Procedure to Replace Brake Control Valve Components on Certain Large Off-Highway Trucks{4265, 4282} Caterpillar

Off-Highway Truck:

793F (S/N: SSP1-UP)

795F AC (S/N: ERM1-UP)

797 (S/N: 5YW1-UP)

797B (S/N: JSM1-UP)

797F (S/N: LAJ1-UP)

Introduction

ReferenceOperation and Maintenance Manual, "System Pressure Release"

ReferenceTesting and Adjusting, KENR8738, "Brake System Pressure - Test and Adjust"

ReferenceTesting and Adjusting, KENR8738, "Relief Valve (Main) - Test and Adjust"

ReferenceTesting and Adjusting, KENR8718, "Brake System Pressure - Test and Adjust"

ReferenceTesting and Adjusting, KENR8718, "Relief Valve (Main) - Test and Adjust"

ReferenceTesting and Adjusting, RENR2611, "Brake System Pressure - Test and Adjust"

ReferenceTesting and Adjusting, RENR2611, "Relief Valve (Brake Release Pump and Motor) - Test and Adjust"

ReferenceTesting and Adjusting, RENR2581, "Brake System Pressure - Test and Adjust"

ReferenceTesting and Adjusting, RENR2581, "Relief Valve (Brake Release Pump and Motor) - Test and Adjust"

ReferenceTesting and Adjusting, KENR8374, "Brake System Pressure - Test and Adjust"

ReferenceTesting and Adjusting, KENR8374, "Relief Valve (Main) - Test and Adjust"

New components are available for the brake control valve on certain Large Off-Highway Trucks. The new components on the brake control valve will help to prevent failures in the brake system. Refer to the following instructions for information on installing the new components on the brake control valve.

Required Parts

Safety

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine or release of air pressure or oil pressure can cause injury to persons on or near the machine. To help prevent possible injury before testing and adjusting any air system or hydraulic system, perform the procedure in the Testing and Adjusting, "General Information" section.

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Do not operate or work on this machine unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals. Failure to follow the instructions or heed the warnings could result in injury or death. Contact your Cat dealer for replacement manuals. Proper care is your responsibility.

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Accidental engine starting can cause injury or death to personnel working on the equipment. To avoid accidental engine starting, disconnect the battery cable from the negative (−) battery terminal. Completely tape all metal surfaces of the disconnected battery cable end in order to prevent contact with other metal surfaces which could activate the engine electrical system. Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

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Personal injury or death can result from improper lifting or blocking. When a hoist or jack is used to lift any part or component, stand clear of the area. Be sure the hoist or jack has the correct capacity to lift a component. Install blocks or stands before performance of any work under a heavy component. Approximate weights of the components are shown. Clean all surfaces where parts are to be installed.

Machine Preparation

1. Move the machine to a hard level surface.

2. Avoid sudden steering inputs when you are parking the machine.

3. Apply the service brakes in order to stop the machine.

4. Move the transmission control lever to the PARK position.

5. Raise the body.

6. Install the retaining cable. Refer to Operation and Maintenance Manual, "Cable (Truck Body Retaining) - Installation" for instructions on securing the truck body. Place the hoist control lever in the FLOAT position for at least 10 seconds.

7. Turn the engine start switch to the OFF position in order to stop the engine.

8. Ensure that the brake accumulators are fully discharged.

9. Turn the battery disconnect switch to the OFF position.

10. Disconnect the battery. Refer to Operation and Maintenance Manual, "Battery or Battery Cable - Inspect/Replace" for additional information disconnecting the battery.

11. Chock the front wheels and the rear wheels. Refer to Disassembly and Assembly, "Wheel Chock (Front and Rear) - Remove and Install".

Procedure for the 793F

1. Release the pressure from the system. Refer to Operation and Maintenance Manual, "System Pressure Release" for instructions on releasing the pressure.

