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Procedure For Installing Automatic Retarder Control (ARC) In 771D, 775D Quarry Trucks, 776D Tractors And 769D, 773D, 777D Off-Highway Trucks And Design Enhancements For Previously Equipped ARC Machines {3120, 3121, 3288, 4257, 4269, 4294, 4801} Caterpillar


Procedure For Installing Automatic Retarder Control (ARC) In 771D, 775D Quarry Trucks, 776D Tractors And 769D, 773D, 777D Off-Highway Trucks And Design Enhancements For Previously Equipped ARC Machines {3120, 3121, 3288, 4257, 4269, 4294, 4801}

Usage:

777D 3PR
Off-Highway Truck/Tractor
769D (S/N: 5TR1-UP)
773D (S/N: 7ER1-UP)
776D (S/N: 5ER1-UP)
777D (S/N: 3PR1-UP)
Quarry Truck
771D (S/N: 6JR1-UP)
775D (S/N: 6KR1-UP)

Introduction

Disregard Special Instruction, REHS0055, refer to this Special Instruction for the procedure.

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

This Special Instruction contains the necessary procedures and information needed to install Automatic Retarder Control (ARC) on 771D and 775D Quarry Trucks and 769D, 773D, and 777D Off-Highway Trucks. Also included are general instructions to update trucks already equipped with earlier ARC system designs to the latest design which includes a separate brake relay valve exclusively for automatic retarder control.

Components used for the complete ARC system retrofit are listed in the charts found at the beginning of each section in this special instruction. These components must be purchased individually from Morton Parts Distribution Center or the parts can be purchased as a complete retrofit kit through Decatur Custom Products using the following retrofit kit numbers.

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Table 1
Decatur Custom Products Retrofit Kits 
Kit Part number  Description 
3Z-6410  ARC Retrofit Kit for 769D Off-Highway Trucks and 771D Quarry Trucks 
3Z-6411  ARC Retrofit Kit for 773D Off-Highway Trucks and 775D Quarry Trucks 
3Z-6412  ARC Retrofit Kit for 777D Off-Highway Trucks equipped with dry front brakes and 776D Tractors 
3Z-6413  ARC Retrofit Kit for 777D Off-Highway Trucks equipped with wet front brakes 

The suggested tools and equipment should be readily available. If the tools are not available, assembly will be more difficult and more time will be necessary to complete the assembly

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NOTICE

Apply 5P-3413 Pipe Sealant to all fittings, connectors, and adapters with male tapered pipe threads which are used throughout this special instruction to prevent air leaks in the ARC brake lines. Air line leaks may prevent proper operation of truck brake controls.

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NOTICE

When installing fittings and connectors into threads of a non-ferrous material (non-steel), standard torques should be reduced by 50 percent. Overtightening to higher torques may damage mating threads causing air line leaks. Air line leaks may prevent proper operation of truck brake controls.

Some illustrations in this publication may be shown for illustrative purposes.

Reference: Parts Manual, SEBP2470, "796D Off-Highway Truck"

Reference: Parts Manual, SEBP2471, "771D Off-Highway Truck"

Reference: Parts Manual, SEBP2473, "773D Off-Highway Truck"

Reference: Parts Manual, SEBP2474, "775D Off-Highway Truck"

Reference: Parts Manual, SEBP2476, "777D Off-Highway Truck"

Reference: Special Instruction, SEHS9065, "Use of Ce/Ve Connector Tools"

Reference: Special Instruction, SEHS9615, "Servicing Deutsch HD and DT style connectors"

Reference: Service Manual, SENR5683, "Automatic Retarder Control Systems"

Each sections listed in the Contents below must be fully completed for installation of Automatic Retarder Control (ARC) System in all 771D, 775D Quarry Trucks, 776D Tractor, 769D, 773D, 777D Off-Highway Trucks with the following exceptions:

  • Install 146-1597 Retarder Control Group (not serviced) to 776D Tractors and 777D Off-Highway Trucks ONLY.

  • Install 146-1598 Retarder Control Group (not serviced) to 777D Off-Highway Trucks equipped with wet front brakes ONLY.

  • Install 146-1595 Retarder Control Group (not serviced) to 769D Off-Highway Trucks and 771D Quarry Trucks ONLY.

  • Install 146-1596 Retarder Control Group (not serviced) to 773D Off-Highway Trucks and 775D Quarry Trucks ONLY.

Complete one of the following two sections as follows:

  • For trucks presently equipped with former ARC system design, complete Section "Modify ARC Control Valve and Air Lines in ARC Equipped Trucks (127-4661)."

  • For non-ARC trucks, complete Section "Install ARC Control Valve in Non-ARC Trucks (127-4661)".

Install Retarder Control Group

Cab Preparation

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    Illustration 1g06107125
    View of front cab cover panel

  1. Remove 14 bolts, 14 washers, and the front cab cover.

  2. Raise the body and install the body retaining pins.
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    Illustration 2g06107135
    View of rear cab cover panel

  3. Remove four bolts, four washers, and the rear cab cover.
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    Illustration 3g06107144
    View of bottom cab cover panel

  4. Remove ten bolts, ten washers, and the bottom cab cover.

    Note: Remove the bottom cab cover panel to allow the routing of the front cab compartment air lines to the rear cab compartment.

