M11 Series – Service Manual – 020-024   Engine Brake

An engine equipped with an engine brake can fail to start or fail to perform properly due to one or more of the following:

• Engine will
  not start due to a stuck oil flow solenoid valve

To check for a stuck solenoid valve, disconnect the electrical connection to the engine brakes and then operate the engine.

If exhaust gases can be heard escaping past the valves, the solenoid valve or valves
must be replaced. Contact an authorized engine brake dealer.

• Engine will
  not start or runs rough because a slave piston was adjusted incorrectly or is damaged

To check the slave piston, remove the rocker lever cover.
Refer to Procedure 003-011 (Rocker Lever Cover) in Section 3.

Check the slave piston clearance. The clearance
must be 0.38 mm [0.015 in].

For engine brake – adjustment, refer to Procedure 003-004 (Overhead Set) in Section 3 to adjust the clearance.

NOTE: If the slave piston is damaged, contact an authorized engine brake dealer for repair.

Inspect the slave piston for damage.

Install the rocker lever cover.
Refer to Procedure 003-011 (Rocker Lever Cover) in Section 3.

• Sudden drop in lubricating oil pressure

Remove the rocker lever cover.
Refer to Procedure 003-011 (Rocker Lever Cover) in Section 3.

NOTE: If repairs are necessary, contact an authorized engine brake dealer.

Operate the engine and check for the following problems:

• Oil supply hose loose or missing
• Oil connector seal loose or missing

• Upper solenoid valve seal ring missing or damaged
• External oil supply hose or fitting cracked or leaking.

Install the rocker lever cover.
Refer to Procedure 003-011 (Rocker Lever Cover) in Section 3.

• Engine misfiring or loss of power.

Remove the rocker lever cover.
Refer to Procedure 003-011 (Rocker Lever Cover) in Section 3.

Adjust the slave piston clearance.
Refer to Engine Brake – Adjustment in Procedure 003-004 (Overhead Set) in Section 3.

Install the rocker lever cover.
Refer to Procedure 003-011 (Rocker Lever Cover) in Section 3.

Remove the rocker lever cover.
Refer to Procedure 003-011 (Rocker Lever Cover) in Section 3.

Disconnect the two electrical wires from the terminals on the inside of the rocker lever housing spacer.

Disconnect the oil supply hose connections.

Press the connector into the front housing to allow clearance for housing removal.

Remove the capscrews and both engine brake housings.

Use an approved solvent to clean the brake housings. Dry with compressed air.

Inspect the housings for any missing or damaged parts.

Apply a thin film of clean 15W-40 oil to the machined surfaces.

Loosen the locknuts on the slave pistons.

Make sure the slave pistons are fully retracted.

Install the rear engine brake housing on the rear rocker lever supports.

Washers are
not used with the capscrews.

Use clean 15W-40 oil to coat the bottom side of the capscrew heads and the threads.

Install the capscrews in the rocker lever supports.

Do
not tighten the capscrews.

Use clean 15W-40 oil to lubricate the o-rings.

Press the connector all the way into the front housing by hand.

When installing the front housing, be sure the oil connector and o-ring are in position to be pushed into the rear housing.

Install the front engine brake housing on the front rocker lever supports.

Center the oil connector between the front and rear housings before tightening the capscrews.

Tighten the capscrews in the sequence shown.

Install the oil connector supply hose and tighten the connection.

Connect the two electrical wires to the terminals on the inside of the rocker lever housing spacer.

Install the rocker lever cover.
Refer to Procedure 003-011 (Rocker Lever Cover) in Section 3.

To obtain maximum brake operating efficiency, the engine brakes
must be adjusted.
Refer to Overhead Adjustment in Procedure 003-004 (Overhead Set) in Section 3 for the correct engine brake adjusting procedure.