C18 Generator Set STM00001-UP(SEBP4100 - 24) - Documentation Page 1 of 7

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Product:  GENERATOR SET 
Model:  C18 GENERATOR SET STM 
Configuration: C18 Generator Set STM00001-UP 

Testing and Adjusting

C13, C15, and C18 Generator Set Engines
Media Number -SENR9708-13 Publication Date -01/10/2013 Date Updated -16/10/2013

i02966520

Aftercooler - Test
SMCS - 1063-081

Table 1
Required Tools
Part Number Part Name Quantity
1U-5470 Engine Pressure Group 1
FT-1984 Aftercooler Testing Group 1
FT-1438 Aftercooler Gp (DYNAMOMETER TEST) 1

Visual Inspection
Inspect the following parts at each oil change:

• Air lines

• Hoses

• Gasket joints

Pressurized air can cause personal injury. When pressurized air is used
for cleaning, wear a protective face shield, protective clothing, and
protective shoes.

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Ensure that the constant torque hose clamps are tightened to the correct torque. Refer to Operation
and Maintenance Manual, "Hoses and Clamps - Inspect/Replace". Check the welded joints for cracks.
Ensure that the brackets are tightened in the correct positions. Ensure that the brackets are in good
condition. Use compressed air to clean any debris or any dust from the aftercooler core assembly.
Inspect the cooler core fins for the following conditions:

• Damage

• Debris

• Corrosion

Use a stainless steel brush to remove any corrosion. Ensure that you use soap and water.

Note: When parts of the air-to-air aftercooler system are repaired, a leak test is recommended. When
parts of the air-to-air aftercooler system are replaced, a leak test is recommended.

Inlet Manifold Pressure

Normal inlet manifold pressure with high exhaust temperature can be caused by blockage of the fins
of the aftercooler core. Clean the fins of the aftercooler core. Refer to "Visual Inspection" for the
cleaning procedure.

Low inlet manifold pressure and high exhaust manifold temperature can be caused by any of the
following conditions:

Plugged air cleaner - Clean the air cleaner or replace the air cleaner, as required. Refer to the
Operation and Maintenance Manual, "Engine Air Cleaner Element - Clean/Replace"or Operation and
Maintenance Manual, "Engine Air Cleaner Element (Dual Element) - Clean/Replace". Choose the
reference that fits the application.

Blockage in the air lines - Blockage in the air lines between the air cleaner and the turbocharger must
be removed.

Aftercooler core leakage - Aftercooler core leakage should be pressure tested. Refer to "Aftercooler
Core Leakage" topic for the testing procedure.

Leakage of the induction system - Any leakage from the pressure side of the induction system
should be repaired.

Inlet manifold leak - An inlet manifold leak can be caused by the following conditions: loose fittings
and plugs, missing fittings and plugs, damaged fittings and plugs and leaking inlet manifold gasket.

Aftercooler Core Leakage

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Illustration 1 g01489974

FT-1984 Aftercooler Testing Group

(1) Regulator and valve assembly

(2) Nipple

(3) Relief valve

(4) Tee

(5) Coupler

(6) Aftercooler

(7) Dust plug

(8) Dust plug

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(9) Chain

A low power problem in the engine can be the result of aftercooler leakage. Aftercooler system
leakage can result in the following problems:

• Low power

• Low boost pressure

• Black smoke

• High exhaust temperature

NOTICE

Remove all air leaks from the system to prevent engine damage. In
some operating conditions, the engine can pull a manifold vacuum for
short periods of time. A leak in the aftercooler or air lines can let dirt
and other foreign material into the engine and cause rapid wear and/or
damage to engine parts.

A large leak of the aftercooler core can often be found by making a visual inspection. To check for
smaller leaks, use the following procedure:

1. Disconnect the air pipes from the inlet and outlet side of the aftercooler core.

Dust plug chains must be installed to the aftercooler core or to the

radiator brackets to prevent possible injury while you are testing. Do
not stand in front of the dust plugs while you are testing.

2. Install couplers (5) on each side of the aftercooler core. Also, install dust plugs (7) and (8) .
These items are included with the FT-1984 Aftercooler Testing Group .

Note: Installation of additional hose clamps on the hump hoses is recommended in order to
prevent the hoses from bulging while the aftercooler core is being pressurized.

NOTICE

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Do not use more than 240 kPa (35 psi) of air pressure or damage to the
aftercooler core can be the result.

3. Install the regulator and valve assembly (1) on the outlet side of the aftercooler core assembly.
Also, attach the air supply.

4. Open the air valve and pressurize the aftercooler to 205 kPa (30 psi). Shut off the air supply.

5. Inspect all connection points for air leakage.

6. The aftercooler system's pressure should not drop more than 35 kPa (5 psi) in 15 seconds.

7. If the pressure drop is more than the specified amount, use a solution of soap and water to
check all areas for leakage. Look for air bubbles that will identify possible leaks. Replace the
aftercooler core, or repair the aftercooler core, as needed.

To help prevent personal injury when the tooling is removed, relieve all
pressure in the system slowly by using an air regulator and a valve
assembly.

8. After the testing, remove the FT-1984 Aftercooler Testing Group . Reconnect the air pipes on
both sides of the aftercooler core assembly.

Air System Restriction

Pressure measurements should be taken at the air inlet elbow and at the turbocharger outlet.

Use the differential pressure gauge of the 1U-5470 Engine Pressure Group . Use the following
procedure in order to measure the restriction of the aftercooler:

1. Connect the vacuum port of the differential pressure gauge to a port in the air inlet elbow.

2. Connect the pressure port of the differential pressure gauge to a port in the turbocharger outlet.

3. Record the value.

The air lines and the cooler core must be inspected for internal restriction when both of the following
conditions are met:

• Air flow is at a maximum level.

• Total air pressure drop of the charged system exceeds 13.5 kPa (4 in Hg).

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If a restriction is discovered, proceed with the following tasks, as required:

• Clean

• Repair

• Replacement

Turbocharger Failure

Personal injury can result from air pressure.

Personal injury can result without following proper procedure. When

using pressure air, wear a protective face shield and protective clothing.

Maximum air pressure at the nozzle must be less than 205 kPa (30 psi)
for cleaning purposes.

If a turbocharger failure occurs, remove the air-to-air aftercooler core. Internally flush the air-to-air
aftercooler core with a solvent that removes oil and other foreign substances. Shake the air-to-air
aftercooler core in order to eliminate any trapped debris. Wash the aftercooler with hot, soapy water.
Thoroughly rinse the aftercooler with clean water and blow dry the aftercooler with compressed air.
Blow dry the assembly in the reverse direction of normal air flow. To make sure that the whole
system is clean, carefully inspect the system.

NOTICE

Do not use caustic cleaners to clean the air-to-air aftercooler core.

Caustic cleaners will attack the internal metals of the core and cause
leakage.

Dynamometer Test
In hot ambient temperatures, dynamometer tests for models with an air-to-air aftercooler can add a
greater heat load to the jacket water cooling system. Therefore, the jacket water cooling system's
temperature must be monitored. The following measurements may also need a power correction
factor:

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• Inlet air temperature

• Fuel API rating

• Fuel temperature

• Barometric pressure

With dynamometer tests for engines, use the FT-1438 Aftercooler Gp (DYNAMOMETER TEST).
This tool provides a water cooled aftercooler in order to control the inlet air temperature to 43 °C (110
°F).

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