Install 146-1597 Retarder Control Gp or 146-1598 Retarder Control Gp

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Table 2
146-1597 Retarder Control Gp(1) 
Item  Qty  Part Number  Description 
1  1  5T-7542  Plate 
2  2  002-6454  Pipe Nipple 
3  2  5M-3062  Bolt 3/8 - 16 
4  2  5P-1075  Hard Washer 
5  3  2H-3940  Elbow 
6  1  3J-5389  Plug 
7  1  2D-7325  Pipe Tee 
8  2  5H-4778  Elbow 
9  2  4H-6147  Connector 
10  1  147-6277  Check Valve Gp 
11  1  5P-8998  Fitting 
12  1  6D-3781  Check Valve Gp 
13  1  7D-4955  Hose As (Hose T) 
14  1  4S-6667  Hose As (Hose U) 
15  1  2G-1424  Hose As (Hose W) 
16  1  5D-7464  Hose As (Hose S) 
17  2  4J-6306  Identification Tag 
18  1  Fabricate  Block(2) 
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(1) Not Serviced
(2) Fabricate from Mild steel bar 13.5 mm (0.53 inch) MIN thick x 35 mm (1.38 inch) x 95 mm (3.7 inch). Drill and tap two 3/8–16 holes at a center distance of 52.3 mm (2.06 inch).
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Illustration 4g06107172
Air line schematic for former 777D trucks with dry front brakes and 776D Tractors.

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Table 3
146-1598 Retarder Control Gp(1) 
Item  Qty  Part Number  Description 
1  1  5T-7542  Plate 
2  2  002-6454  Pipe Nipple 
3  2  5M-3062  Bolt 3/8 - 16 
4  2  5P-1075  Hard Washer 
5  3  2H-3940  Elbow 
6  1  3J-5389  Plug 
7  1  2D-7325  Pipe Tee 
8  2  5H-4778  Elbow 
9  2  4H-6147  Connector 
10  1  147-6277  Check Valve Gp 
11  1  5P-8998  Fitting 
12  1  6D-3781  Check Valve Gp 
13  1  7D-4955  Hose As (Hose T) 
14  1  4S-6667  Hose As (Hose U) 
15  1  2G-1424  Hose As (Hose W) 
16  1  5D-7464  Hose As (Hose S) 
17  2  4J-6306  Identification Tag 
18  1  Fabricate  Block(2) 
19  1  4D-7645  Clip 
20  1  002-6454  Pipe Nipple(3) 
21  3  2H-3940  Elbow(3) 
22  1  147-6277  Check Valve Gp(3) 
23  1  3D-8928  Hose As 
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(1) Not Serviced
(2) Fabricate from Mild steel bar 13.5 mm (0.53 inch) MIN thick x 35 mm (1.38 inch) x 95 mm (3.7 inch). Drill and tap two 3/8–16 holes at a center distance of 52.3 mm (2.06 inch).
(3) This item for 777D Trucks equipped with WET front brakes only
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Illustration 5g06107213
Air line schematic for 777D equipped with WET front brakes

Note: It may be necessary to reposition existing brake relay valve(s) or fabricate and weld a suitable mounting plate rearward of existing brake relay valve(s) to allow adequate space for mounting the new ARC brake relay valve.

Note: Complete Steps 1 through 19 to install 146-1597 Retarder Control Group (not serviced) in 777D Off-Highway Trucks equipped with dry front brakes and in 776D Tractors. (See Table 2 for complete list of components).

Note: Steps 20 through 24 and Steps 1 through 19 should be used to install 146-1598 Retarder Control Group (not serviced) in 777D Off-Highway Trucks equipped with wet front brakes. Also, Steps 7 and 15 should be completed using the notes which follow each step. (See Table 3 for complete list of components).

  1. Disconnect existing connecting hardware and hoses (former Hose S and Hose Q) from existing rear brake relay valve side input port.

    Note: For locating mounting block (18), before welding block (18), position block (18) so relay valve mounting holes are aligned with the tapped holes in mounting block (18). Tack weld the mounting block (18) to the truck frame and disassemble the relay valve so welding can be completed.

  2. Weld Block (18) to frame rearward of existing relay valves for installation of new ARC relay valve.
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    Illustration 6g06107230
    Typical view of ARC relay valve installed

  3. Connect 5T-7242 Relay Valve Gp (1) to the existing rearward relay valve using one 002-6454 Pipe Nipple (2).

  4. Install 5T-7242 Relay Valve GP (1) to previously installed mounting block (18) using two 5M-3062 Bolts (3) and two 5P-1075 Washers (4).

  5. Remove former Hose S from connecting hardware that was previously disconnected from existing rear brake relay valve. Disconnect other end of former Hose S from the control valve mounted below the relay valves on the truck frame. Install 5D-7464 Hose Assembly (16) (new Hose S) in place of former Hose S.

  6. Install connecting hardware and hoses (new Hose S (16) and Hose Q) to the side input port of new ARC relay valve (1) installed in Step 3.

  7. Install 2H-3940 Elbow (5) and 2G-1424 Hose Assembly (15) (Hose W) to rear delivery port on front of the previously installed 5T-7242 Relay Valve Gp (1).

