3406B (PEEC) DIESEL TRUCK ENGINE Caterpillar

Start By:

a. remove valve covers

1. Disconnect solenoid lead wires (1) and (3) from the terminal in the Jacobs spacer.

2. Remove eight Jacobs nuts (2) and four Jacobs bolts that hold the Jacobs spacers to the valve cover bases. Remove Jacobs spacers (4).

NOTE: Do Steps 3 through 10 for each end of the engine. The front half of the engine is shown.

3. Remove four Jacobs studs (5) and Jacobs washers. Remove three bolts (6) and remove valve cover base (7).

4. Remove Jacobs nuts (8), Jacobs washers, Jacobs bolts (9), and the Jacobs washers that hold the Jacobs brake housing assembly in place.

5. Remove Jacobs brake housing assembly (10).

NOTE: The Jacobs brake for the 3406B Truck Engine has only one support bracket (11).

6. Remove Jacobs head bolts (12), and remove Jacobs support brackets (11) from the cylinder head.

7. Remove inner fuel lines (13).

8. Remove Jacobs washers (14) and Jacobs shims (15) from the Jacobs stud assemblies.

9. Remove bolt (17) and two Jacob stud assemblies (16) that hold the rocker shaft assembly to the head. Remove rocker shaft assembly (18).

10. Remove Jacobs exhaust valve bridges (20) from the exhaust valves only. The intake valves have the Caterpillar intake valve bridges. Remove the Caterpillar intake valve bridges (19).

Install Jacobs Engine Brake

NOTE: Do each step for each end of the engine. The front half is shown.

1. Put clean engine oil on the bridges and dowels.

2. Install Jacobs exhaust valve bridges (20) and the Caterpillar intake valve bridges (19) on the dowels.

3. Keep hand pressure on the bridges, and turn the adjustment screw clockwise until contact is made with the valve stem. Turn the screw an extra 20° to 30°. This will make the dowel straight in the guide and compensate for gap (slack) in the threads. Hold the adjustment screw in this position, and tighten the locknut to a torque of 28 ± 4 N·m (21 ± 3 lb.ft.).

4. Put rocket shaft assembly (18) in position on the cylinder head.

5. Install Jacobs washers (21) on the Jacobs stud assemblies (16). Put clean oil on the threads, and install washer and bolt (17) and Jacobs stud assemblies (16). Tighten the center bolt and Jacobs stud assemblies in increments of 70 N·m (50 lb.ft.) each until a final torque of 450 N·m (330 lb.ft.) is obtained.

6. Make an adjustment to the valves to have a clearance of .015 (.038 mm) for the intake valves and .030 (0.76 mm) for the exhaust valves. Tighten the locknuts to a torque of 28 ± 4 N·m (21 ± 3 lb.ft.), and check the valve clearance again. See Testing And Adjusting for the correct procedure.

7. Install a new Jacobs O-ring seal (22) on the Jacobs oil supply adapter in the rocker shaft assembly. Put clean oil on the Jacobs O-ring seal.

8. Install inner fuel lines (13). Tighten the fuel line nuts to a torque of 40 ± 7 N·m (30 ± 5 lb.ft.) with tooling (A) and (B).

NOTE: The Jacobs brake for the 3406B Truck Engine has only one support bracket (11).

9. Put Jacobs support brackets (11) in position as shown. Put oil on the threads of Jacobs bolts (12). Install the washers on the Jacobs bolts. Install Jacobs bolts (12) that hold the Jacobs support bracket in place. Tighten Jacobs bolts to a torque of 450 N·m (330 lb.ft.).

10. Install Jacobs washers (14) on the Jacobs stud assemblies.

NOTE: The brake housing assembly with the mark "FRONT" on it must be installed on the front three cylinders. The brake housing assembly with the mark "REAR" must be install on the rear three cylinders.

11. Puts Jacobs brake housing assembly (10) in position on the engine.

12. Install the Jacobs washers and Jacobs bolts (9) that hold the Jacobs brake housing assembly to the Jacobs support brackets. Tighten the Jacobs bolts to a torque 14 N·m (10 lb.ft.).

13. Use feeler gauge (23) as shown, and measure the gap between the Jacobs brake housing assembly and the Jacobs washer at each end of the Jacobs brake housing assembly.

14. Measure the thickness of Jacobs shim packs (15). Use a knife to make a separation of the shimpacks. Measure the shim packs again. Do this until the shim packs are the same thickness as the gaps measured in Step12.

15. Remove the Jacobs brake housing assembly, and remove the Jacobs washers from the Jacobs stud assemblies.

16. Install correct Jacobs shim packs (15) on the Jacob stud assemblies. Install Jacobs washers (14).

17. Put Jacobs brake housing assembly (10) in position on the engine.

18. Install Jacobs washers and Jacobs nuts (8). Install Jacobs washers and Jacobs bolts (9). Tighten Jacobs nuts (8) to torque of 135 N·m (100 lb.ft.). Tighten Jacobs bolts (9) to torque of 64 N·m (48 lb.ft.).

19. Use two feeler gauges (23) as shown, and make an adjustment to the slave piston clearance (lash) at any cylinder location where the exhaust valves are closed. Turn adjustment screw (24) for the correct clearance (lash). For the correct clearance see the Subject, Jake Brake Adjustment in Testing And Adjusting.

20. Tighten locknuts (25) after the clearance (lash) has been made.

21. Put valve cover base (7) in position on the cylinder head.

22. Check to make sure there is no contact between the No. 3 and the No. 6 exhaust valve bridges and the valve cover bases at area (X) as shown.

NOTE: It will be necessary to remove material from the valve cover bases if there is contact between them.

23. Install Jacobs washers (26) on the studs. Install Jacobs studs (5) in the four locations shown with the short threaded end toward the cylinder head. Install bolts (6). Tighten Jacobs studs (5) and bolts (6) to a torque of 13.6 ± 2.8 N·m (120 ± 24 lb.in.)

24. Put Jacobs spacer (4) in position on top of the valve cover bases.

25. Install Jacobs nuts (2) on the Jacobs studs. Install Jacob bolts (27) that hold the Jacobs spacer in place.

26. Connect solenoid lead wire (1) and (3) to the terminal in the Jacobs spacer.

NOTE: If the engine is in the vehicle, start the engine, let it run at idle speed, and remove (bleed) the air from the Jacobs brake housing assemblies. To remove (bleed) the Jacobs brake housing assemblies for operation immediately, depress the solenoid armature five or six times in sequence with the engine in operation to permit oil to fill the passages in the housing assemblies.

End By:

a. install valve covers