Series 60 – Cylinder Compression Test

Perform the following steps for a compression test on a Series 60 Engine:
1.Start and run the engine until normal operating temperature is reached. Stop the engine.
2. Disconnect the batteries.
3. Disconnect the fuel pump feed line from the fuel tank. Place a suitable container under the line to catch the spilling fuel. Turn the 1⁄4 turn valve off on the outlet fitting of the secondary fuel filter.
4. Disconnect the fuel supply line to the cylinder head. Place a suitable container under the line to catch the spilled fuel. Disconnect the fuel return line from the doser valve and place a suitable container under the line to catch the spilled fuel.
5.Blow low pressure regulated air no more than 207 kPa (30 psi ) into the inlet fitting for 20
to 30 seconds or until all the fuel is purged from the head.
6. Clean and remove the rocker cover, it is not necessary to remove the bottom rocker cover.
If equipped with Jake Brakes remove the Jake Brake assembly.
7. Remove all the rocker shaft mounting bolts and nut from the front or rear rocker shaft assembly. Using rocker arm lifter (J–35996–A), see Figure 6-2, lift the assembly straight up and off of the head and place in a clean area on the bench.

8.Use tool J-47808 to remove the 4–pin electrical connection from the injector.
9. Disengage the locking tang on the harness plug connection, grasp the connector and gently pull it from the socket.
10. Remove the injector hold down clamps.
11. Remove the three injectors to be tested from the cylinder head.
12. Place the compression test adaptors (J-47373) into the injector holes. It is recommended to have three test adaptors (J-47373) when performing this routine.
13. Install the injector hold down clamps and torque hold down bolts to 58-66 N·m (43-49 lb·ft).
14. Carefully remove the shaft from the rocker arm assembly by slowly pulling it out of the assembly. Place the shaft on the bench. Do not disturb the stack-up of the rocker arm sets.
15. Remove the three injector rocker arms and replace with spacers (J–38768–5) .
16. Lubricate the shaft with clean engine oil. With sleeves in place, carefully reinstall the shaft through each rocker arm shaft. Make sure cup plug end faces inboard.
17. Install the modified rocker arm shaft assembly on the head. If the engine is equipped with
a Jake Brake®, use non-Jake Brake rocker arm shaft bolts 8929129. Torque the three bolts
and the nut to 102-108 N·m (75-80 lb·ft).

NOTE:
Verify that the bolt holes for the rocker shafts are clean as not to hydro lock the bolts
causing damage to the cylinder head.

18. Disconnect both connectors at the valve cover for the injectors.

NOTE:
Disconnect both connectors at the valve cover for the injectors.

19. Attach cylinder compression gauge (J–6692–B) to the first adaptor. See Figure 6-3.

20.Reconnect the batteries.
21. Crank the engine over using the starter motor 5 compression strokes record the compression reading on the gauge.

NOTE:
Verify that the batteries voltage does not go low enough to affect engine cranking speed.
If the cranking speed is affected then the results will be inaccurate. If needed connect a
battery charge to maintain battery voltage.

22.The compression reading should be 3102-3793 kPa (450-550 psi) with no two cylinders
differing by more than 276 kPa (40 psi). If compression readings are below specifications,
repeat step 20 to be certain of the reading.

23.After testing all three cylinders, remove bolts from the modified rocker arm shaft assembly and, using rocker arm lifter (J–35996), lift the assembly straight up and off the cylinder
head. Place in a clean area on the bench.
24. Carefully remove the shaft from the rocker arm assembly, remove the three rocker arm sleeves. Replace the three injector rocker arms. Lubricate the shaft with clean engine oil and carefully reinstall through each rocker arm.
25. Remove the injector hold down clamps discard the hold down bolt and remove the compression test adaptors from the cylinder head.
26. Using new sealing rings and injector hold down bolt install the injectors back into the cylinder head and torque to specifications; Torque bolt to 50 Nm (37 lb ft) Loosen the bolt 60 degrees ( 1/6 of a turn or one bolt flat) Do not fully loosen the bolt. Torque the bolt to 35 Nm (26 lb ft) Tighten the bolt an additional 90 degrees.
27. Replace the completed rocker arm shaft assembly on the engine and torque nut and bolts to specifications torque to 102-108 N•m (75-80 lb•ft)
28. Repeat steps 4b-26 for the rear 3 cylinders
29. Install upper valve cover, insuring that the bolt hole are clear of dirt and oil as not to
damage the lower rocker cover.
30. Check test results