  8. Install 3J-5389 Plug (6) to the front delivery port (unused) on front of previously installed 5T-7242 Relay Valve GP (1).
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    Illustration 7g06107259
    Typical view of new hoses installed to ARC relay valve

  9. Install 2D-7325 Pipe Tee (7) to the top port of previously installed 5T-7242 Relay Valve GP (1).

  10. Install 5H-4778 Elbow (8) and 7D-4955 Hose Assembly (13) (Hose T) to vertical port of previously installed 2D-7325 Tee. Attach one 4J-6306 Identification Tag (17) to each end of new 7D-4955 Hose Assembly.

  11. Install 4H-6147 Connector (9) and 4S-6667 Hose Assembly (14) (Hose U) to the horizontal port of previously installed 5T-7242 Tee.
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    Illustration 8g06112279
    Typical view of double check valve installed to rear master cylinder

  12. Disconnect existing hose (Hose H) from 9D-3352 Elbow in rear master brake cylinder. Turn elbow 180 degrees into master cylinder. Install 002-6454 Nipple (2) to existing 9D-3352 Elbow.

  13. Install 135-9288 Double Check Valve (10) output port to previously installed 002-6454 Nipple.

  14. Install two 2H-3940 Elbows (5) and to previously installed 135-9288 Double Check Valve input ports.

  15. Connect previously installed 2G-1424 Hose Assembly (Hose W) and hose assembly previously disconnected from rear master brake cylinder (Hose H) to two elbows installed in the step above.
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    Illustration 9g06107296
    Typical view of new double check valve installed

  16. Disconnect existing hose from existing double check valve input port (between double check valve and rear relay valve) and install 5P-8998 Nipple (11).

  17. Install 6D-3781 Double Check Valve (12) output port to previously installed 5P-8998 Nipple.

  18. Install 5H-4778 Elbow (8) and hose assembly previously disconnected from double check valve input port (Hose K) to new 6D-3781 Double Check Valve front input port.

  19. Install 4H-6147 Connector (9) and previously installed 4S-6667 Hose Assembly (Hose U) to new 6D-3781 Double Check Valve front input port.

    Note: The following steps are only used when installing 146-1598 Retarder Control Group (not serviced) in 777D Off-Highway Trucks equipped with wet front brakes. (See Table 3 for complete list of components).

  20. Disconnect Hose (J) and existing connecting hardware from front master cylinder.

  21. Install 002-6454 Nipple (20) to front master cylinder. Install 147-6277 Double Check Valve (22) to the nipple. Install two 2H-3940 Elbows (21) to both ends of the double check valve.

  22. Remove existing 4D-6463 Clip from the rear left pedestal on truck frame. Install 4D-7645 Clip (19) in its place using existing fastening hardware.

  23. Install 3D-8928 Hose Assembly (23) (Hose X) to front delivery port on front of previously installed 5T-7242 Relay Valve using 2H-3940 Elbow (21).

  24. Route previously installed Hoses (X & W) through the clip to secure the hoses to the truck frame before installing to their respective double check valves. (See Steps 15 and 25).

  25. Connect previously installed 3D-8928 Hose Assembly (23) (Hose X) and existing Hose J to both elbows installed in Step 21.

Install 146-1595 Retarder Control Gp or 146-1596 Retarder Control Gp

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Table 4
146-1595 Retarder Control Gp(1) 
Item  Qty  Part Number  Description 
1  1  5T-7242  Relay Valve Gp 
2  1  002-6454  Pipe Nipple 
3  2  5M-3062  Bolt 3/8 - 16 
4  2  8T-4896  Hard Washer 
5  3  2H-3940  Elbow 
6  1  3J-53893J-5389  Plug 
7  1  3D-7325  Elbow 
8  2  147-6277  Check Valve Gp 
9  1  4D-7645  Clip 
10  1  8X-5982  Hose As (Hose S) 
11  1  8W-3150  Hose As (Hose T) 
12  1  8D-4973  Hose As (Hose U) 
13  2  Fabricate  Block(2) 
18  1  4J-6306  Identification Tag 
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(1) Not Serviced
(2) Fabricate from Mild steel bar 13.5 mm (0.53 inch) MIN thick x 35 mm (1.38 inch) x 95 mm (3.7 inch). Drill and tap two 3/8–16 holes at a center distance of 52.3 mm (2.06 inch).

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Table 5
146-1596 Retarder Control Gp(1) 
Item  Qty  Part Number  Description 
1  1  5T-7242  Relay Valve Gp 
2  1  002-6454  Pipe Nipple 
3  2  5M-3062  Bolt 3/8 - 16 
4  2  8T-4896  Hard Washer 
5  3  2H-3940  Elbow 
6  1  3J-5389  Plug 
7  1  3D-7325  Elbow 
8  2  147-6277  Check Valve Gp 
9  1  4D-7645  Clip 
10  1  7J-0703  Hose As (Hose S) 
11  1  3D-6872  Hose As (Hose T) 
12  1  8X-6262  Hose As (Hose U) 
13  2  Fabricate  Block(2) 
14  1  4D-3734  Elbow 
15  2  5H-7549  Clip 
16  1  6D-2834  Clip 
17  1  6D-4247  Clip 
18  1  4J-6306  Identification Tag 
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(1) Not Serviced
(2) Fabricate from Mild steel bar 13.5 mm (0.53 inch) MIN thick x 35 mm (1.38 inch) x 95 mm (3.7 inch). Drill and tap two 3/8–16 holes at a center distance of 52.3 mm (2.06 inch).

