Using the 8T-2700 Blowby/Air Flow Indicator{0781, 0785, 1317} Caterpillar


Using the 8T-2700 Blowby/Air Flow Indicator{0781, 0785, 1317}

Usage:

769C 01X

Information for equipment:


BASIC ENGINE
CYLINDER BLOCK GP

Setup and Operation of the 368-8645 Tool Kit (CRANKCASE PRESSURE){1317} Setup and Operation of the 368-8645 Tool Kit (CRANKCASE PRESSURE){1317}
Using the 8T-2700 Blowby/Air Flow Indicator{0781, 0785, 1317} Using the 8T-2700 Blowby/Air Flow Indicator{0781, 0785, 1317}
420-7630 Main Bearing Cap Lifting Device{0599, 0629, 0632, 0701, 1201, 1203, 1230} 420-7630 Main Bearing Cap Lifting Device{0599, 0629, 0632, 0701, 1201, 1203, 1230}
Using the 242-3980 Piston Groove Gauge on 3500A and B Engines with Monotherm Pistons using the 329-2630 and 329-2631 Piston Groove Gauges on 3500B Engines with Monotherm Pistons{0374, 0599, 0700, 0701, 0705} Using the 242-3980 Piston Groove Gauge on 3500A and B Engines with Monotherm Pistons using the 329-2630 and 329-2631 Piston Groove Gauges on 3500B Engines with Monotherm Pistons{0374, 0599, 0700, 0701, 0705}


Caterpillar Products: All

Introduction

European Union Compliant, CE Marked

Important Safety Information




Illustration 1g02139237

Think Safety

Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly.

Improper operation, lubrication, maintenance, or repair of this product can be dangerous and could result in injury or death.

Do not operate or perform any lubrication, maintenance, or repair on this product until you have read and understood the operation, lubrication, maintenance, and repair information.

Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.

The hazards are identified by the Safety Alert Symbol and followed by a Signal Word such as "DANGER","WARNING", or "CAUTION". The Safety Alert "WARNING" label is shown below.

A non-exhaustive list of operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are therefore, not all inclusive. If a tool, procedure, work method, or operating technique that is not recommended by Caterpillar is used, the operator must be sure that the procedures are safe. The operator must also be sure that the product will not be damaged or made unsafe by any unspecified procedures.

The information, specifications, and illustrations in this publication are based on information that was available at the time that the publication was written. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete and most current information before you start any job.

When replacement parts are required for this product, Caterpillar recommends using Cat replacement parts or parts with equivalent specifications including, but not limited to physical dimensions, type, strength, and material.

Literature Information

This manual contains safety information, operation instructions and maintenance information and should be stored with the tool group.

Some photographs or illustrations in this publication may show details that can be different from your service tool. Guards and covers might have been removed for illustrative purposes.

Continuing improvement and advancement of product design might have caused changes to your service tool, which are not included in this publication.

Whenever a question arises regarding your service tool or this publication, consult Dealer Service Tools (DST) for the latest available information.

Safety Section

The Safety Section lists basic safety precautions.

Read and understand the basic precautions listed in the Safety Section before operating or performing maintenance and repair on this service tool.

General Information Section

The General Information Section describes tooling functions and features. This section provides useful information on individual parts, additional tooling, and resources.

Operation Section

The Operation Section is a reference for the new operator and a refresher for the experienced operator.

Photographs and illustrations guide the operator through correct procedures for using the tool group.

Operating techniques outlined in this publication are basic. Skill and techniques develop as the operator gains knowledge of the service tool and tool capabilities.

Maintenance Section

The Maintenance Section is a guide to tool inspection, cleaning, storage, and tool disposal

Safety Section

Safety Icon Nomenclature

Personal Protection/Important Information




Illustration 2g02166423

Personal Protection/Important Information

Hazard Avoidance


Crushing Hazard (foot)


Crushing Hazard (hand)


Pinch Point


Working Load Limit (WLL) mark - Do not use lifting device unless load identification (WLL) markings are legible.


Safety Alert - Do not use C-Frame lifting device for anything other than the intended purpose.

