N14 Base Engine Troubleshooting and Repair Manual – 002-004   Cylinder Head

WARNING  Do not remove the pressure cap from a hot engine. Wait until the coolant temperature is below 50°C [120°F] before removing the pressure cap. Heated coolant spray or steam can cause personal injury.

Drain the cooling system. Refer to Procedure 008-018.

Remove the charge air cooler connections or tube.

Remove the crankcase breather. Refer to Procedure 003-001.

Remove the rocker lever covers. Refer to Procedure 003-011.

Remove the air intake manifold assembly. Refer to Procedure 010-023.

Remove the turbocharger. Refer to Procedure 010-033.

Remove the exhaust manifold. Refer to Procedure 011-007.

Remove the injector wiring harness connectors.

Remove the engine brake if equipped. Refer to Procedure 020-001.

Remove the rocker lever assemblies. Refer to Procedure 003-009.

Remove the push rods. Refer to Procedure 004-014.

Mark the location and orientation of the valve crossheads.

Remove the valve crossheads.

Remove the fuel supply and the fuel drain tubes.

Remove all the necessary brackets and clamps.

Disconnect the injector wiring at the pass through connector.

Remove the injector. Refer to Procedure 006-026.

Remove the rocker lever housing. Refer to Procedure 003-013.

Remove the two fuel crossover connections and the o-rings.

WARNING  This component weighs 23 kg [50 lb or more. To reduce the possibility of personal injury, use a hoist or get assistance to lift this assembly.

To prevent increased wear, mark each cylinder head as it is removed so it can be installed back in its original location.

Remove the 12 capscrews and washers from each cylinder head.

Lift the cylinder heads from the block, and remove the cylinder head gaskets.

Inspect the push rods. Refer to Procedure 004-014.

Put a clean, lint-free rag into each push rod cavity in the cylinder block, and plug the overhead oil supply rifle.

Use a gasket scraper to remove heavy dirt and debris from the head gasket surface of the cylinder block.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

Use a razor blade scraper and solvent to remove any remaining material from the cylinder block surface.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Clean with solvent, and dry with compressed air.

Remove the rags after the cylinder block is cleaned.

WARNING  When using a steam cleaner, wear safety glasses or a face shield, as well as protective clothing. Hot steam can cause serious personal injury.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Steam clean the cylinder heads, and dry with compressed air.

Blow out all capscrew holes, fuel passages, and oil passages.

Use a gasket scraper to remove heavy dirt and debris from the cylinder head gasket surface and the exhaust manifold gasket surface.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

Use a razor blade scraper and solvent to remove any remaining material from the cylinder head gasket surface and the exhaust manifold gasket surface.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Clean with solvent, and dry with compressed air.

Clean the rocker lever housing gasket surface on each cylinder head.

Inspect the cylinder heads for cracks or damage.

If a crack in a cylinder head is suspected, pressure test the cylinder head.

Inspect the valves for indications of leakage or burning.

If indications of leakage or burning are found, the valves and the seats must be resurfaced. Refer to the N14 Shop Manual, Bulletin 3810487.

Mark each valve as it is removed to identify its location in the cylinder head.

Use valve spring compressor stand, Part Number ST-1022, and valve spring compressor plate, Part Number ST-1026, to remove the valves.

Install two injector sleeve holding tools, Part Number ST-1179, into each cylinder head.

The following components are included in the injector sleeve holding:

• Hexagon head capscrew
• Flat washer
• Anvil, Part Number ST-1179-4
• Mandrel, Part Number ST-1179-2
• Hexagon head capscrew.

Tighten the injector sleeve holding tool capscrews.

Install the cylinder head in hydrostatic tester, Part Number ST-1012, and hydrostatic tester adapter plate, Part Number ST-1013.

Connect a regulated air supply hose to the test fixture plate.

Apply 280 kPa [40 psi] air pressure.

Use a hoist to place the cylinder head in a tank of warm water heated to 60°C [140°F].

Completely submerge the cylinder head in the water.

Inspect for air bubbles rising from the water.

If air bubbles are seen, replace or rebuild the cylinder head. Refer to the N14 Shop Manual, Bulletin 3810487 for rebuild procedures.

Remove the test equipment.

Install the valves in their original positions in the cylinder head and the valve springs in the cylinder head as follows:

A. Valve

B. Valve Spring Guide and Stem Seal

C. Valve Spring

D. Valve Spring Retainer

E. Collets

Test the cylinder head for damage.

Set the head down with the intake ports on the bottom.

Pour fuel into the exhaust port until it is full.

Set the container of fuel down and start the timer.

If a drop of fuel drips or runs down the face of the head within 30 seconds, the exhaust valves and the seats must be resurfaced. Refer to the N14 Shop Manual, Bulletin 3810487.

If a drop of fuel has not run down the face of the head in 30 seconds, the exhaust side is okay.

Drain the fuel from the exhaust side of the head.

Turn the head over so the exhaust port is on the bottom.

Pour fuel into the intake ports until full.

Set the container of fuel down and start the timer.