Note: Refer to 146-1597, 146-1598 Retarder Control Group Installation Procedure as typical examples for installing arc lines fittings. DO NOT route hoses as shown in these photos. Use Illustrations 4 for 777D machines with dry front brakes and 776D tractors. Use Illustration 5 for 776D machines with wet front brakes. Use the schematics for correct hose routings for this procedure.

Note: It may be necessary to reposition existing brake relay valve(s) or fabricate and weld a suitable mounting plate rearward of existing brake relay valve(s) to allow adequate space for mounting the new ARC brake relay valve.

Note: Complete Steps 1 through 12 ONLY to install 146-1595 Retarder Control Group (not serviced) in 769D Off-Highway Trucks and in 771D Quarry Trucks. (See Table 4 for complete list of components). Installation procedure for 146-1596 Retarder Control Group (not serviced) in 773D Off-Highway Trucks and in 775D Quarry Trucks is identical except for clips installed in Steps 13 through 16 and modifications to hose lengths and installation as noted after Steps 5, 7 and 8.

  1. Disconnect existing hardware and Hose M from existing rear brake relay valve side input port.

  2. Weld Block (13) to truck frame rearward of existing brake relay valve(s) for installation of new ARC brake relay valve.

    Note: For locating mounting block, complete Step 2 before welding block to position block so relay valve mounting holes are aligned with tapped holes in mounting block. Tack weld the mounting block to the truck frame and disassemble the relay valve so welding in Step 1 can be completed.

  3. Remove existing 3J-5389 Plug from rear supply port of brake relay valve. Install the plug to front supply port of 5T-7242 Relay Valve (1).

  4. Install 3J-5389 Plug (6) to unused delivery port of ARC relay valve.

  5. Install 2H-3940 Elbow (5) to rear supply port of 5T-7242 ARC Relay Valve. Install 5T-7242 ARC Relay Valve (1) to existing rearward brake relay valve by connecting 8D-4973 Hose Assembly (12) (Hose U) to the existing brake relay valve supply port and to the previously installed elbow.

    Note: When installing 146-1596 Retarder Control Group (not serviced) in 773D and 775D, substitute 8X-6262 Hose Assembly (12) for 8D-4973 (Hose U) in Step 5.

    Note: When installing 146-1596 Retarder Control Group (not serviced), the other end of the hose assembly (Hose U) must be connected to the supply port of existing middle brake relay valve using 4D-3734 Elbow (14). (See Table 5 for complete list of components).

  6. Install 5T-7242 Relay Valve to previously installed mounting block using two 5M-3062 Bolts (3) and two 8T-4896 Washers (4).

  7. Install 8W-3150 Hose Assembly (11) (Hose T) to delivery port of previously installed ARC relay valve using 2H-3940 Elbow (5).

    Note: When installing 146-1596 Retarder Control Group (not serviced) in 773D and 775D, substitute 3D-6872 Hose Assembly (11) for 8W-3150 (Hose T) in Step 7.

  8. Install 8X-5982 Hose Assembly (10) (Hose S) to top of previously installed ARC relay valve using 3D-7587 Elbow (7). Attach 4J-6306 Tag (18) to both ends of Hose S.

    Note: When installing 146-1596 Retarder Control Group (not serviced) in 773D and 775D, substitute 7J-0703 Hose Assembly (10) for 8X-5982 (Hose S) in Step 8.

  9. Route Hose S through existing clips on truck frame to (same clips as existing Hoses D and F) outside rear cab compartment interface panel and install to Port 6.

  10. Disconnect existing Hose M from rear master brake cylinder.

  11. Install 147-6277 Double Check Valve (8) to rear master brake cylinder using 002-6454 Nipple (2).

  12. Install two 2H-3940 Elbows (5) to both input ports on previously installed double check valve. Install existing Hose M and previously installed Hose T to the elbows.

    Note: The following steps are ONLY used to install 146-1596 Retarder Control Group (not serviced) in 773D Off-Highway Trucks and 775D Quarry Trucks. (See Table 5 for complete list of components).

  13. Remove two existing 4D-6463 Clips, one located directly below the inside left pedestal and one on front of the left pedestal. Replace the former clips with two 4D-7645 Clips (9) using the existing fastening hardware.

  14. Remove two existing 6D-1641 Clips from the top of center tube. Replace the former clips with two 5H-7549 Clips (15) using the existing fastening hardware. (Existing Hoses L, M, and Hose T).

  15. Remove existing 7J-8581 Clip from the rear center tube. Replace the former clip with 6D-2834 Clip (16) using the existing fastening hardware. (Existing Hoses D, E & Hose S).

  16. Remove existing 6D-4244 Clip from outside the left frame. Replace the former clip with 6D-4247 Clip (17) using the existing fastening hardware. (Existing Hose M & Hose T between brake master cylinders).

Install Read Cab Compartment Double Check Valve (6D-3781)

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Table 6
Parts Needed to Install new Rear Cab Compartment Double Check Valve 
Item  Qty  Part Number  Description 
1  1  6D-3781  Check Valve Gp 
2  1  6V-8801  Nut 
3  1  5S-7379  Bolt 
4  1  8T-4896  Hard Washer 
5  1  4H-6147  Connector 
6  1  4S-7562  Hose As (Hose Y) 
7  4  5H-4778  Elbow 
8  1  6D-9718  Hose As (Hose ZZ) 
9  1  9M-8662  Coupling 

Prepare Rear Cab Compartment for Double Check Valve Installation

Note: This procedure is necessary when retrofitting both non-ARC and ARC-equipped trucks.

