3408C, 3412C and 3412D High Performance Marine Engines Caterpillar

Type 1

Fuel Injection Pump and Governor

Illustration 1	g01024785
Right side view Typical example

(1) Tighten the bushing to the following torque. ... 270 ± 13 N·m (200 ± 10 lb ft)

(2) Pin hole for zero rack (LH)

(3) Hole for timing pin

(4) Pin hole for zero rack (RH)

(5) Fuel Inlet from secondary filter

(6) Tighten the bolts to the following torque. ... 14 ± 4 N·m (10 ± 3 lb ft)

Illustration 2	g00707963

(7) Fuel return to tank (automatic purge)

(8) Fuel bypass valve

(9) Rotary servo assembly

Illustration 3	g00707967
View E-E

(10) 4N-0605 Spring for servo assembly

Length under test force ... 22.35 mm (0.880 inch)

Test force ... 15.70 ± 0.80 N (3.53 ± 0.18 lb)

Free length after test ... 43.92 mm (1.729 inch)

Outside diameter ... 13.39 mm (0.527 inch)

Illustration 4	g00707969
View F-F

(11) The inside diameter of servo assembly for the oil pump rotor ... 12.706 ± 0.006 mm (0.5002 ± 0.0002 inch)

(12) The inside diameter of the shaft bearing ... 12.720 ± 0.013 mm (0.5008 ± 0.0005 inch)

(13) Shaft diameter ... 12.682 ± 0.008 mm (0.4993 ± 0.0003 inch)

Note: The shaft must rotate freely after the cover is tightened.

Illustration 5	g00707971
View C-C

(14) 9Y-6083 Spring (Regulating fuel pressure)

Length under test force ... 26.24 mm (1.033 inch)

Test force ... 13.4 ± 0.7 N (3.01 ± 0.15 lb)

Free length after test ... 43.31 ± 0.91 mm (1.705 ± 0.036 inch)

Outside diameter ... 13.48 mm (0.531 inch)

(15) Lubricate the seal lightly with the diesel fuel.

Illustration 6	g00368717
View A-A

Illustration 7	g00707973
View G-G

(16) Lubricate the seal lightly with glycerin.

(17) Tighten the nut to the following torque. ... 8 ± 5 N·m (71 ± 44 lb in)

(18) Tighten the solenoid assembly to the following torque. ... 70 ± 10 N·m (50 ± 7 lb ft)

(19) 1N-3801 Link Spring

Length under test force ... 26.23 mm (1.033 inch)

Test force ... 4.5 ± 0.2 N (1.00 ± 0.05 lb)

Free length after test ... 49.29 mm (1.941 inch)

Outside diameter ... 11.32 mm (0.446 inch)

Illustration 8	g00707974
View H-H

(20) Lubricate the seal lightly with glycerin.

(21) With the fuel rack at zero position, adjust the sensor's output (control group), as required.

(22) Torque for nut ... 55 ± 7 N·m (41 ± 5 lb ft)

Adjust the compression stroke's static timing under these conditions:

• the No. 1 Cylinder is at the TC position of the compression stroke.

• the timing slot for the fuel pump camshaft is at the TC position.

• the timing pin is installed in the timing hole inside the fuel pump housing.

Adjust the static timing to the following value:

Static timing for 3408 engines ... 19.5° before top center

Static timing for 3412 engines ... 18° before top center

Illustration 9	g00707976
View D-D

(23) Fuel outlet to secondary fuel filter

(24) Fuel inlet from primary fuel filter

Fuel Injection Pump

Illustration 10	g01024934

(1) Fuel rack

Diameter of the fuel rack ... 12.662 ± 0.005 mm (0.4985 ± 0.0002 inch)

Bore in the fuel rack bearings after installation into the housing ... 12.767 ± 0.058 mm (0.5026 ± 0.0023 inch)

(2) Plate assembly and adapter

Install the alignment dowels into the plate assembly to the following depth. ... 6.0 ± 0.5 mm (0.24 ± 0.02 inch)