Introduction

The 8T-2700 Blowby/Air Flow Indicator has a digital readout that is capable of displaying either volume or air flow. The blowby/air flow indicator displays Metric units. The blowby/airflow indicator also displays US Customary units.

The blowby/air flow indicator can measure the exhaust gas that escapes from the crankcase. The gas that escapes is commonly known as blowby.

Measuring the blowby helps the technician assess the condition of the cylinder, which can be very helpful in determining when engine repair is needed. The amount of blowby can be displayed in liters per minute or in cubic feet per hour.

The blowby/air flow indicator can measure the airflow that passes through the radiator core. Measuring the airflow helps the technician locate areas in the radiator core that have become restricted. The rate of airflow can be displayed in meters per minute or in feet per minute.

Adaptability




Illustration 3g03021316

The 8T-2700 Blowby/Air Flow Indicator is adaptable to all Cat engines. Measurements of 3600 Series Engines also require a 1U-8860 Blowby Pickup Group . The blowby/airflow indicator is adaptable to all radiators that have straight cores.

8T-2700 Blowby/Air Flow Indicator




Illustration 4g03021496

  1. 6V-7145 Case with Decal, SEES5692

  1. The vinyl hose has an ID of 19.05 mm (0.75 inch). The wall thickness of the vinyl hose is 3 mm (0.125 inch). The length of the vinyl hose is 1524 mm (5 ft). The nipple is 12.7 mm (0.50 inch) male pipe by 19.05 mm (0.75 inch) with a 12.7 mm (0.5000 inch) hose clamp.

  1. The bushing is 25.4 mm (1.0 inch) by 12.7 mm (0.50 inch).

  1. The hose clamps have an operating range of 19.05 mm (0.75 inch) to 50.8 mm (2.0 inch). Two hose clamps are included.

  1. 8T-2685 Blowby Pickup with Decal SEES5694

  1. 8T-5297 Cable Assembly

  1. The bushing is 19.05 mm (0.75 inch) by 12.7 mm (0.50 inch).

  1. The bushing is 32 mm (1.25 inch) by 12.7 mm (0.50 inch).

  1. 8T-2701 Blowby Indicator Assembly

  1. The bushing is 38.1 (1.5 inch) by 12.7 mm (0.50 inch).

  1. The 8T-2701 Blowby Indicator Assembly comes with the following 4 vinyl hoses.

    1. The first vinyl hose has an ID of 22 mm (0.875 inch). The wall thickness is 3 mm (0.125 inch). The length of the hose is 102 mm (4 inch).

    1. The second hose has an ID of 6.35 mm (0.25 inch). The wall thickness is 5 mm (0.185 inch). The length of the hose is 102 mm (4 inch).

    1. The third hose has an ID of 38.1 mm (1.50 inch). The wall thickness is 5 mm (0.185 inch). The length of the hose is 102 mm (4 inch) long.

    1. The fourth hose has an ID of 50.8 mm (2.0 inch). The wall thickness is 5 mm (0.185 inch). The length of the hose is 102 mm (4 inch).

  1. The length of the PVC pipe is 305 mm (12 inch). The diameter of the PVC pipe is 12.7 mm (0.5 inch). There is also a PVC Schedule 40 Bushing.

The optional items that are available are listed below:

  • The 5P-7366 Power Cable allows you to connect the indicator to an 11 to 40V DC machine battery.

  • The 8T-5268 Converter operates on either 110V AC at 50 Hz or 230V AC at 60 Hz. The converter supplies the diagnostic service tools with 11 to 20V DC at a maximum current of 0.3 amperes.

  • The 6V-2198 Cable has a length of 5500 mm (18 ft).

Features of the 8T-2700 Blowby/Air Flow Indicator

Digital Readout - A Liquid Crystal Display (LCD) provides a 4.5 digit display of the measurement value. Arrows on the digital display indicate the active function.

Storage Memory - Three separate storage memories record the minimum, the maximum, and the different values of the measurements that are being taken. These values may be displayed at any time.

Hold Function - The display may be held constant for any length of time.