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    Illustration 10g06107657
    Typical view of interface panel connections inside rear cab compartment.

  1. Remove three 4H-6147 Connectors from Ports 4, 7 & 8 on cab interface plate inside rear cab compartment. Replace with three 5H-4778 Elbows (7)

  2. Remove 5T-8285 Block, two 8T-4896 Washers and two 4L-6454 Bolts from Port 5 on cab interface plate inside rear cab compartment.

Install Double Check Valve

  1. Drill one 10.31 mm (0.406 in) hole in rear cab compartment floor.
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    Illustration 11g06107693
    View of double check valve installed inside rear cab compartment

  2. Install 6D-3781 Double Check Valve (1) to rear cab compartment floor using one 5S-7379 Bolt (3), one 6V-8801 Nut (2), and one 8T-4896 Washer (4).
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    Illustration 12g06107700
    View of Hose ZZ installed.

  3. Install 6D-9718 Hose Assembly (8) (Hose ZZ - from elbow on 5T-8285 Block) by connecting to output port of 6D-3781 Double Check Valve and to elbow on previously installed 5T-8285 Block.
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    Illustration 13g06107706
    View of Hoses Y and W installed.

  4. Install 4H-6147 Connector (5) to left input port of 6D-3781 Double Check Valve. Connect 4S-7562 Hose Assembly (6) (Hose Y - from front input port of front cab compartment double check valve) to the connector.

  5. Install 5H-4778 Elbow (7) to right input port of 6D-3781 Double Check Valve. Route previously installed 4S-7559 Hose Assembly (Hose W - from ARC double check valve output port) from front cab compartment to rear cab compartment and connect to the elbow.

    Note: For ease of assembly, attach the elbow and connector to fittings on 6D-3781 Double Check Valve before installing the double check valve to the rear cab compartment floor.

Modify ARC Control Valve And Air Lines In ARC Equipped Trucks (127-4661)

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Table 7
Parts needed to update Front Cab Arc Lines for Trucks Equipped with Former ARC System 
Item  Qty  Part Number  Description 
1  2  3J-1907  O-Ring Seal(1) 
2  3  2D-7325  Pipe Tee 
3  1  5H-4778  Elbow 
4  2  3D-7587  Elbow 
5  1  4M-5317  Reducer Bushing 
6  1  6D-9718  Hose As (Hose S) 
7  1  4S-7529  Hose As (Hose U) 
8  1  4S-7559  Hose As (Hose W) 
9  1  7D-3963  Hose As (Hose X) 
10  1  7D-2629  Hose As (Hose T) 
11  1  4D-6585  Pipe Elbow 
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(1) Optional Item - Required to replace worn O-rings if necessary

Note: Do not confuse Hoses (S,U,W,X,T) installed to ARC control valve with Hoses (S,U,W,X,T) previously installed to brake relay valve circuit in Section "Install Retarder Control Group".

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Illustration 14g06107763
View of former automatic retarder control valve connections.

  1. Remove existing 3D-6395 Hose Assembly (Hose C) (R1), 6J-1154 Hose Assembly (Hose B) (R2), two 4D-0582 Elbows (R3), 003-8470 Tee (R4), and 3B-7722 Bushing (R5) from 5P-4317 Connector (B) at rear supply port of 127-4661 Automatic Retarder Control Valve Group (A).

  2. Remove existing 3D-6395 Hose Assembly (Hose C) (R1) from port 3 on rear cab compartment side wall interface.

  3. Remove 6J-1154 Hose Assembly (Hose B) from service brake control valve (E) supply port.

  4. Disconnect existing 6D-3781 Double Check Valve (R6) from 5P-4317 Connector (B) at front delivery port of 127-4661 Automatic Retarder Control Valve Group (A).

    Note: Check 3J-1907 Seals (1) on existing 5P-4317 Connectors (B) for wear or damage. Replace with new seals if necessary.

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    Illustration 15g06112382
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    Illustration 16g06112389
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    Illustration 17g06112400
    View of existing automatic retarder control valve fastened to side wall of front cab compartment

  5. Disconnect existing sensor from wiring harness from existing ARC pressure switch and detach automatic retarder control valve from front cab compartment (C) side wall by removing two 8T-7008 Bolts (R7), four 8T-4896 Washers (R8), and two 9G-9150 Clips (R9).

    Note: Save all fastening hardware removed above for installation of newly configured automatic retarder control valve later in the special instruction.

  6. Remove existing 3D-8935 Hose Assembly (Hose D) (R10) and 4H-6147 Connector from bottom input port of 6D-3781 Double Check Valve (R12) and from the retarder brake control valve (D) delivery port.

  7. Remove existing 3D-8935 Hose Assembly (Hose A) (R11) and 4H-6147 Connector from side output port of 6D-3781 Double Check Valve (R12) and from right side input port of double check valve (F) on rear cab compartment floor.

  8. Install 2D-7325 Tee (2) to the bottom input port of double check valve previously removed from automatic retarder control valve.