If a drop of fuel drips or runs down the face of the head within 30 seconds, the intake valves and the seats must be resurfaced. Refer to the N14 Shop Manual, Bulletin 3810487.

If a drop of fuel has not run down the face of the head in 30 seconds, the intake side is okay.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

CAUTION  Do not use caustic or acid solutions to clean the cylinder head capscrews.

Use a petroleum-based solvent to clean the capscrews.

Clean the capscrews thoroughly with a wire brush, with a wire wheel (soft), or use a non-abrasive bead blast to remove deposits from the shank and the threads.

Inspect the cylinder head capscrews for damaged threads, corroded surfaces, or a reduced diameter (because of capscrew stretching).

Do not use a capscrew that has damaged threads or a reduced diameter from having been stretched.

Do not use cylinder head capscrews under the following conditions:

• Visible corrosion or pitting exceeds 1 sq. cm [0.155 sq. in] in area.

  For example, acceptable is 0.952 x 0.952 mm [3/8 x 3/8 in] and not acceptable is 12.7 x 12.7 mm [½ x ½ in]

• Visible corrosion or pitting exceeds 0.12 mm [0.005 in] in depth.

• Visible corrosion or pitting is located within 3.2 mm [1/8 in] of the fillet.
• Visible corrosion or pitting is located within 3.2 mm [1/8 in] of the threads.

Using flange head capscrews with the torque plus angle method of installation places the capscrew beyond the yield point, and permanently stretches the capscrew at each use. These capscrews can be reused throughout the life of the engine unless the capscrew exceeds the specified free length. The capscrew free length must be checked to avoid bottoming out in the cylinder block during installation.

Use capscrew length gauge, Part Number 3823546, to check capscrew free length.

The capscrews can be checked by using a set of calipers if capscrew length gauge, Part Number 3823546, is not available.

The maximum allowable free length (dimension `X’), measured from the bottom of the flange to the end of the capscrew, is 185.6 mm [7.310 in].

To check the capscrew free length, place the head of the capscrew in the appropriate slot with the flange against the base of the slot.

Capscrew length must be checked without the hardened washer.

If the end of the capscrew touches the foot of the gauge, the capscrew is too long and must be discarded.

The capscrew can be used again if there is clearance between the end of the capscrew and the bottom base of the tool.

Immediately after cleaning and inspecting, apply a film of clean engine lubricating oil to capscrews that are to be used again.

Install new gaskets on the dowel pins in the cylinder block.

Make sure the side of the gasket marked “TOP” is up.

Install the cylinder heads in their original locations over the dowel pins.

Use clean 15W-40 oil to lubricate the cylinder head capscrews and both sides of the flat washers.

Allow the excess oil to drain from the threads.

Install 12 capscrews and washers in each cylinder head.

Complete the following steps to tighten the capscrews to the specified torque values in the sequence shown:

Not less than one flat, and not more than two flats.

Repeat the tightening sequence to install each cylinder head.

The markings on the head of the flange head capscrews serve as an aid during installation.

After tightening the capscrew to 298 N•m [220 ft-lb], mark the cylinder head adjacent to one of the two single marks “A” or “B” on the capscrew head.

After all 12 capscrews on one head have been tightened to 298 N•m [220 ft-lb], they must be rotated in the tightening direction an additional 90 degrees. Rotate the capscrew until the mark on the cylinder head is between the next two marks joined by an arc (more than one flat and less than two flats).

When using torque plus angle, the tolerance on the 90 degree angle of rotation is one to two flats (90°± 30°). If the capscrew is rotated beyond two flats, do not loosen the capscrew.

The clamp load is still acceptable; however, rotating the capscrew beyond two flats causes additional stretch and reduces the number of reuses.

With correct tightening, the capscrew can typically be reused for the life of the engine.

Use new o-rings and install the fuel crossover connections.

Tighten the capscrews.

Install the rocker lever housings. Refer to Procedure 003-013.

Install the injectors and the hold down clamps. Refer to Procedure 006-026.

Install the CELECT™ injector solenoid wire connector to the pass through connector.

Install the fuel supply and the fuel drain tubes.

Install all the brackets and the clamps.

Install the valve crossheads in their original location and orientation.

Lubricate the valve stems with clean 15W-40 oil.

The large pocket of the crosshead goes toward the exhaust side.

Use a wire gauge to check the clearance between the crosshead and the valve spring retainer. The clearance must be a minimum of 0.65 mm [0.025 in].

Install the push rods into their original location. Refer to Procedure 004-014.

Install the rocker lever assemblies. Refer to Procedure 003-009.

Adjust the valves and the injectors. Refer to Procedure 003-004.

On CELECT™ engines, connect the injector wiring harness connector.

Install the exhaust manifold. Refer to Procedure 011-007.

Install the turbocharger. Refer to Procedure 010-033.

Install and adjust the brakes, if applicable. Refer to Procedures 020-001.

Install the air intake manifold assembly. Refer to Procedure 010-023.

Install the rocker lever covers with the original reusable gaskets if they are not damaged. Refer to Procedure 003-011.

Install the charge air cooler connections or tubes.

Install the crankcase breather. Refer to Procedure 003-001.