Touch Pad - A touch pad controls the functions of the indicator.

Power - The 8T-2701 Blowby Indicator Assembly is powered with an internal 9V battery. External power that is 11 to 40V DC can be used when the internal battery is low. An 8T-5268 Converter is also available to power the indicator.

A power-saving feature turns the display off if the probe is not used for 15 minutes. This auto turn-off feature may be disabled.

Low Battery Voltage Indicator - When the internal battery or external power is less than 6V, LO BAT will appear on the display. The blowby/airflow indicator will remain accurate until the voltage drops to 5.5V.

Once LO BAT appears on the display, 2 hours of continuous operation will remain, or 5 hours of intermittent operation will remain.

Specifications

Power:

Internal ... standard 9V battery
External ... 11 to 40V DC at .007 Ampere

Measuring Range:

L/min ... 8 to 472
Ft?/hr ... 18 to 1000
M/min ... 43 to 2390
Ft/min ... 141 to 7843

Accuracy - System accuracy ±5%

Resolution - Blowby: 1 L/min (1 Ft?/min), Air Flow: 1 M/min (1 Ft/min)

Display Update Rate and Data Measuring Rate

Normal Rate - Data measured 2 1/2 times per second. The LCD is updated at one second intervals.

Medium Rate - Data measured 2 1/2 times per second. The LCD is updated at five second intervals.

Slow Rate - Data measured 2 1/2 times per second. The LCD is updated at 10 second intervals.

Operating Temperature

8T-2701 Blowby Indicator Assembly ... -18 to +60°C (0 to 140°F)
8T-2685 Blowby Pickup ... -18 to +121°C (0 to +250°F)

Storage Temperature

8T-2701 Blowby Indicator Assembly ... -40 to +100°C (-40 to +212°F)
8T-2685 Blowby Pickup ... -40 to +232°C (-40 to +450°F)

Battery Life (Alkaline Battery)

Continuous use ... 30 hours (nominal)
Intermittent use ... up to 90 hours

Size

8T-2700 Blowby/Air Flow Indicator ... 432 mm x 330 mm x 114 mm (17 inch x 13 inch x 4.5 inch)
8T-2701 Blowby Indicator Assembly ... 190 mm x 112 mm x 40 mm (7.5 inch x 4.4 inch x 1.6 inch)

Weight

8T-2700 Blowby/Air Flow Indicator ... 4.1 kg (9.12 lb)
8T-2701 Blowby Indicator Assembly ... 0.6 kg (1.25 lb)
8T-2685 Blowby Pickup ... 0.2 kg (0.5 lb)

Connections to the 8T-2701 Blowby Air Flow Indicator




Illustration 5g03021517

(1) Connector for external power source

(2) Connector for 8T-2685 Blowby Pickup

Connector for the External Power Source - The connection for the external power source is 11 to 40V DC. This connection is not required if a good 9V battery is installed in the indicator.

Use the optional 5P-7366 Power Cable to connect to the machine battery.

The optional 8T-5268 Converter connects at location (1) for 110/230 VAC.

Connector for Blowby Pickup - Install 8T-2685 Blowby Pickup or the 1U-8860 Blowby Pickup at location (2). Use the 8T-5297 Cable Assembly . The 6V-2198 Cable may be used if a longer cable is required.

Blowby/Air Flow Indicators




Illustration 6g03021526

  1. HOLD -The value on the display is being held and the value will not change even if the values change.

  1. DIGITAL DISPLAY -Liquid crystal display (LCD)

    Note: An arrow will appear on the display next to the label to indicate the following functions.

  1. UNDER -The flow rate is under the range of the indicator. The display will be blank.

  1. L/MIN -The blowby value in liters per minute.

  1. NORM -The display is being updated at the normal rate of one second intervals.

  1. Ft?/HR- The blowby value in cubic feet per hour.

  1. MED -The display is being updated at the medium rate of five second intervals.

  1. M/MIN -The air flow displays in meters per minute.

  1. SLOW -The display is being updated at the rate of 10 second intervals.

  1. FT/MIN -The air flow displays in feet per minute.

  1. MIN -The minimum value that is recorded during the test.

  1. ACTUAL -The current actual amount of flow.

  1. MAX -The maximum value that is recorded during the test.

  1. DIFF INDICATOR -The difference in the values that are recorded for minimum and maximum.

Controls on the Blowby/Air Flow Indicator




Illustration 7g03021556

  1. L/MIN -After pressing, the display will indicate the amount of blowby in liters per minute. An arrow will appear on the display next to L/MIN.