  9. Install 5H-4778 Elbow (3) to horizontal port of 2D-7325 Tee installed above.

  10. Install 2D-7325 Tee (2) to the side output port of double check valve previously removed from automatic retarder control valve.

  11. Install 3D-7587 Elbow (4) to port on tee installed above which is perpendicular with direction of double check valve side output port.

  12. Install 4M-5317 Sensor Adapter (5) to port on tee installed above which is parallel with direction of double check valve side output port.

  13. Install 2D-7325 Tee (2) to the top input port of double check valve previously removed from automatic retarder control valve.

  14. Install 3D-7587 Elbow (4) to port on tee installed above which is parallel with direction of double check valve side output port.

    Note: To assure that all fittings are assembled tightly, hold ARC control valve with suitable vise and/or fixture while fastening fittings to the valve ports.

    Note: Take care not to over tighten fittings beyond 50 percent standard torque when fastening check valve and hose assemblies to automatic retarder control valve connectors. Over tightening may strip threads in the aluminum automatic retarder control valve block. (See NOTICE in the Introduction section at the beginning of the special instruction)

  15. Install newly fitted double check valve assembled above to the automatic retarder control valve front delivery port. Fasten vertical port of tee on previously disconnected double check valve top input port to existing fitting on automatic retarder control valve front delivery port.

  16. Install new automatic retarder control valve assembly to front cab compartment side wall using two 8T-7008 Bolts (R7), four 8T-4896 Washers (R8), and two 9G-9150 Clips (R9) previously removed in Step 5.

    Note: Use washers as stand offs between ARC control valve and cab side wall to prevent damage due to interference between non-flush surfaces.

  17. Install 6D-9718 Hose Assembly (6) (Hose S - from front cab compartment double check valve left side input port) to vertical port of tee on double check valve bottom input port. (Reference Step 8)

  18. Install 4S-7529 Hose Assembly (7) (Hose U - from manual retarder control valve delivery port) to the elbow on double check valve bottom input port. (Reference Steps 8 and 9)

  19. Install 4S-7559 Hose Assembly (8) (Hose W - from right side input port of double check valve on rear cab compartment floor) to vertical port of tee on double check valve side output port. (Reference Steps 10 and 11)

  20. Install existing retarder switch to horizontal port of tee on double check valve side output port. (Reference Steps 10 and 12)

  21. Install 7D-3963 Hose Assembly (9) (Hose X - from Port 6 inside front cab side panel) to the elbow on top input port of double check valve. (Reference Steps 13 and 14)

  22. Assemble 7D-2629 Hose Assembly (10) (Hose T - from tee on front left service brake control valve supply port) to 4D-6585 Elbow (11) and install the elbow to the existing connector on automatic retarder control valve rear supply port.

Install ARC Control Valve In Non-ARC Trucks (127-4661)

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Table 8
Parts Needed to Install Automatic Retarder Control Valve 
Item  Qty  Part Number  Description 
1  2  3J-1907  O-Ring Seal 
2  3  2D-7325  Pipe Tee 
3  1  5H-4778  Elbow 
4  2  3D-7587  Elbow 
5  1  4M-5317  Reducer Bushing 
6  1  6D-9718  Hose As 
7  1  4S-7529  Hose As 
8  1  4S-7559  Hose As 
9  1  7D-3963  Hose As 
10  1  7D-2629  Hose As 
11  1  6D-3781  Check Valve Gp 
12  2  5P-4317  Connector 
13  1  127-4661  Brake Valve and Mounting Gp 
14  2  8T-7008  Bolt 
15  4  8T-4896  Hard Washer 
16  2  9G-9150  Clip 
17  1  4D-6585  Pipe Elbow 
18  1  Not Used  Block 

Note: Do not confuse Hoses (S,U,W,X,T) installed to ARC control valve with Hoses (S,U,W,X,T) previously installed to brake relay valve circuit in Section "Install Retarder Control Group".

Note: Reference Illustrations 4 or 5 depending on host machine configuration for cab air lines schematic when completing the following procedure.

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Illustration 18g06108219
View of typical fixture used to hold double check valve while assembling fittings.
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Illustration 19g06108261
View of newly fitted double check valve for automatic retarder control valve front delivery port.

Note: To assure that all fittings are assembled tightly, hold double check valve with suitable vise and/or fixture while fastening fittings to the valve ports.

  1. Install 2D-7325 Tee (2) to the bottom input port of 6D-3781 Double Check Valve.

  2. Install 5H-4778 Elbow (3) to horizontal port of 2D-7325 Tee installed above.

  3. Install 2D-7325 Tee (2) to the side output port of 6D-3781 Double Check Valve.

  4. Install 3D-7587 Elbow (4) to port on tee installed above which is perpendicular with direction of double check valve side output port.

  5. Install 4M-5317 Sensor Adapter (5) to port on tee installed above which is parallel with direction of double check valve side output port.

  6. Install 2D-7325 Tee (2) to the top input port of 6D-3781 Double Check Valve.

  7. Install 2D-7325 Tee (2) to the top input port of 6D-3781 Double Check Valve.

    Note: To assure that all fittings are assembled tightly, hold automatic retarder control valve with suitable vise and/or fixture while fastening fittings to the valve ports.

