C27 Generator Set Engines Caterpillar

A general visual inspection should be made to the air inlet and exhaust system. Make sure that there are no signs of leaks in the system.

Table 1

Required Tools
Part Number	Part Name	Quantity
1U-5470 or 198-4240	Engine Pressure Group or Digital Pressure Indicator	1

Illustration 1	g00295554
1U-5470 Engine Pressure Group

Air Inlet Restriction

There will be a reduction in the performance of the engine if there is a restriction in the air inlet system.

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Illustration 2	g02148248
Right side view of the engine (1) Air filter restriction indicator (2) Air cleaner cover assembly

1. In order to check for a plugged air filter, observe air filter restriction indicator (1). Refer to Illustration 2. Replace the filter if the air filter restriction indicator indicates that the restriction pressure is above the specified limit. Refer to the Operation and Maintenance Manual.
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   Illustration 3	g02148273

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   Illustration 4	g02148337
   (3) Hoses (4) Air cleaner cover assembly (5) Tube (6) Turbocharger

2. Inspect the engine air cleaner inlet, tubes (5), and hoses (3) in order to ensure that the passageway is not blocked or collapsed. Refer to Illustration 3 and Illustration 4.

3. Check for dirt contamination on the clean side of the engine air cleaner element. If any dirt contamination is observed, contaminants are flowing past the engine air cleaner element and/or the seal for the engine air cleaner element.
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   Hot engine components can cause injury from burns. Before performing maintenance on the engine, allow the engine and the components to cool.

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   Making contact with a running engine can cause burns from hot parts and can cause injury from rotating parts. When working on an engine that is running, avoid contact with hot parts and rotating parts.

4. Use the differential pressure gauge of the 1U-5470 Engine Pressure Group.

   1. Connect the vacuum port of the differential pressure gauge to the test location. The test location may be located anywhere along the air inlet piping after the air cleaner but before the turbocharger.

   2. Leave the pressure port of the differential pressure gauge open to the atmosphere.

   3. Start the engine. Run the engine in the no-load condition at high idle.

   4. Record the value.

   5. Multiply the value from Step 4.d by 1.8.

   6. Compare the result from Step 4.e to the appropriate values that follow.

The air flow through a used engine air cleaner may have a restriction. The air flow through a plugged engine air cleaner will be restricted to some magnitude. In either case, the restriction must not be more than the following amount:

Maximum restriction ... 7.6 kPa (30.54 inch of H₂O)

The air flow through a new engine air cleaner element must not have a restriction of more than the following amount:

Maximum restriction ... 3.7 kPa (14.87 inch of H₂O)

Exhaust Restriction

There will be a reduction in the performance of the engine if there is a restriction in the exhaust system.

Note: Excessive idling can cause the muffler, the catalytic converter/muffler. A plugged muffler, a plugged catalytic converter/muffler can lead to an increase in exhaust back pressure. Operating the engine in cold conditions may cause the muffler, the catalytic converter/muffler to plug. One indication of a plugged muffler, catalytic converter is poor engine response.

Back pressure is the difference in the pressure between the exhaust at the outlet elbow and the atmospheric air.

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Hot engine components can cause injury from burns. Before performing maintenance on the engine, allow the engine and the components to cool.

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Making contact with a running engine can cause burns from hot parts and can cause injury from rotating parts. When working on an engine that is running, avoid contact with hot parts and rotating parts.

1. Connect the pressure port of the differential pressure gauge to the test location. The test location can be located anywhere along the exhaust piping after the turbocharger but before the muffler.

2. Leave the vacuum port of the differential pressure gauge open to the atmosphere.

3. Start the engine. Run the engine in the no-load condition at high idle.

4. Record the value.

5. Multiply the value from Step 4 by 1.8.

6. Compare the result from Step 5 to the value that follows.

Back pressure from the exhaust must not be more than the following amount:

Maximum back pressure ... 6.8 kPa (27.33 inch of H₂O)