  1. Ft?/HR -After pressing, the display will indicate the amount of blowby in cubic feet per hour. An arrow will appear on the display next to Ft?/HR.

  1. M/MIN -After pressing, the display will indicate the amount of air flow in meters per minute. An arrow will appear on the display next to M/MIN.

  1. Ft/MIN -After pressing, the display will indicate the amount of air flow in feet per minute. An arrow will appear on the display next to Ft/MIN.

  1. MIN -This button displays the minimum value that is recorded during the test once the CLEAR button is initially pressed. An arrow will appear on the display above MIN.

  1. MAX -This button displays the maximum value that is recorded during the test once the CLEAR button is initially pressed. An arrow will appear on the display above MAX.

  1. DIFF -After pressing, the display will indicate the difference between the minimum value and the maximum value, once the CLEAR button is initially pressed. An arrow will appear on the display above DIFF. This function is only for blowby.

  1. ACTUAL -After pressing, this will display the current actual value. An arrow will appear on the display above ACTUAL.

  1. CLEAR -After pressing, the memories will be cleared for the MIN value, the MAX value, and the DIFF value. The value that is currently displayed will be entered into the memory for the MIN and the MAX when the CLEAR button is pressed.

  1. SLOW RATE -This feature causes the display to be updated in 10 second increments. An arrow will appear on the display next to SLOW. Use SLOW RATE to slow the display reading when the display is changing rapidly.

  1. MED RATE -This feature causes the display to be updated in 5 second increments. An arrow will appear on the display next to MED. MED RATE may be used to slow the display reading when the display is changing rapidly.

  1. NORM RATE -This feature causes the display to be updated in 1 second increments. An arrow will appear on the display next to NORM.

  1. HOLD -When this button is pressed, the MIN, MAX, DIFF or ACTUAL readings will not change until the HOLD and CLEAR buttons are pressed or until the indicator is turned off.

  1. HOLD CLEAR -If the reading on the display is being held, this button will allow the reading to be updated to the current value. The arrow next to HOLD will disappear when the HOLD button is pressed.

  1. ON -This button turns the indicator on.

  1. OFF -This button turns the indicator off. No memories are retained.

Powering the Blowby/Air Flow Indicator

The following three methods are used to power the indicator:

  • Internal 9V battery for portable use

  • External 11 to 40V DC from machine battery

  • 8T-5268 Converter from an AC power source

Operation from the Internal Battery

The blowby/airflow indicator is normally operated from the internal 9V battery. If the battery is installed and the battery is in good condition, the blowby/airflow indicator will operate whenever the ON button is pressed. When the battery voltage drops to 6V, and approximately two hours of battery life remain, the words LO BAT will appear on the display. The internal battery should be changed by using the following procedure:

Note: The battery must be changed within two hours after LO BAT appears on the display, or inaccurate results will be obtained.

Replacing the Internal Battery




Illustration 8g03021576

  1. Remove six screws (1) from the rear cover. Remove cover (2) .



    Illustration 9g03021736

  1. To remove battery (3), pull upward on the battery and remove the battery from the holder.

  1. Install a new 9V battery in the battery holder.

    Note: Be sure that the positive (+) terminal on the battery is on the positive (+) terminal in the holder.

  1. Install the rear cover (2) and six screws (1) .

External 11 to 40 Volt DC Operation from Machine Battery




Illustration 10g03021759

  1. Use 5P-7366 Power Cable . This cable is the same 6M (20 ft) power cable that is used with the 9U-7400 Multitach Tool Group .