    Note: Take care not to over tighten fittings beyond 50 percent standard torque when fastening fittings, check valve, and hose assemblies to automatic retarder control valve connectors. Over tightening may strip threads in the aluminum automatic retarder control valve block. (See NOTICE in Introduction section at the beginning of the special instruction)

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    Illustration 20g06108289
    View of newly assembled automatic retarder control valve.

  8. Install two 5P-4317 Connectors (12) to ARC control valve front delivery port and rear supply port.

  9. Install newly fitted 6D-3781 Double Check Valve (11) assembled above to the 127-4661 Automatic Retarder Control Valve (13) front delivery port. Fasten vertical port of tee on double check valve top input port to existing fitting on automatic retarder control valve front delivery port.
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    Illustration 21g06108351
    View of new automatic retarder control assembly installed to front cab compartment side wall.

  10. Weld Block (18) to side wall of front cab compartment.

    Note: The block installed in Step 10 is used as a stand off between the ARC control valve and the cab side wall to prevent valve damage due to interference of non-flush surfaces. If necessary, four 8T-4896 Washers installed in Step 11 may be substituted for Block (18) welded to front cab compartment side wall in Step 10.

  11. Install new automatic retarder control valve assembly to front cab compartment side wall using two 8T-7008 Bolts (14), four 8T-4896 Washers (15), and two 9G-9150 Clips (16).
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    Illustration 22g06108365
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    Illustration 23g06108383
    View of Arc control valve air lines installed.

  12. Connect 6D-9718 Hose Assembly (6) (Hose S - from left side of front compartment double check valve input port) to vertical port of tee on double check valve bottom input port. (Reference Step 1)

  13. Connect 4S-7529 Hose Assembly (7) (Hose U - from manual retarder control valve delivery port) to the elbow on double check valve bottom input port. (Reference Steps 1 and 2)

  14. Connect 4S-7559 Hose Assembly (8) (Hose W - from right side input port of double check valve on rear cab compartment floor) to vertical port of tee on double check valve side output port. (Reference Steps 3 and 4)

  15. Install existing retarder switch to horizontal port of tee on double check valve side output port. (Reference Steps 3 and 5)

  16. Connect 7D-3963 Hose Assembly (9) (Hose X - the Port 6 inside front cab side panel) to the elbow on top input port of double check valve. (Reference Steps 6 and 7)

  17. Assemble 7D-2629 Hose Assembly (10) (Hose T - from tee on front left service brake control valve supply port) to 4D-6585 Elbow (17) and install the elbow to the existing connector on automatic retarder control valve rear supply port.

Final ARC Air Line Connections In Cab

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Table 9
Miscellaneous Parts Needed to Finish ARC Cab Connections 
Item  Qty  Part Number  Description 
1  1  2D-7325  Pipe Tee 
1  1  5T-7242  Relay Valve Gp 
2  1  5D-9508  Hose As.(1) 
3  1  4J-8793  Hose As.(2) 
4  1  030-8327  Elbow 
5  1  9D-3551  Elbow 
6  1  003-6997  Extension Pipe Tee 
7  1  5H-4778  Elbow 
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(1) Used ONLY in 777D Trucks and 776D Tractors
(2) Used ONLY in 769D, 771D, 733D, and 775D Trucks

Note: This procedure includes cab connections which must be completed to finish ARC retrofits for both ARC-equipped and non-ARC trucks.

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    Illustration 24g06108883
    View of air lines installed to service brake control valve.

  1. Install 003-6997 Tee (6) to front supply port of service brake control valve. Connect previously installed Hose T and existing Hose J to each end of the tee.

  2. Install 5D-9508 Hose Assembly (2) (Hose M) to bottom right supply port of service brake control valve using 030-8324 Elbow (4). Also install Hose M to cab interface panel Port 3 inside rear cab compartment using existing 9D-3551 Elbow (5). (See Illustration 4 or 5 depending on host machine configuration)

    Note: When installing ARC to 769D, 771D, 773D, and 775D Trucks, replace 5D-9508 Hose Assembly with 4J-8793 Hose Assembly (3) as Hose M.

  3. Connect previously installed Hose U to existing connector on manual retarder control valve delivery port.
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    Illustration 25g06108971
    View of air lines installed to double check valve on front cab compartment floor.

  4. Connect previously installed Hose S to existing 5H-4778 Elbow (7) on left input port of double check valve on front cab compartment floor.

  5. Detach existing tee and existing Hoses C and K from right input port of double check valve on front cab compartment floor. (Refer to illustration 22)

  6. Connect previously installed Hose Y to double check valve input port using 2D-7325 Tee (1). Connect existing tee and Hoses C and K to the new tee.

  7. If necessary, remove existing hose, connector, and tee from between double check valve on front cab compartment floor and elbow attached to existing Hose R. Reconnect Hose R and elbow to the same double check valve output port.