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Illustration 1	g02424197
View of the top of the brake control valve (A) 301-7434 Tube As (1) 6V-9829 Cap As (2) 6V-9508 Plug (3) 221-3494 O-Ring Seal

2. Remove tube assembly (A). Retain tube assembly (A) .

3. Temporarily install two cap assemblies (1), two plugs (2), and two O-ring seals (3) to the tees.

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Illustration 2	g02424216
View of the rear of the brake control valve (B) 223-0016 Valve As (C) Plug (D) 262-1955 Solenoid Valve Gp (E) Orifice (F) Screen

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Illustration 3	g02417396
(B) 223-0016 Valve As (C) Plug (D) 262-1955 Solenoid Valve Gp (E) Orifice (F) Screen

4. Remove valve assembly (B) from the rear of the control valve. Discard valve assembly (B) .

5. Remove plug (C), orifice (E), and screen (F) from the "OR1" port on the control valve. Discard orifice (E) and screen (F). Retain plug (C) .

   Note: Screen (F) can be removed with an O-ring pick or a magnet.

   Note: Screen (F) must be removed. Failure to remove screen (F) will stop the brake system from charging the brake accumulators.

6. Remove solenoid valve group (D) from the control valve.
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   Illustration 4	g02640696
   View of 262-1955 Solenoid Valve Gp (D) (G) O-ring seal (H) Screen (4) 033-6028 O-Ring Seal (5) 033-5853 O-Ring Seal (6) 030-0167 Backup Ring

   1. Using an O-ring pick, remove O-ring (G) and screen (H) from solenoid valve group (D). Discard O-ring (G) and screen (H) .

      Note: If screen (H) is NOT damaged, and solenoid valve group (D) is NOT contaminated, reinstall solenoid valve group (D) with one O-ring seal (4), one O-ring seal (5), and one backup ring (6) .

      Note: If screen (H) IS damaged, and solenoid valve group (D) IS contaminated, discard the parts and refer to Step 9.

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Illustration 5	g02640818
(C) Plug (7) 371-4188 Control Valve Gp (8) 370-8748 Orifice Assembly (9) 262-1956 Solenoid Valve Gp

7. Install one valve assembly (7) into the control valve. Tighten valve assembly (7) to a torque of 107 ± 7 N·m (79 ± 5 lb ft).

   Note: Valve assembly (7) is a replacement for valve assembly (B) that was removed in Step 4.

8. Install one orifice assembly (8) and plug (C) into the "OR1" port. Tighten orifice assembly (8) to a torque of 5 ± 1 N·m (44 ± 9 lb in). Tighten plug (C) to a torque of 35 + 4 - 0 N·m (26 ± 2.9 lb ft).

   Note: Orifice assembly (8) is a replacement for orifice (E) and screen (F) that were removed in Step 5.

   Note: Plug (C) was removed in Step 5.

9. If needed, install one solenoid valve group (9) into the control valve. Tighten solenoid valve group (9) to a torque of 46 ± 1.6 N·m (34 ± 1.1 lb ft). Tighten the top nut on solenoid valve group (9) to a torque of 9.1 ± 1.5 N·m (6.7 ± 1.1 lb ft).

   Note: Solenoid valve group (9) is a replacement for solenoid valve group (D) that was removed in Step 6.

   Note: A new solenoid valve group (9) is only required if solenoid valve group (D) has been damaged. Refer to Step 6.a.

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Illustration 6	g02424236
View of the front of the brake control valve (J) 277-1873 Clip (K) 8T-4137 Bolt (L) 8T-4121 Hard Washer (M) 340-1890 Chassis Harness-As (N) 8T-4956 Bolt (P) 237-1957 Hose As

10. Remove one clip (J), one bolt (K), one washer (L), and two cable straps that secure harness assembly (M). Move harness assembly (M) enough to work next to the brake control valve. Retain the hardware.