Install the locator pin into the adapter to the following depth. ... 6.0 ± 0.5 mm (0.24 ± 0.02 inch)

The bore that is in the plate assembly for the adapter is the following dimension. ... 28.615 ± 0.008 mm (1.1266 ± 0.0003 inch)

(3) Tighten the bushing to the following torque. ... 270 ± 13 N·m (200 ± 10 lb ft)

(4) Fuel injection pump

(5) Spacer

Thickness of 7E-9907 Spacer ... 6.761 ± 0.005 mm (0.2662 ± 0.0002 inch)

(6) Lifter assembly

(7) Camshaft assembly

Diameter of the bearing journals for the camshaft assembly ... 74.000 ± 0.013 mm (2.9134 ± 0.0005 inch)

Width of the groove that is machined into the camshaft for the thrust plate ... 4.63 ± 0.05 mm (0.182 ± 0.002 inch)

Width of the thrust plate for the camshaft ... 4.500 ± 0.025 mm (0.1772 ± 0.0010 inch)

Illustration 11	g01024939

(8) Pump bonnet

(9) 8N-5993 Flow Check Spring

Length under test force ... 11.50 mm (0.453 inch)

Test force ... 151 ± 8 N (34 ± 2 lb)

Free length after test ... 15.81 mm (0.622 inch)

Outside diameter ... 10.36 mm (0.408 inch)

(10) 1W-6985 Flow Check Spring

Length under test force ... 7.63 mm (0.300 inch)

Test force ... 8.3 ± 0.8 N (1.87 ± 0.20 lb)

Free length after test ... 8.54 mm (0.336 inch)

Outside diameter ... 3.2 mm (0.13 inch)

(11) Retainer spring

(12) Plunger and barrel assembly

(13) 118-0540 Spring

Length under test force ... 48.87 mm (1.924 inch)

Test force ... 210 ± 10 N (47 ± 2 lb)

Free length after test ... 53.87 mm (2.122 inch)

Outside diameter ... 34.11 mm (1.343 inch)

Type 2

Fuel Injection Pump and Governor

Illustration 12	g01024999

(1) Tighten the bushing to the following torque. ... 163 ± 14 N·m (120 ± 10 lb ft)

(2) Governor assembly

Illustration 13	g01025005

(3) The shaft seals must be flush with the face of the housing.

Illustration 14	g01025012
View B-B

(4) Tighten the nut to the following torque. ... 12 ± 4 N·m (105 ± 35 lb in)

(5) 6N-8793 Spring

Length after assembly ... 19.05 mm (0.750 inch)

Load at assembled length ... 2.0 ± 0.1 N (0.45 ± 0.03 lb)

Free length after test ... 41.9 mm (1.65 inch)

Inside diameter ... 8.38 mm (0.330 inch)

(6) 4N-6681 Spring

In order to test for the spring rate, preload the spring to 5.4 N·m (4.00 lb ft). Compress the spring for an additional distance of 22.8600 mm (0.900 inch). Total load on the spring should be the following value. ... 2.01 ± 0.65 N·m (1.48 ± 0.48 lb ft)

Free length after test ... 56.9 ± 1.0 mm (2.24 ± 0.04 inch)

Inside diameter ... 30.20 ± 0.38 mm (1.189 ± 0.015 inch)

Color code ... two purple stripes

(7) 2W-3397 Spring

Length after assembly ... 9.08 mm (0.358 inch)

Load at assembled length ... 5.79 ± 0.29 N (1.30 ± 0.07 lb)

Free length after test ... 17.34 ± 1.00 mm (0.683 ± 0.039 inch)

Inside diameter ... 9.79 ± 0.13 mm (0.3854 ± 0.005 inch)

Color code ... one orange stripe

Prior to installing pin assembly (8), you must first align the marks that are on the gear (9), stop (10), and pinion (11).