  1. Connect the power cable to the connector (4) on top of the blowby/airflow indicator.

    Note: Always connect one of the clips to the frame of the machine. Connect the other clip to the positive (+) terminal on the battery. The connector is not polarized. Either clip may be connected to the positive (+) terminal on the battery or to the machine frame.

  1. The machine might be equipped with a disconnect switch. The disconnect switch must be turned to the ON position in order to power the blowby/airflow indicator. Once power has been supplied, the blowby/airflow indicator will operate whenever the ON button is pressed.

Fuse Replacement




Illustration 11g03026597

Use the following procedure to check and replace these fuses if the indicator fails to operate.

  1. Remove six screws (1) from the rear cover. Remove cover (2) from the indicator.



    Illustration 12g03026605

  1. Locate two fuses (3) on the printed circuit board. The fuses are located directly behind the connector for the external power source. There is no need to remove the fuses from the holders for the check.

  1. Use a 6V-7070 Digital Multimeter to check both fuses. Put the multimeter on the 200 Ohm scale. Place a probe on each end of the same fuse.

    Note: A good fuse will measure less than 1 ohm resistance. A damaged fuse will measure infinite ohm OL on the multimeter display. Replace the damaged fuse with an 8K-4644 Fuse .

External AC Power Operation from the 8T-5268 Converter

  1. Set the voltage selector switch on the 8T-5268 Converter for the correct AC voltage, either 120V or 230V. The voltage selector switch is located on the back of the converter.

  1. Plug the connector on the 8T-5268 Converter into the connector for the external power source on the blowby/airflow indicator. Plug the converter into an AC outlet. For operation outside the USA, an AC adapter may be required.

  1. Once the power has been supplied, the blowby/airflow indicator will operate whenever the ON button is pressed.

Operating Instructions

Checking the Operation of the Blowby/ Air Flow Indicator

The following procedure may be used to check the operation of the 8T-2701 Blowby Indicator Assembly , the 8T-2685 Blowby Pickup , or the 1U-8860 Blowby Pickup . This procedure is designed to test the operation of the systems only. This test is not intended to check for accuracy.

The components for this test are the blowby/airflow indicator, the 8T-5297 Cable , and the blowby pickup. Perform the following steps:

  1. In order to power the 8T-2701 Blowby Indicator Assembly , refer to "Powering the Blowby/Air Flow Indicator". Do not connect the pickup to the blowby/airflow indicator.

  1. When you press the ON button, the letters OF should flash on the display. This display indicates that a pickup has not been installed or that the cable is broken.

  1. Use the 8T-5297 Cable to connect the 8T-2685 Blowby Pickup to the blowby/airflow indicator. The flashing should stop and the display should read 0.

  1. Press the following buttons in order to ensure that an arrow appears on the display at the labels with the same name as the button.

  1. Press the FT/MIN, ACTUAL, and the NORM RATE buttons.

  1. Blow air into the pickup in the direction of the arrow on the pickup. Observe the reading on the display. The display should show approximately 300 to 900 FT/MIN.

  1. Press the M/MIN button. The arrow should point to M/MIN. Blow air into the pickup. The display should show approximately 100 to 400 M/MIN.

  1. Press the FT?/HR button. The arrow should point to FT?/HR. Blow air into the pickup. The display should show approximately 100 to 400 FT?/HR.

  1. Press the L/MIN button. The arrow should point to L/MIN. Blow air into the pickup again. The display should show approximately 10 to 80 L/MIN.

  1. Press the MAX button. The arrow should point to MAX. A number should be on the display. The maximum value should be on the display. The maximum value should be 900 during the last four tests. Remember this number for the next test.

  1. Press the MIN button. The arrow should point to MIN. The display should read 0.

  1. Press the DIFF button. The arrow should point to DIFF. The display should read the difference between MIN and MAX. The value for the DIFF should equal the value for the MAX.

  1. Press the CLEAR button and look at the values in MIN, MAX and DIFF. The values should be 0.

  1. Blow air into the pickup continuously after pressing the MIN button in order to check the MIN function. The display will read 0. While you are still blowing air, press the CLEAR button. A value will appear on the display. This value is the minimum value that appeared. When you stop blowing air into the pickup, the display will go to 0. This value is the new minimum value.