11. Remove bolt (N). Retain the bolt. Move "TSB" hose assembly (P) enough to work next to the brake control valve.

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Illustration 7	g02640836
View of the front of the brake control valve (R) Tube assembly (10) 235-2476 Rectangular Seal

12. Remove the four bolts that secure tube assembly (R) to the "TANK" port on the brake control valve. Move tube assembly (R) enough to work next to the brake control valve. Retain the hardware.

    Note: The existing 235-2476 Rectangular Seal (10) must be replaced before reattaching tube assembly (R) .

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Illustration 8	g02423756
View of the front of the brake control valve (S) 320-8118 Relief Valve Gp

13. Remove relief valve group (S) from the "RV1" port on the brake control valve.

14. Install one relief valve group (11) into the "RV1" port on the brake control valve. Tighten relief valve group (11) to a torque of 101 ± 6.8 N·m (74 ± 5 lb ft).

    Note: Relief valve group (11) is a replacement for relief valve group (S) that was removed in Step 13.

15. After all the new components are installed, reconnect all the hoses and tubes that were disconnected in the previous steps.

    Note: A new 235-2476 Rectangular Seal (10) will need to be used when connecting tube assembly (R) to the brake control valve. Tube assembly (R) was removed in Step 12.

16. Purge the air from the brake system. Refer to the Testing and Adjusting, KENR8738, "Brake System Air - Purge"

17. Perform a brake system pressure test. Refer to Testing and Adjusting, KENR8738, "Brake System Pressure - Test and Adjust".

18. Test the main relief valve. Refer to Testing and Adjusting, KENR8738, "Relief Valve (Main) - Test and Adjust".

Procedure for the 795F AC

1. Release the pressure from the system. Refer to Operation and Maintenance Manual, "System Pressure Release" for instructions on releasing the pressure.

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Illustration 9	g02424316
View of the right side of the brake control valve (A) Bolt (B) Harness assembly (C) 320-8118 Relief Valve Gp

2. Remove one bolt (A) that secures the clip for harness assembly (B). Retain bolt (A) .

3. Loosen harness assembly (B) enough so that relief valve group (C) can be removed. Remove relief valve group (C) from the "RV1" port. Discard relief valve group (C) .

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Illustration 10	g02426579
View of the right side of the brake control valve (1) 371-5992 Relief Valve Gp

4. Install one relief valve group (1) into the "RV1" port on the brake control valve. Tighten relief valve group (1) to a torque of 101 ± 6.8 N·m (74 ± 5 lb ft).

   Note: Relief valve group (1) is a replacement for relief valve group (C) that was removed in Step 3.

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Illustration 11	g02424317
View of the left side of the brake control valve (D) Hose assembly to the "TSB" port (E) Hose assembly to the "ACC2" port (2) 6V-9833 Cap As (3) 6V-9512 Plug (4) 6V-9830 Cap As (5) 6V-9509 Plug (6) 228-7093 O-Ring Seal

5. Disconnect hose assembly (D) and hose assembly (E) from the left side of the brake control valve.

6. Temporarily install one cap assembly (2) on the end of hose assembly (E). Temporarily install one plug (3) into the "ACC2" port on the brake control valve.

7. Temporarily install one cap assembly (4) on the end of hose assembly (E). Temporarily install one plug (5) and one O-ring seal (6) into the "TSB" port on the brake control valve.

8. Move hose assembly (D) and hose assembly (E) away from the brake control valve. Ensure that there is enough room to remove the components in the steps below.

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Illustration 12	g02424336
View of the left side of the brake control valve

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Illustration 13	g02426518
(F) 223-0016 Valve As (G) Plug (H) 262-1955 Solenoid Valve Gp (J) Orifice (K) Screen

9. Remove valve assembly (F) from the rear of the control valve. Discard valve assembly (F) .

10. Remove plug (G), orifice (J), and screen (K) from the "OR1" port on the control valve. Discard orifice (J) and screen (K). Retain plug (G) .

