring seal (12).
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Illustration 7 g06203229 Left side view of the fuel tank
(4)357-7434 Fuel Heater
(11)138-7538 Connector
(12)228-7091 O-Ring Seal
(13)6V-9852 Elbow - Install two elbows (13) to connectors (11) on fuel heater (4). Install O-rings (12) into elbow adapters (13).
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Illustration 8 g06203308 Left side view of the fuel tank
(9)228-7092 O-Ring Seal
(14)6V-9874 Connector
(15)238-5080 O-Ring Seal - Install connector (14) into the fuel tank with O-ring seal (9) and O-ring seal (15).
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Illustration 9 g06203332 Left side view of the fuel tank
(9)228-7092 O-Ring Seal
(16)6V-8637 Connector
(17)238-5082 O-Ring Seal - Install connector (16) into the fuel tank with O-ring seal (9) and O-ring seal (17).
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Illustration 10 g06203356 Left side view of the fuel tank
(10)8T-4149 Elbow
(14)6V-9874 Connector
(18)339-7876 Hose As - Install hose assembly (18) to connector (14) on the fuel tank and elbow (10) on the fuel heater.
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Illustration 11 g06203530 Left side view of the fuel tank
(7)6V-9182 Elbow
(16)6V-8637 Connector
(19)339-7875 Hose As - Install hose assembly (19) to connector (16) on the fuel tank and elbow (7) on the fuel heater.
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Illustration 12 g06203603 Left side view of the fuel tank
(A) Hose (fuel inlet - return from engine)
(B) Hose (fuel outlet - to fuel filter)
(13)6V-9852 Elbow - Install hose (A) and hose (B) to elbows (13) on the fuel heater.
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| Illustration 1 | g06203004 |
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Left side view of the fuel tank (A) Hose (fuel inlet - return from engine) (B) Hose (fuel outlet - to fuel filter) (C) Adapter elbow | |
Procedure to Install Temporary Cap
- Disconnect hose (D) from connector (E) on the fuel manifold.
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Illustration 14 g06204031 Front side view
(D) Hose
(E) Connector
(20)6V-9831 Cap As
(21)6V-9510 Plug
(22)228-7091 O-Ring Seal - Install cap (20) and O-ring (22) to hose (D).
- Install plug (21) and O-ring (22) to connector (E) on the fuel manifold.
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| Illustration 13 | g06203665 |
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Location of the valve. Left-hand side of the frame. (D) Hose (E) Connector | |
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