  1. In order to check the HOLD function, repeat Step 14. While blowing air into the pickup, press the HOLD button after pressing the CLEAR button. The minimum value should stay on the display and an arrow should appear next to HOLD. Press the HOLD button and the CLEAR button. The number on the display should go to 0. The arrow next to HOLD should disappear.

  1. In order to check the RATE buttons, press the FT/MIN button and the ACTUAL button. The arrow for the NORM RATE button should indicate that the NORM RATE button has been depressed. Vary the force of the air into the pickup. The reading on the display should change accordingly. The reading should change every second. Press the MED RATE button. The reading should change in five second intervals. Press the SLOW RATE button. The reading should change in 10 second intervals.

  1. Press the OFF button. The display should be blank. This completes the test of the blowby/Air Flow Indicator.

Test Procedure

Hookup for Checking Blowby




Illustration 13g03026616

  1. Attach the 1.5 M (5 ft) hose to the most convenient location on the crankcase breather output tube or the breather hose. Connect appropriate sized bushing (3) and hose (2) to the crankcase breather. Secure hose with clamps (1) .



    Illustration 14g03026638

  1. Attach 8T-2685 Blowby Pickup (5) to the hose by sliding the pickup into hose (4) .

    Note: Install pickup (5) with arrow (6) in the direction of the air flow.

  1. Attach 8T-5297 Cable to 8T-2685 Blowby Pickup and 8T-2701 Blowby Indicator Assembly .

Measuring Blowby

Note: The 8T-2685 Blowby Pickup is sensitive to noise or movement of air. In order to prevent inaccurate readings, keep the pickup away from the engine fan and any movement of air past the end of the pickup.

  1. Start and run the engine until normal operating temperature is reached.

  1. Press the ON button.

    1. Press the ACTUAL button. An arrow must appear above ACTUAL on the display.

    1. Select L/MIN or FT?/HR and press the button. An arrow must appear next to the selection.

    1. Press the NORM RATE button. An arrow must appear next to the selection.

  1. Run the engine at high idle. The value of the blowby will be displayed. The display will change whenever the amount of blowby changes.

  1. Press the MED RATE or SLOW RATE button if the display is changing too fast.

    1. After you test the minimum blowby, test the maximum blowby and record the difference between the two. Press the buttons in order to recall the MIN and MAX or the DIFF between the two readings.

    1. Press the CLEAR button in order to retest the MIN and MAX.

    1. To retain the MIN, MAX, DIFF or ACTUAL value on the display, press the HOLD button.

      Note: Do not press the HOLD button until the check has been completed. The readings will not change after the HOLD button is pressed. The memory will retain the values until the HOLD CLEAR button is pressed or until the blowby/airflow indicator is turned off.

Analyzing Results

Note: Do not use the data alone to determine if the engine should be overhauled. The obtained data from the blowby/airflow indicator should only be used for additional information. Other indicators such as high oil consumption, low power, hard starting, and excessive fuel consumption must be considered.

The data from the blowby/airflow indicator should be used in order to establish a trend for the engine. It is important not to make a decision whether or not to repair an engine, based on the results of a single blowby test.

After a new engine is used for a short time, the blowby can decrease as the rings are seated. New engines should be checked for blowby during all maintenance checks. As the piston rings and cylinder walls wear, the blowby will gradually increase. Other sources of blowby can be worn valve guides or leaking turbocharger seals.

The blowby on a worn engine may be two times or more than the blowby of a new engine and may indicate the need for an overhaul.

An engine that has been overhauled can have a high rate of blowby due to several factors: improperly seated rings, worn parts which were not changed, and worn valve guides.

By keeping a record of the results, a gradual increase in the amount of the blowby will be noted until the amount of blowby has become excessive. Any sudden increase in blowby could indicate a broken piston ring.

Always check the blowby by the same method for better comparison of future tests. Read the rate of blowby at full engine RPM, either at no load or at full load. The blowby could vary as much as 100 percent under a no load condition to a full load condition. Use the highest reading for the actual blowby value.