    Note: Screen (K) can be removed with an O-ring pick or a magnet.

    Note: Screen (K) must be removed. Failure to remove screen (K) will stop the brake system from charging the brake accumulators.

11. Remove solenoid valve group (H) from the control valve.
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    Illustration 14	g02640859
    View of 262-1955 Solenoid Valve Gp (H) (J) O-ring (K) Screen (7) 033-6028 O-Ring Seal (8) 033-5853 O-Ring Seal (9) 030-0167 Backup Ring

    1. Using an O-ring pick, remove O-ring (J) and screen (K) from solenoid valve group (H). Discard O-ring (J) and screen (K) .

       Note: If screen (K) is NOT damaged, and solenoid valve group (H) is NOT contaminated, reinstall solenoid valve group (H) with one O-ring seal (7), one O-ring seal (8), and one backup ring (9) .

       Note: If screen (K) IS damaged, and solenoid valve group (H) IS contaminated, discard the parts and refer to Step 14.

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Illustration 15	g02641496
(G) Plug (10) 371-4188 Control Valve Gp (11) 370-8748 Orifice Assembly (12) 262-1956 Solenoid Valve Gp

12. Install one valve assembly (10) into the control valve. Tighten valve assembly (10) to a torque of 107 ± 7 N·m (79 ± 5 lb ft).

    Note: Valve assembly (10) is a replacement for valve assembly (F) that was removed in Step 9.

13. Install one orifice assembly (11) and plug (G) into the "OR1" port. Tighten orifice assembly (11) to a torque of 5 ± 1 N·m (44 ± 9 lb in). Tighten plug (G) to a torque of 35 + 4 - 0 N·m (26 ± 2.9 lb ft).

    Note: Orifice assembly (11) is a replacement for orifice (J) and screen (K) that were removed in Step 10.

    Note: Plug (G) was removed in Step 10.

14. If needed, install one solenoid valve group (12) into the control valve. Tighten solenoid valve group (12) to a torque of 46 ± 1.6 N·m (34 ± 1.1 lb ft). Tighten the top nut on solenoid valve group (12) to a torque of 9.1 ± 1.5 N·m (6.7 ± 1.1 lb ft).

    Note: Solenoid valve group (12) is a replacement for solenoid valve group (H) that was removed in Step 11.

    Note: A new solenoid valve group (12) is only required if solenoid valve group (H) has been damaged. Refer to Step 11.a.

15. After all the new components are installed, reconnect all the hoses and tubes that were disconnected in the previous steps.

16. Purge the air from the brake system. Refer to the Testing and Adjusting manual for information on purging the air from the brake system.

17. Purge the air from the brake system. Refer to the Testing and Adjusting, KENR8718, "Brake System Air - Purge"

18. Perform a brake system pressure test. Refer to Testing and Adjusting, KENR8718, "Brake System Pressure - Test and Adjust".

19. Test the main relief valve. Refer to Testing and Adjusting, KENR8718, "Relief Valve (Main) - Test and Adjust".

Procedure for the 797

1. Release the pressure from the system. Refer to Operation and Maintenance Manual, "System Pressure Release" for instructions on releasing the pressure.

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Illustration 16	g02435036
(A) Hose assembly (B) Hose assembly (C) Hose assembly (1) 6V-9512 Plug (2) 6V-9833 Cap As (3) 228-7093 O-Ring Seal (4) 6V-9511 Plug (5) 6V-9832 Cap As (6) 228-7092 O-Ring Seal (7) 6V-9508 Plug (8) 6V-9829 Cap As (9) 228-7089 O-Ring Seal

2. Disconnect hose assembly (A) from the brake control valve.

3. Temporarily install one plug (1) into hose assembly (A). Temporarily install one cap assembly (2) and one O-ring seal (3) to the elbow for hose assembly (A) .

