Cummins ISX11.9 CM2250 – Service Manual 001-026   Cylinder Block

• Disassemble the engine to cylinder block component level.  Use the procedures in Section DS (Engine Disassembly).
• Remove the cup plugs. Refer to Procedure 017-002 in Section 17.
• Remove the straight thread plugs. Refer to Procedure 017-011 in Section 17.
• Remove the camshaft bushings. Refer to Procedure 001-010 in Section 1.

Before cleaning or further disassembly of the block, perform an inspection to see if there is any damage (cracks, fretting, etc.) that would prohibit reuse. If any cracks are found, the cylinder block must be replaced.

Pay close attention to areas of the block that include:

• Main bearing caps and bores
• Camshaft bores
• Cylinder bores
• Cylinder block combustion deck
• Oil pan mounting surface
• Lubricating oil pump mounting area
• Water pump mounting area
• Front and rear of block sealing surfaces
• Lubricating oil cooler cavity
• Cup plug bores
• Threaded bosses.

WARNING  Use caution while handling and cleaning the cylinder block. The cylinder block may contain sharp edges that can cause personal injury.

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  Use care not to damage the machined gasket surfaces.

Use a gasket scraper to clean the cylinder block deck surface.

Use Scotch-Brite™ 7448 abrasive pad, or equivalent, and solvent to remove any residual gasket material from the cylinder block deck surface.

Remove any remaining adhesive sealant from other cylinder block sealing surfaces.

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.

Use clean solvent and a non-metallic brush to clean the block oil drillings.

Dry with compressed air.

NOTE: Cummins Inc. does not recommend any specific cleaning solution.

Remove the block from the engine stand and place the block in a cleaning tank.

Follow the instructions of the manufacturer of the cleaning tank and the manufacturer of the cleaning solution.

The best results can be obtained by using a cleaning solution that can be heated to 80°C to 95°C [180°F to 200°F].

Use a cleaning tank that will mix and filter the cleaning solution to get the best results.

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.

Remove the cylinder block from the cleaning tank.

Clean the cylinder head deck surface with safety solvent to remove any residual cleaning solution from the steps above.

Clean the cylinder liner midstop area and remove any corrosion, buildup, or residual o-ring material.

CAUTION  All measurements of the cylinder block must be made when the block is positioned on a flat surface. If the block is mounted on the engine stand, the measurements can be wrong because of distortion.

Measure the cylinder block liner ledge at 4 points.

Cylinder Block Liner Ledge Inside Diameter

If the ledge measurement is greater than 150.992 mm [ 5.945 inches], replace the cylinder block.

Inspect the liner ledge for pitting.

If liner ledge pitting is discovered during block inspection, the block can be reused if no leak is evident in the liner-to-liner ledge (block) interface.

Liner ledge pitting has an appearance very similar to liner pitting. Contributing factors to its formation are:

• Combustion gases in the cooling system
• Poorly maintained coolant chemistry
• Excessive load reversal at the liner to block contact area.

Liner ledge pitting starts at the radius and progresses towards the center of the bore. In most circumstances this would not be a block malfunction.

Inspect the cylinder liner seat “C” for extreme wear or cracks.

If surface “C” has signs of extreme wear, the cylinder liner seat will require machining and the installation of shims for the correct liner protrusion. See the Repair section of this procedure.

There must not be any coolant leaks past the liner seat and the lower o-ring. Refer to Procedure 001-027 in Section 1.

Clean the main bearing saddles and caps. Make sure to inspect the main bearing caps and main bearing saddle areas for cracks, fretting, and signs of discoloration.

If any cracks are found, the cylinder block must be replaced.

Inspect the main saddles and caps mating surface for fretting.

Fretting appears as a frosted surface or orange peel texture.

Use fine emery cloth to remove burrs from the camshaft bushing bore.

Clean the bushing bores.

Clean the cup plug sealing areas.

Thoroughly clean all gasket sealing surfaces of any remaining gasket residue.

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.

WARNING  Use caution while handling and cleaning the cylinder block. The cylinder block may contain sharp edges that can cause personal injury.

CAUTION  Make sure all the water is removed from the capscrew holes and the oil passages to prevent rust formation in the cylinder block.

Use a soft bristle brush with a long handle to clean all the oil passages.  Pay specific attention to the oil passages indicated in the illustration.

Use a steam cleaner to clean the oil passages.

Dry with compressed air.

Measure the inside diameter of all the cylinder block camshaft bores.

Camshaft Bore Inside Diameter

If the inside diameter of any bore is not within specifications, the bore must be repaired.

Measure the inside diameter of all the main bearing bores. The inside diameter must be completely round within 0.0130 mm [0.00051 in].

Main Bearing Bore Inside Diameter (Capscrews Tightened to Specification)

Use two centering rings, Part Number 4919372 (131.50 mm [5.177 in] diameter).

