DRUM 8P1181 - Caterpillar

Diagnostic Procedures
Note: Blow-by and oil carry-over is a measure of breather performance and not conclusively related to engine condition. Some engines have high blow-by and oil carry over when compared to similar engines, with no detrimental impact on engine life and performance.
Ensure that the correct specification of lubricating oil is used. Refer to Operation and Maintenance Manual for more information.
Ensure that the engine oil level is correct. Refer to Operation and Maintenance Manual for more information.
Many anomalies can be attributed to the measurement process. Allow for 10 to 20 percent error in the readings.
Identify any additional blow-by generators that may have been installed to the engine. For example compressor pumps. Establish the contribution from that source.
Extreme ambient can cause measurement anomalies. Sub zero temperatures can cause false readings.
Ensure that the application has completed at least 50 hours (preferably one 100 hours) of running including high loads.
Verify that the breather vent drip performance meets the characteristic specified for the breather type.
Ensure that the air system has maintained adequate control of dirt ingress.
Ensure that any serviceable breather items have been maintained.
Contact the Dealer Solution Network (DSN).
Define the reason for raising a concern over breather performance. For example, excessive drips, vapor, odor, loss of engine performance and increased oil consumption.
Provide oil samples, crankcase pressure measurements, blow-by measurements, and drip rate data.Blow-by Rates
Blow-by rates will generally fall between the valves shown in table 1. The number represent Full Load Rated Speed (FLRS) values as measured on a test bed to TP 2/11 (Blow-by Measurement).
Table 1
Sales Model Lower Blow-by Level Higher Blow-by Level
3024C 40 L/min (85 FT3/HR) 90 L/min (191 FT3/HR)
C2.2 40 L/min (85 FT3/HR) 90 L/min (191 FT3/HR)
C3.3 60 L/min (127 FT3/HR) 90 L/min (191 FT3/HR)
3054C 80 L/min (170 FT3/HR) 120 L/min (254 FT3/HR)
3056E 120 L/min (254 FT3/HR) 180 L/min (381 FT3/HR)
C4.4 90 L/min (191 FT3/HR) 120 L/min (254 FT3/HR)
C6.6 120 L/min (254 FT3/HR) 180 L/min (381 FT3/HR)
C7.1 (Mechanical)
C7.1 Tier 4 Interim and Tier 4 Final 120 L/min (254 FT3/HR) 180 L/min (381 FT3/HR)
180 L/min (381 FT3/HR) 200 L/min (424 FT3/HR) Test Procedure for Blow-by Checks
Table 2
Required Tools
Tool Part Number Part Description Qty
A 8T-2700 Blow-by/Air Flow Indicator 1
Illustration 1 g02562956
Typical example
(1) Actual button
(2) L/min buttonThis procedure covers the method for measuring blow-by on applications.Blow-by should be checked at Low Idle, High Idle, and Maximum Stall or double stall.Note: The equipment must be calibrated and cleaned before and after use.
Start the engine. Refer to Operation and Maintenance Manual for the correct procedure. Operate the engine to ensure that the engine has reached normal operating temperature.
Install Tooling (A) to the breather hose.
Set Tooling (A) to liters per minute (L/min) (2).
Set Tooling (A) to "Actual" (1). Setting Tooling (A) to "Actual" measures the mean value. Ensure blow-by meter is reading continuously.
Set the engine to run at low idle until blow-by reading is stable. The reading should not fluctuate by more than plus or minus 4 L/min. Record this