4. Disconnect hose assembly (B) and the O-ring seal from the tee fitting below the brake accumulator. Discard the O-ring seal.

5. Temporarily install one plug (4) into hose assembly (B). Temporarily install one cap assembly (5) and one O-ring seal (6) to the tee fitting for hose assembly (B) .

6. Disconnect hose assembly (C) from the brake control valve.

7. Temporarily install one plug (7) into hose assembly (C). Temporarily install one cap assembly (8) and one O-ring seal (9) to the elbow for hose assembly (C) .

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Illustration 17	g02435817
Typical view of the rear of the brake control valve (D) 320-8118 Relief Valve Gp (E) 223-0016 Valve As (F) 262-1955 Solenoid Valve Gp (G) 262-1955 Solenoid Valve Gp

8. Remove relief valve group (D), valve assembly (E), solenoid valve group (F), and solenoid valve group (G) from the brake control valve. Discard relief valve group (D), valve assembly (E), and solenoid valve group (G). Proceed to Step 8.a for solenoid valve group (F) .
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   Illustration 18	g02641497
   View of 262-1955 Solenoid Valve Gp (F) (H) O-ring (J) Screen (10) 033-6028 O-Ring Seal (11) 033-5853 O-Ring Seal (12) 030-0167 Backup Ring

   1. Using an O-ring pick, remove O-ring (H) and screen (J) from solenoid valve group (F). Discard O-ring (H) and screen (J) .

      Note: If screen (J) is NOT damaged, and solenoid valve group (F) is NOT contaminated, reinstall solenoid valve group (F) with one O-ring seal (10), one O-ring seal (11), and one backup ring (12) .

      Note: If screen (J) IS damaged, and solenoid valve group (F) IS contaminated, discard the parts and refer to Step 12.

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Illustration 19	g02641516
Typical view of the rear of the brake control valve (13) 371-5992 Relief Valve Gp (14) 371-4188 Control Valve Gp (15) 262-1956 Solenoid Valve Gp (16) 371-4187 Solenoid Valve Gp

9. Install one relief valve group (13) to the rear of the brake control valve. Tighten relief valve group (13) to a torque of 101 ± 6.8 N·m (74 ± 5 lb ft).

10. Install one valve assembly (14) to the rear of the brake control valve. Tighten valve assembly (14) to a torque of 107 ± 7 N·m (79 ± 5 lb ft).

11. Install one solenoid valve group (16) to the right side of the brake control valve. Tighten solenoid valve group (16) to a torque of 46 ± 1.6 N·m (34 ± 1.1 lb ft). Tighten the top nut on solenoid valve group (16) to a torque of 9.1 ± 1.5 N·m (80 ± 13 lb in).

12. If needed, install one solenoid valve group (15) to the rear of the brake control valve. Tighten solenoid valve group (15) to a torque of 46 ± 1.6 N·m (34 ± 1.1 lb ft). Tighten the top nut on solenoid valve group (15) to a torque of 9.1 ± 1.5 N·m (80 ± 13 lb in).

    Note: Solenoid valve group (15) is a replacement for solenoid valve group (F) that was removed in Step 8.

    Note: Solenoid valve group (15) is only required if solenoid valve group (F) has been damaged. Refer to Step 8.a.

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Illustration 20	g02435837
Typical view of the bottom of the brake control valve (K) Plug (L) Orifice (M) Screen

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Illustration 21	g02435839
Typical sectional view of the bottom of the brake control valve (K) Plug (L) Orifice (M) Screen

13. Remove plug (K), orifice (L), and screen (M) from the bottom of the brake control valve. Discard orifice (L) and screen (M). Retain plug (K) .

    Note: Screen (M) can be removed with an O-ring pick or a magnet.

    Note: Screen (M) must be removed. Failure to remove screen (M) will stop the brake system from charging the brake accumulators.