Illustration 15	g01025050

(12) Governor housing

(13) Distance between the bearings ... 2.385 ± 0.005 mm (0.0939 ± 0.0020 inch)

Illustration 16	g01025048
View D-D

(14) 7M-7316 Spring

Length after assembly ... 43.7 mm (1.72 inch)

Load at assembled length ... 250 to 2800 N (57 to 63 lb)

Free length after test ... 54.76 mm (2.156 inch)

Outside diameter ... 11.53 ± 0.13 mm (0.454 ± 0.005 inch)

Illustration 17	g01025041
View C-C

(15) Tighten the insulator to the following torque. ... 4.5 ± 0.5 N·m (40 ± 5 lb in)

Illustration 18	g01025062

(16) Plate assembly

(A) The dowel should extend above the plate for the following distance. ... 7.9 ± 0.5 mm (0.31 ± 0.02 inch) (B) The dowels that are pressed through the plate should extend below the plate for the following distance. ... 5.6 ± 0.5 mm (0.22 ± 0.02 inch)

Fuel Injection Pump

Illustration 19	g01025075

(1) Fuel injection pump

(2) 8N-1415 Spring

Length under test force ... 8.69 mm (0.3421 inch)

Test force ... 111.21 ± 6.45 N (25.001 ± 1.450 lb)

Free length after test ... 12.12 mm (0.477 inch)

Outside diameter ... 9.78 mm (0.385 inch)

(3) 7N-1208 Spring

Length under test force ... 29.26 mm (1.152 inch)

Test force ... 325 ± 16 N (73 ± 4 lb)

Free length after test ... 48.03 mm (1.891 inch)

Outside diameter ... 25.27 mm (0.995 inch)

(A) Thickness of spacers

9N-6496 Spacer ... 4.12 mm (0.162 inch)

9N-6495 Spacer ... 4.22 mm (0.166 inch)

5M-2697 Spacer ... 4.32 mm (0.170 inch)

2M-4208 Spacer ... 4.42 mm (0.174 inch)

2M-4209 Spacer ... 4.52 mm (0.178 inch)

2M-4210 Spacer ... 4.62 mm (0.182 inch)

2M-4211 Spacer ... 4.72 mm (0.186 inch)

2M-4212 Spacer ... 4.83 mm (0.190 inch)

5M-2691 Spacer ... 4.93 mm (0.194 inch)

5S-7189 Spacer ... 5.03 mm (0.198 inch)

(B) Dimensions for the fuel injection pump plunger

Length of a new pump plunger ... 69.118 ± 0.013 mm (2.7212 ± 0.0005 inch)

Minimum length of a pump plunger that may be reused ... 69.079 mm (2.7196 inch)

(C) Dimensions for the fuel rack

Diameter of a new fuel rack ... 12.668 ± 0.005 mm (0.4987 ± 0.0002 inch)

Bearing bore in the front of the pump housing after installation of the bearing ... 12.758 ± 0.038 mm (0.5023 ± 0.0015 inch)

Bore in the rear of a new pump housing ... 12.758 ± 0.038 mm (0.5023 ± 0.0015 inch)

Maximum clearance between a rack and bearings that are worn ... 0.18 mm (0.007 inch)

(D) Camshaft bearing journals

Bore in the camshaft bearing after installation into the fuel pump housing ... 53.988 ± 0.038 mm (2.1255 ± 0.0015 inch)

Diameter of the camshaft bearing journals ... 53.899 ± 0.013 mm (2.1220 ± 0.0005 inch)

Maximum clearance between a camshaft and bearings that are worn ... 0.25 mm (0.010 inch)

Illustration 20	g01025309

(4) Use the 5P-4158 Gauge (Fuel Injection Timing) to measure the timing dimension.

Install the correct spacer thickness (E) in order to obtain the necessary timing dimension (F) .

Timing dimension with the pump on the engine ... 106.487 ± 0.051 mm (4.1924 ± 0.0020 inch)

Timing dimension for bench test ... 110.335 ± 0.013 mm (4.3439 ± 0.0005 inch)