Put the rings in the Number 2 and Number 6 main bearing locations.

Use clean 15W-40 oil to lubricate the main bearing capscrew threads and the flat washers.

Drain the excess oil from the capscrews before installation.

CAUTION  The main caps are marked so the number is on the cam side (left side)  and the arrow pointing to the front of the block is to the non-cam (right side) side.The cylinder block identification number (3) is stamped on a pad at the rear of the engine in line with the crankshaft center on the exhaust side of the block. Install the caps in the correct position with the position number to the camshaft side and its part number toward the rear of the engine.

Align the capscrew holes in the cap with the holes in the cylinder block.

Install the capscrews through the cap and into the cylinder block.

Hand tighten the capscrews two to three threads.

Hit the cap with a rubber mallet to push it into the correct position.

The main bearing caps must not have any side clearance with the block. Verify there is not any side clearance, if needed.

Insert the checking ring, Part Number 4919370, into the cylinder block main bearing saddle.

Install the main bearing cap over the checking ring.

Tighten all main bearing capscrews in alternating sequence to the following torque values:

Use clean 15W-40 oil to lubricate the bores of the two centering rings, Part Number 4919372, and the checking bar, Part Number ST-1177-16.

Insert the bar through the centering rings while slowly rotating the bar. The bar must turn easily.

If the bar does not turn easily, check to make sure the main bearing caps are installed correctly. If they appear to be correct, move one of the centering rings to another bearing location.

Slide one end of the bar out of a centering ring.

Slide the checking ring, Part Number 4919370, onto the bar.

Insert the bar into the centering ring.

Apply lubrication to the outside diameter of the checking ring.

Install the checking ring into the main bearing bore by hand. If the ring will not slide through the bore, check the bore for burrs. If the ring will still not slide through the bore, the bore is undersize and must be repaired.

Use a 0.08 mm [0.003 in] feeler gauge that is not more than 13 mm [0.50 in] wide.

Center the checking ring, Part Number 4919370, in the bore.

Try to put the feeler gauge between the checking ring and the bore.

Rotate the gauge in the bore at both sides of the checking ring.

The bore alignment of the main bearing is correct if:

• The gauge does not enter at any point
• The gauge will enter but will not slide through or around the bore and the alignment bar will rotate with the gauge inserted.

The bore alignment of the main bearing is not correct if:

• The gauge enters and slides around the bore. This means that the bore is oversize and must be repaired.
• The gauge will enter on one side only, but can slide around the bore. This means that the bore is tapered and must be repaired.

CAUTION  All measurements of the cylinder block must be made when the block is positioned on a flat surface. If the block is mounted on the engine stand, the measurements can be wrong because of distortion.

Inspect the gasket surfaces.

Inspect for burrs or damage.

Use a burr knife or a crocus cloth to remove the burrs.

Check the top surface of the block for wear.

Fretting or pitting of the cylinder block head deck is not uncommon. It is only detrimental to the head gasket joint if the fretting or pitting is close to the coolant or oil passages. These areas, if damaged, prevent the head gasket from sealing.

If fretting damage, scratches, cracks, or corrosion deeper than 0.08 mm [0.003 in] are present in an area where a head gasket seal ring or a grommet makes contact, the surface must be repaired. There must not be any defect which extends more than 2.41 mm [0.095 in] from the edge of the coolant passage.

Fretting damage in any other area is acceptable if it does not change the protrusion measurement of the cylinder liner.

The cylinder block head deck can be machined to the minimum cylinder block height without the use of an oversize gasket.  However, if the height of the block is less than 399.50 mm [15.728 in], then the cylinder block must be replaced.

Use a 610 mm [24 in] caliper to measure the height of the cylinder block from the center of the main bearing bore to the cylinder head deck surface.

Cylinder Block Height

Use a precision straight edge to check the head deck of the cylinder block for flatness.

NOTE: Contact a Cummins® Authorized Distributor for a machining shop capable of repairing the ISZ cylinder block.

Newly machined surfaces must be flat within 0.51 mm [0.020 in] under a cylinder head.

Waves on the surface are acceptable as long as they are not more than 0.018 mm [0.0007 in] in height. The high and low points of the waves must not be any closer than 25.4 mm [1.0 in].

Machined surfaces must be within block height specifications.

Measure the liner seat depth.  From the cylinder block head deck to point (C).

Cylinder Block Seat Depth from Cylinder Block Head Deck

NOTE: If any of the liner seat depths are out of specification, the liner seat can be machined and shims installed. See the Repair section of this procedure.

If the liner seats require machining, use liner seat cutter, Part Number 3823569, to machine the liner seat to the proper depth.

Clean away any debris and shavings to be sure of a clean repair.

Cylinder liner shims are available in the following thicknesses.