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Illustration 22	g02641517
Typical view of the bottom of the brake control valve (K) Plug (17) 370-8748 Orifice Assembly

14. Install one orifice assembly (17) and plug (K) to the bottom of the brake control valve. Tighten orifice assembly (17) to a torque of 5 ± 1 N·m (44 ± 9 lb in). Tighten plug (K) to a torque of 35 + 4 - 0 N·m (26 + 2.9 - 0 lb ft).

15. After all the new components are installed, reconnect all the hoses that were disconnected in the previous steps.

    Note: The O-ring seal that was removed in Step 4 must be replaced with a new 6V-9746 O-Ring Seal .

16. Purge the air from the brake system. Refer to the Testing and Adjusting manual for information on purging the air from the brake system.

17. Purge the air from the brake system. Refer to the Testing and Adjusting, RENR2611, "Brake System Air - Purge"

18. Perform a brake system pressure test. Refer to Testing and Adjusting, RENR2611, "Brake System Pressure - Test and Adjust".

19. Test the main relief valve. Refer to Testing and Adjusting, RENR2611, "Relief Valve (Brake Release Pump and Motor) - Test and Adjust".

Procedure for the 797B

1. Release the pressure from the system. Refer to Operation and Maintenance Manual, "System Pressure Release" for instructions on releasing the pressure.

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Illustration 23	g02424338
View of the right side of the brake control valve (A) 254-1159 Tube As

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Illustration 24	g02424339
View of the right side of the brake control valve (A) 254-1159 Tube As (1) 6V-9512 Plug (2) 6V-9833 Cap As (3) 228-7093 O-Ring Seal

2. Slightly loosen the front connection of tube assembly (A). Completely disconnect tube assembly (A) from the rear connection.

3. Temporarily install one plug (1) into the end of tube assembly (A).

4. Temporarily install one cap assembly (2) and one O-ring seal (3) to the tee.

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Illustration 25	g02423977
Typical view of the rear of the brake control valve (B) 320-8118 Relief Valve Gp (C) 223-0016 Valve As (D) 262-1955 Solenoid Valve Gp (E) 262-1955 Solenoid Valve Gp

5. Remove relief valve group (B), valve assembly (C), and solenoid valve groups (D), and solenoid valve group (E) from the brake control valve. Discard relief valve group (B), valve assembly (C), and solenoid valve group (E). Proceed to Step 5.a for solenoid valve group (D) .
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   Illustration 26	g02641536
   View of 262-1955 Solenoid Valve Gp (D) (F) O-ring (G) Screen (4) 033-6028 O-Ring Seal (5) 033-5853 O-Ring Seal (6) 030-0167 Backup Ring

   1. Using an O-ring pick, remove O-ring (F) and screen (G) from solenoid valve group (D). Discard O-ring (F) and screen (G) .

      Note: If screen (G) is NOT damaged, and solenoid valve group (D) is NOT contaminated, reinstall solenoid valve group (D) with one O-ring seal (4), one O-ring seal (5), and one backup ring (6) .

      Note: If screen (G) IS damaged, and solenoid valve group (D) IS contaminated, discard the parts and refer to Step 9.

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Illustration 27	g02641537
View of the rear of the brake control valve (7) 371-5992 Relief Valve Gp (8) 371-4188 Control Valve Gp (9) 262-1956 Solenoid Valve Gp (10) 371-4187 Solenoid Valve Gp

6. Install one relief valve group (7) to the rear of the brake control valve. Tighten relief valve group (7) to a torque of 101 ± 6.8 N·m (74 ± 5 lb ft).

7. Install one valve assembly (8) to the rear of the brake control valve. Tighten valve assembly (8) to a torque of 107 ± 7 N·m (79 ± 5 lb ft).

8. Install one solenoid valve group (10) to the right side of the brake control valve. Tighten solenoid valve group (10) to a torque of 46 ± 1.6 N·m (34 ± 1.1 lb ft). Tighten the top nut on solenoid valve group (10) to a torque of 9.1 ± 1.5 N·m (80 ± 13 lb in).