The blowby meter is sensitive to engine noise at high frequencies. When you are making blowby measurements, keep the blowby pickup as far away from the engine as possible. Do NOT put the pickup near the turbocharger or fan blades, as this can cause a reading error.

Note: It is normal for ACERT Engines to have twice the blowby in comparison to engines that are not equipped with ACERT technology. Blowby rates for ACERT Engines will be released at a later date.

Checking Air Flow Through the Radiator Core

The 8T-2700 Blowby/Air Flow Indicator can help in analyzing engine overheating problems. The following items can cause overheating:

  • Overload

  • Low fan speed

  • Improper shroud

  • Plugged radiator core

Plugging of the radiator core is the most common cause of poor air flow. The blowby/airflow indicator measures the air flow through the radiator core. The blowby/airflow indicator also helps pinpoint the exact location of a restriction in the radiator core.

The blowby/airflow indicator is most effective with blower fans. Suction fans tend to average the air flow across the core. A radiator core that has plugged areas will have a reduction of air flow.

The air that flows across the radiator core may not be consistent. The items that follow affect the air that flows across the radiator core:

  • Air swirl

  • Guards

  • Braces

  • Position of engine mounted components




Illustration 15g03033076

The air flow rises sharply at the inner tip (2) of the fan blade. The air flow gradually increases to a maximum at the outer tip (1).




Illustration 16g03033096

The flow of air is lowest at the center of the fan hub (5). Maximum air flow is found in the area of the fan blades (4) .

The flow of the air in the corners of the radiator core (3) are generally less than the flow of the air in area (4). However, the flow of the air in the corners of the radiator core (3) are higher than the flow of the air in area (5) .

Turn off the engine and place a light behind the radiator core. Inspect the radiator core for plugged areas. The fan guards may limit the visibility of the inspection.

If area (4) of the radiator core is plugged, the rest of the radiator core could be plugged. The light may show through area (4) and the radiator core can still be plugged in area (3). This is due to air velocity that has not been high enough to blow material through the core.

Test Procedure to Measure Air Flow




Illustration 17g03033302

  1. Attach PVC pipe (6) to 8T-2685 Blowby Pickup (7) .

    Note: Ensure that the air flow is in the direction of arrow (8). The end of pipe (6) should be against the radiator core during the test.




    Illustration 18g03033336

  1. Connect 8T-2685 Blowby Pickup (7) to 8T-2701 Blowby Indicator Assembly (10) with 8T-5297 Cable (9) .

  1. Press the ON button. Select the following functions with the buttons on the front panel of the blowby/airflow indicator.

    1. Press the ACTUAL button. An arrow must appear above ACTUAL on the display.

    1. Select M/MIN or FT/MIN and press the button on the blowby/airflow indicator. An arrow must appear on the display next to the selection made.

    1. Press the NORM RATE button. An arrow must appear next to NORM on the display.

  1. Start the engine and run the engine at high idle. Check the air flow by placing the PVC pipe against the radiator core.

    Note: Air flow below 43 M/MIN (141 FT/MIN) will read 0 on the blowby/airflow indicator.

  1. Check the air flow by using circular patterns at an equal distance from the fan hub. The air flow can be decreased at some point in any circular pattern.

A blocked radiator core or a restricted radiator core will cause a decrease in the air flow.

Disabling the Auto Turn-off Feature (If Equipped)

The blowby airflow indicator will turn off automatically if the indicator is left on but not used for an extended period of time. Provisions have been made in order to disable the auto turn-off feature. Once the blowby/airflow indicator is disabled, the indicator will turn off only when the OFF button that is on the front panel is pressed. Use the following procedure to disable the auto turn-off feature.

  1. Remove the internal battery. Follow Step 1 and Step 2 in "Replacing the Internal Battery".



    Illustration 19g03033416

  1. Remove four screws (1) that are located on the corners of the small printed circuit board (2) .

    Note: Care must be taken when removing the small circuit board (2) in order to prevent damage to the conductors.

  1. Remove small circuit board (2) by using a small screwdriver to separate the connector from the circuit board. Remove the small circuit board (2) .