Follow this procedure to salvage capscrew holes that are missing a portion of the threads.

Cracks that extend into the capscrew bosses or the coolant cavity, below the upper counterbore, can not be salvaged using this procedure.

Remove any burrs from the top deck surface of the cylinder block. A 12 inch, flat surface, mill file is effective for this step. Burr removal is necessary to obtain an accurate fixture location.

NOTE: The thread salvage kit is designed to be used with the cylinder liner removed. If the cylinder liner remains in the block, shims must be installed to both sides of the base equally to bridge the liner.

NOTE: On some engines, it will be necessary to use the spacer, Part Number 3376206, between the mounting base and drilling fixture.

Select two capscrew holes so the damaged capscrew hole is positioned approximately in the middle. Install the mounting plate assembly onto the capscrew holes using the appropriate spacers, four plain washers, and the existing cylinder head capscrews.

Use a heavy washer and the 5/8-18 x 3 inch hex head capscrew to attach the drilling fixture to the mounting plate assembly.

Slide the locating pin through the appropriate drilling fixture bushing hole until it rests in the damaged capscrew hole of the cylinder block.

Center the drilling fixture guide bar and bushing over the damaged capscrew hole.

Tighten the three capscrews to secure the fixture assembly.

Remove the locating pin.

Setting the stop collar is required only for repairs using drills.

Drills are used in some kits to allow the quick removal of waste material; however, care must be taken to make certain the depth of the repaired capscrew hole is not increased beyond specification.

The following steps will result in the drill stopping short of the original hole depth. The remaining material is then removed with the reamer.

Place a 0.76 mm [0.030 in] feeler gauge over the hole to be repaired.

Insert the drill through the drill bushing until its tip rests against the feeler gauge.

Place the thread insert to be installed between the drill bushing and the stop collar.

Move the stop collar down until it rests against the insert and tighten the stop collar.

Place the drill through the drill fixture bushing and let it rest over the top of the damaged capscrew hole.

Use a drill motor with a clutch and a maximum operating speed of 300 rpm. Use a suitable cutting fluid. Operate the drill motor until the stop collar contacts the drill bushing.

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

Remove the chips with a chip vacuum.

Place the reamer through the drill fixture bushing and let it rest over the top of the damaged capscrew hole.

Stop frequently, while reaming the hole, to clean the hole with the chip vacuum.

Use a drill motor with a clutch and a maximum operating speed of 300 rpm and a suitable cutting fluid. Operate the drill motor until the reamer reaches the bottom of the original capscrew hole.

The reamer will stop cutting when it reaches the bottom of the hole.

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

Remove the chips with a chip vacuum.

Install a ½ inch square drive socket on the end of the appropriate tap.

Keep the tap well lubricated during tapping.

Install the tap (4). Use a suitable tapping fluid and hand-tap to the bottom of the damaged capscrew hole.

Remove the tap.

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

Remove the chips with a chip vacuum.

Remove the mounting capscrews, spacers, four plain washers, and mounting plate assembly.

Thread the tap in and out of the newly-cut threads several times to verify the thread condition and clean debris from the threads.

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  Some solvents are flammable and toxic. Read the manufacturer’s instructions before using.

Check the capscrew hole for evidence of porosity and cracks.

Use a solvent-degreasing agent to clean the threads and flush any debris from the tapped hole.

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

Remove the solvent-degreasing agent from the hole with a chip vacuum.

Place the appropriate jam nut (1) on an appropriate capscrew.

Install the appropriate thread insert (2) onto the cylinder head mounting capscrew until it nears the bottom of the insert.

Rotate the jam nut (1) until it contacts the thread insert (2) to lock the insert and jam nut together.

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  Some solvents are flammable and toxic. Read the manufacturer’s instructions before using.

Use a solvent-degreasing agent to remove the preservative coating from the circumference of the thread insert.

Install the thread insert, jam nut, and capscrew into the newly-tapped hole. Make certain that the thread insert threads freely into the hole.

NOTE: For applications with a counterbore, measure the protrusion depth starting at the counterbore face, which is recessed into the hole.

Check for protrusion. Make certain the thread insert protrusion is 0 to 1.0 mm [0 to 0.040 in] above the cylinder block surface.

It is important to make certain the minimum required thread depth is maintained after thread repair.

If the insert protrusion exceeds 1 mm [0.040 in], the cylinder head capscrew can bottom out when tightened.

Record the amount the insert protrudes.

It is necessary to increase the depth of the original capscrew hole.

If the insert protrusion is correct, install the insert.

If the protrusion is not correct, record the measurement and adjust the bore depth.

Prior to increasing the capscrew hole depth, check the following:

1. Make certain the correct thread insert is being used. Two inserts are available. These inserts are identical, except for their length.
2. Make certain the insert used is the correct length.
3. Make certain the capscrew hole is threaded all the way to the bottom.
4. Make certain there are no burrs or other damage that would prevent the insert from threading to the bottom of the capscrew hole.