9. If needed, install one solenoid valve group (9) to the rear of the brake control valve. Tighten solenoid valve group (9) to a torque of 46 ± 1.6 N·m (34 ± 1.1 lb ft). Tighten the top nut on solenoid valve group (9) to a torque of 9.1 ± 1.5 N·m (80 ± 13 lb in).

   Note: Solenoid valve group (9) is a replacement for solenoid valve group (D) that was removed in Step 5.

   Note: Solenoid valve group (9) is only required if solenoid valve group (D) has been damaged. Refer to Step 5.a.

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Illustration 28	g02424341
View of the bottom of the brake control valve (H) Plug (J) Orifice (K) Screen

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Illustration 29	g02446839
Sectional view of the bottom of the brake control valve (H) Plug (J) Orifice (K) Screen

10. Remove plug (H), orifice (J), and screen (K) from the bottom of the brake control valve. Discard orifice (J) and screen (K). Retain plug (H) .

    Note: Screen (K) can be removed with an O-ring pick or a magnet.

    Note: Screen (K) must be removed. Failure to remove screen (K) will stop the brake system from charging the brake accumulators.

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Illustration 30	g02641556
(H) Plug (11) Orifice As

11. Install one orifice assembly (11) and plug (H) to the bottom of the brake control valve. Tighten orifice assembly (11) to a torque of 5 ± 1 N·m (44 ± 9 lb in). Tighten plug (H) to a torque of 35 + 4 - 0 N·m (26 + 2.9 - 0 lb ft).

12. After all the new components are installed, reconnect all the hoses and tubes that were disconnected in the previous steps.

13. Purge the air from the brake system. Refer to the Testing and Adjusting manual for information on purging the air from the brake system.

14. Purge the air from the brake system. Refer to the Testing and Adjusting, RENR2581, "Brake System Air - Purge"

15. Perform a brake system pressure test. Refer to Testing and Adjusting, RENR2581, "Brake System Pressure - Test and Adjust".

16. Test the main relief valve. Refer to Testing and Adjusting, RENR2581, "Relief Valve (Brake Release Pump and Motor) - Test and Adjust".

Procedure for the 797F

1. Release the pressure from the system. Refer to Operation and Maintenance Manual, "System Pressure Release" for instructions on releasing the pressure.

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Illustration 31	g02432456
View of the right side of the brake control valve (A) Bolt (B) Hose assembly (C) Hose assembly (D) Elbow (1) 6V-9833 Cap As (2) 228-7093 O-Ring Seal (3) 6V-9512 Plug

2. Remove one bolt (A) that secures hose assembly (B) to hose assembly (C). Retain bolt (A). Move hose assembly (B) enough to work on the rear of the brake control valve.

3. Disconnect hose assembly (C) from elbow (D) on the "T2" port.

4. Temporarily install one cap assembly (1) and one O-ring seal (2) on elbow (D) .

5. Temporarily install one plug (3) onto hose assembly (C) .

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Illustration 32	g02432577
Typical view of the rear of the brake control valve (E) 223-0016 Valve As (F) Plug (G) 262-1955 Solenoid Valve Gp (H) Orifice (J) Screen

6. Remove valve assembly (E) from the rear of the control valve. Discard valve assembly (E) .

7. Remove plug (F), orifice (H), and screen (J) from the "OR1" port on the control valve. Discard orifice (H) and screen (J). Retain plug (F) .

   Note: Screen (J) can be removed with an O-ring pick or a magnet.

   Note: Screen (J) must be removed. Failure to remove screen (J) will stop the brake system from charging the brake accumulators.