    Illustration 20g03033559

  1. Locate the connector for the auto turn-off feature on the large circuit board. The connector is located between the battery and the integrated circuit (40 pin).

  1. Lift the connector and move the connector to the next set of pins that are closest to the battery. This will disable the auto turn-off feature. Refer to the above illustration to show the proper location of the connector for each mode of operation.

  1. Carefully place the small circuit board (2) on top of the large printed circuit board. Ensure that the connector for the two circuit boards is properly aligned before you press the two circuit boards together.

  1. Install four screws (1) in the corners of small board (2). Replace the battery and install the rear cover.

Replacement of Serviced Parts for 8T-2701 Blowby Indicator Assembly

Removal Procedure for the 8T-0999 Membrane Switch

  1. Remove the rear cover and remove the internal battery. Follow Steps 1 and 2 in "Replacing the Internal Battery".

  1. Remove the small printed circuit board. Follow Step 3 and 4 in "Disabling the Auto Turn-off Feature (If Equipped)".



    Illustration 21g03033608

  1. Remove six screws (3). Lift up the printed circuit board (4) from the front cover. Be sure to lift the printed circuit board from the LCD end.



    Illustration 22g03033613

  1. Carefully remove the 8T-0999 Membrane Switch connector (5) from the connector pins (6) .

Replacement Procedure for the 8T-0844 Front Cover and the 8T-0999 Membrane Switch

Note: Always replace both the front cover and the membrane switch even if only one is damaged.

  1. Repeat steps 1 through 4 of "Removal Procedure for the 8T-0999 Membrane Switch"

  1. Start at the window end of the membrane switch. Carefully peel the backing from the 8T-0999 Membrane Switch while you align the membrane switch with the 8T-0844 Front Cover .

    Note: Before you glue the switch in place, make sure that the switch connector is properly installed through the slot in the front cover.

Replacing the 8T-0887 Connector Assembly or the 8T-1005 LCD Display




Illustration 23g03033777

  1. Repeat steps 1 through 4 of "Removal Procedure for the 8T-0999 Membrane Switch".

  1. Remove four screws (7) from circuit board (4) .



    Illustration 24g03033857



    Illustration 25g03035356

  1. Remove 8T-0887 Connector Assembly (8) and 8T-1005 LCD Display (12) from the circuit board.

    Note: The 8T-0887 Connector Assembly consists of the following items: Cover (10), Shield (11), LCD Display (12), Frame (13), and Strips (14) .

    Note: Do not touch strips (14) with bare hands. If the strips need to be placed into the slots in the frame (13), use tweezers.




    Illustration 26g03035436

  1. Discard damaged parts.

    Note: The pins on the bottom of the frame of the connector must fit into the holes (15) .




    Illustration 27g03035447

  1. Place the assembled frame (13) and strips (14) on the large circuit board.

  1. Hold the digital LCD display (12) in front of a light in order to determine which end the LO BAT display is on. Do not lose this orientation.

  1. Place the LCD display on top of the strips with the LO BAT on the left.

  1. Place shield (11) on top of the LCD display. Put cover (10) over the shield and install four screws (7) in the large circuit board.

  1. Make sure that the connector for the membrane switch (5) is properly aligned with the pins (6 on the large circuit board. Press the components together.)

  1. Install six screws (3). Carefully place the small circuit board on top of the large circuit board.

  1. Align the connector for the circuit boards before you press the two boards together.

  1. Install four screws (1) in the corners of the small circuit board (2). Replace the battery and the rear cover.

Repair Information

If the blowby/airflow indicator does not operate correctly, install a new internal battery. Recheck the operation. If the blowby/airflow indicator is faulty, contact Dealer Service Tools for repair locations.

Units that are less than one year old will be repaired under the warranty. The cost of repairs that are out of warranty will be charged to the owner.

Additional Contact Information

For additional product support questions concerning this tool, contact the Cat Dealer Service Tools Hotline at:

USA: 1-800-542-8665, Option 1

International: 1-309-578-7372

Email: dealerservicetool_hotline@cat.com

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