After checking the above listed items, if the thread insert protrusion still exceeds 1.0 mm [0.040 in], the depth of the original capscrew hole must be increased using the steps below. Do not increase the depth of the original capscrew hole more than 3.0 mm [0.120 in].

If the protrusion is within specification, the steps for increasing the depth of the hole can be skipped.

NOTE: The thread salvage kit is designed to be used with the cylinder liner removed. If the cylinder liner remains in the block, shims must be installed to both sides of the base equally to bridge the liner.

NOTE: On some engines, it will be necessary to use the spacer, Part Number 3376206, between the mounting base and drilling fixture.

Install the mounting plate assembly.

Do not tighten the fasteners.

Slide the drill through the drill bushing and into the threaded hole until it rests at the bottom of the hole.

Tighten all fasteners.

The drill must slide freely in the bushing and threaded hole, indicating that it is centered in the hole.

Do not increase the depth of the original capscrew hole more than 3.0 mm [0.120 in].

Slide the stop collar over the drill bit.

Subtract 0.50 mm [0.020 in] from the insert protrusion.

Select a feeler gauge equivalent to this value.

With the drill resting at the bottom of the hole, insert the feeler gauge between the stop collar and drill bushing.

Tighten the stop collar.

Use a drill motor with a clutch and a maximum operating speed of 300 rpm and a suitable cutting fluid. Operate the drill motor until the stop collar contacts the drill bushing.

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

Remove the chips with a chip vacuum.

It is not necessary to ream the hole prior to the second tapping.

Install a ½ inch square drive socket on the end of the appropriate tap.

Keep the tap well lubricated during the tapping operation.

Install the tap (4). Use a suitable tapping fluid to hand-tap to the bottom of the damaged capscrew hole.

Remove the tap.

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  Some solvents are flammable and toxic. Read the manufacturer’s instructions before using.

Check the capscrew hole for evidence of porosity and cracks.

Clean the threads, and flush any debris from the tapped hole using a solvent-degreasing agent.

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

Remove the chips and solvent-degreasing agent from the hole with a chip vacuum.

Install the thread insert on a cylinder head capscrew and lock it in place with a jam nut.

Temporarily install the thread insert and check the protrusion. Make certain that the protrusion is 0 to 1 mm [0 to 0.040 in] above the cylinder block surface.

After checking the above listed items, if the thread insert protrusion still exceeds 1.0 mm [0.040 in], the depth of the original capscrew hole must be increased. Follow the same procedure.

Prior to increasing the capscrew hole depth, check the following.

Do not increase the depth of the original capscrew hole more than 3.0 mm [0.120 in].

1. Make certain the correct thread insert is being used. Various inserts are available, and may appear identical except for their length.
2. Make certain the insert used is the correct length.
3. Make certain the capscrew hole is threaded all the way to the bottom.
4. Make certain there are no burrs or other damage that would prevent the insert from threading to the bottom of the capscrew hole.

Remove the insert.

After checking the above listed items, if the thread insert protrusion still exceeds 1.0 mm [0.040 in], the depth of the original capscrew hole must be increased using the steps above. Do not increase the depth of the original capscrew hole more than 3.0 mm [0.120 in].

Apply a light coat of primer, Part Number 3824715, to the thread insert and the threaded hole. Allow 3 to 5 minutes to dry.

Apply four beads of thread locking compound, Part Number 3824038, to the circumference of the thread insert.

Each bead must be 0.8 mm [0.03 in] wide down the entire length of the thread insert and the beads must be 90 degrees apart.

Install the thread insert until it is flush with the cylinder block surface or it bottoms in the hole.

Allow to dry for 3 hours.

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

Remove the capscrew and jam nut.

If necessary, file or machine the top of the thread insert so it is flush with the cylinder block surface.

Make certain that the inner diameter of the thread insert is free of burrs. Remove any file shavings or debris with the chip vacuum.

For applications where the thread insert is recessed into a counterbore, an end mill or a machine cutter will be necessary to remove the excess length of the insert and restore the alignment of the counterbore.

If the cylinder block is not going to be used immediately, apply a coating of preservative oil to prevent rust.

Cover the block to prevent dirt from sticking to the oil.

If replacing the cylinder block or using a previously stored cylinder block, make sure to clean any oil/rust preventative solvent from the cylinder bores, gasket sealing areas, and main bearing bores prior to use.

• Install the camshaft bushings. Refer to Procedure 001-010 in Section 1.
• Install the straight thread plugs. Refer to Procedure 017-011 in Section 17.
• Install the cup plugs. Refer to Procedure 017-002 in Section 17.
• Assemble the engine.  Use the procedures in Section AS (Engine Assembly).
• Operate the engine and check for proper operation.