8. Remove solenoid valve group (G) from the control valve.
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   Illustration 33	g02641559
   View of 262-1955 Solenoid Valve Gp (G) (K) O-ring (L) Screen (4) 033-6028 O-Ring Seal (5) 033-5853 O-Ring Seal (6) 030-0167 Backup Ring

   1. Using an O-ring pick, remove O-ring (K) and screen (L) from solenoid valve group (G). Discard O-ring (K) and screen (L) .

      Note: If screen (L) is NOT damaged, and solenoid valve group (G) is NOT contaminated, reinstall solenoid valve group (G) with one O-ring seal (4), one O-ring seal (5), and one backup ring (6) .

      Note: If screen (L) IS damaged, and solenoid valve group (G) IS contaminated, discard the parts and refer to Step 11.

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Illustration 34	g02641560
(F) Plug (7) 371-4188 Control Valve Gp (8) 370-8748 Orifice Assembly (9) 262-1956 Solenoid Valve Gp

9. Install one valve assembly (7) into the control valve. Tighten valve assembly (7) to a torque of 107 ± 7 N·m (79 ± 5 lb ft).

   Note: Valve assembly (7) is a replacement for valve assembly (E) that was removed in Step 6.

10. Install one orifice assembly (8) and plug (F) into the "OR1" port. Tighten orifice assembly (8) to a torque of 5 ± 1 N·m (44 ± 9 lb in). Tighten plug (F) to a torque of 35 + 4 - 0 N·m (26 + 2.9 - 0 lb ft).

    Note: Orifice assembly (8) is a replacement for orifice (H) and screen (J) that were removed in Step 7.

    Note: Plug (F) was removed in Step 7.

11. If needed, install one solenoid valve group (9) into the control valve. Tighten solenoid valve group (9) to a torque of 46 ± 1.6 N·m (34 ± 1.1 lb ft). Tighten the top nut on solenoid valve group (9) to a torque of 9.1 ± 1.5 N·m (6.7 ± 1.1 lb ft).

    Note: Solenoid valve group (9) is a replacement for solenoid valve group (G) that was removed in Step 8.

    Note: A new solenoid valve group (9) is only required if solenoid valve group (G) has been damaged. Refer to Step 8.a.

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Illustration 35	g02432762
View of the front of the brake control valve (M) Hose assembly (N) Bolt (P) Half flange (R) Solenoid valve group

12. Remove two bolts (N) that secures half flange (P). Remove half flange (P) that secures hose assembly (M) to the "TANK" port on the brake control valve. Retain the hardware.

13. Remove solenoid valve group (R) from the "SV1" port on the brake control valve. Retain solenoid valve group (R) .

    Note: For retention, solenoid valve group (R) should be placed in a clean plastic bag.

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Illustration 36	g02641561
View of the front of the brake control valve (S) 320-8118 Relief Valve Gp (10) 9S-4190 O-Ring Plug

14. Temporarily install one O-ring plug (10) into the "SV1" port.

    Note: Solenoid valve group (R) was removed from the "SV1" port in Step 13.

15. Remove relief valve group (S) from the "RV1" port on the brake control valve. Discard relief valve group (S) .

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Illustration 37	g02641562
View of the front of the brake control valve (11) 371-5992 Relief Valve Gp

16. Install one relief valve group (11) into the "RV1" port on the brake control valve. Tighten relief valve group (11) to a torque of 101 ± 6.8 N·m (74 ± 5 lb ft).

17. After the new components are installed, reconnect the hose assemblies that were disconnected, and reinstall the components that were not discarded in the previous steps.

18. Purge the air from the brake system. Refer to the Testing and Adjusting manual for information on purging the air from the brake system.

19. Purge the air from the brake system. Refer to the Testing and Adjusting, KENR8374, "Brake System Air - Purge"

20. Perform a brake system pressure test. Refer to Testing and Adjusting, KENR8374, "Brake System Pressure - Test and Adjust".

21. Test the main relief valve. Refer to Testing and Adjusting, KENR8374, "Relief Valve (Main) - Test and Adjust".