  8. Connect previously installed Hose X to cab interface panel Port 6 inside rear cab compartment using existing hardware. (Refer to Illustrations 4 or 5 depending on host machine configuration)

Install ARC Electrical System

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Table 10
Parts Needed to Install ARC Electrical System 
Item  Qty  Part Number  Description 
1  2  9X-2044  Screw 
2  1  112-5572  Support 
3  5  5M-3062  Bolt 
4  1  112-6565  Support As 
5  1  3E-3663  Machine Electronic Control Module 
6  1  112-8242  Insulator 
7  1  117-2929  Engine Harness As 
8  1  3T-3046  Clip As 
9  1  9M-8406  Clip 
10  1  126-8862  Harness Assembly(1) 
11  1  126-8864  Harness Assembly(2) 
12  1  127-8867  Harness Assembly(3) 
13  1  127-8869  Harness Assembly(4) 
14  1  117-2933  Harness Assembly(5) 
15  1  4K-5122  Fuse Holder As 
16  1  3K-8782  Fuse 
17  1  125-2076  Rocker Switch 
18  7  3S-2093  Cable Strap 
19  4  8T-4896  Hard Washer 
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(1) For 769D Only
(2) For 771D Only
(3) For 773D Only
(4) For 775D Only
(5) For 776D & 777D Only

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Table 11
Tools Required 
Item  Qty  Part Number  Description 
1  1  1U-5804  Crimp Tool 
2  1  147-6456  Wedge Removal Tool 
3  1  6V-3001  Crimp Tool 
4  1  6V-3008  Contact Insertion Tool 
5  1  9S-9150  Terminal Crimp Tool As 

Note: This procedure is only necessary when installing an ARC system in non-ARC trucks. For retrofits in ARC-equipped trucks, complete Steps 12 through 14 and Step 16 ONLY.

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    Illustration 26g06108993
    View of partially installed ARC electronic control group (from left side of cab). (A) Rear of cab.
    Show/hide table
    Illustration 27g06108999
    View of partially installed ARC electronic control group (from rear of cab).

  1. Install 3E-3663 Control Group (5) using one 112-5572 Support (2), one 112-6565 Support (4), two 9X-2044 Screws (1), four 8T-4896 Washers (19), five 5M-3062 Bolts (3), and one 112-8242 Insulator (6).
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    Illustration 28g06109011
    View of partially installed ARC Harness. (A) ARC Control breakout. (B) Control breakout.

  2. Install 117-2929 Harness Assembly (7).

  3. Connect ARC Control breakout from 117-2929 Harness Assembly to 3E-3663 Control Group.

  4. Connect control breakout from 117-2929 Harness Assembly to pigtail from existing 3E-3663 Control Group. Secure the connection using one 3T-3046 Clip (8).
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    Illustration 29g06109035
    View of the partially installed ARC Harness. (A) Cab Harness breakout. (B) Code Harness breakout.

  5. Install one 9M-8406 Clip (9).

  6. Assemble cab harness breakout from 117-2929 Harness Assembly to the cab harness.

  7. Assemble code breakout from 117-2929 Harness Assembly to the appropriate code harness.

    Note: Depending on truck model, use the following Code Harness:

    For 769D, use 126-8862 Harness Assembly (10)

    For 771D, use 126-8864 Harness Assembly (11)

    For 773D, use 127-8867 Harness Assembly (12)

    For 775D, use 127-8869 Harness Assembly (13)

    For 777D, use 117-2933 Harness Assembly (14)

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    Illustration 30g06109045
    View of installed fuse from rear of cab.
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    Illustration 31g06110186
    View of installed fuse from inside cab.

  8. Install 3K-8782 Fuse (16) to 4K-5122 Holder Assembly (15). Assemble 4K-5122 Holder Assembly (15) to panel.

    Note: For holder installation, cut hole in film where auto retarder symbol is located using the panel as a guide.

  9. Remove tape from spare 112 PU wire in existing circuit breaker and assemble to 4K-5122 Holder Assembly.

  10. Remove tape from 176 OR wire in circuit breaker harness and assemble to the remaining terminal on the 4K-5122 Holder Assembly.
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    Illustration 32g06109464
    View of installed 117-2929 Harness Assembly from rear of cab.
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    Illustration 33g06109576
    View of 117-2929 Harness Assembly installed in the tunnel.

  11. Route remaining 117-2929 Harness Assembly through tunnel to front of cab.
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    Illustration 34g06109602
    View of pressure switches installed to ARC control valve. (A) ARC Pressure Switch. (B) Manual retarder pressure switch.

  12. Connect ARC Supply Valve breakout containing D989 BU and 202 BK wires from 117-2929 Harness Assembly to Arc Supply Valve. Secure the sure seal connection in the clip.

  13. Connect ARC Control Valve breakout from 117-2929 Harness Assembly to ARC Control Valve. Secure sure seal connector in the clip.

  14. Connect ARC Pressure Switch breakout containing D988 WH and 202 BK wires from 117-2929 Harness Assembly containing K991 OR and 202 BK wires to ARC Pressure Switch.

  15. Disconnect breakout in main cab harness from manual retarder pressure switch (B). Tie connector back to main cab harness.

  16. Connect retarder switch breakout from 117-2929 Harness Assembly containing K992 PU and 202 BK wires to manual retarder pressure switch.
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    Illustration 35g06109595
    View of installed switch assembly.

  17. Remove harness plug from dash harness at retarder lamp breakout.

  18. Remove plug from dash panel. Assemble 125-2076 (17) Switch Assembly to switch connector from existing dash harness. Install switch to dash panel.

  19. Connect Retarder Lamp breakout of 117-2929 Harness Assembly to dash harness.

  20. Secure harnesses as required using 3S-2093 Straps (18).
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    Illustration 36g06107125

  21. Replace fourteen bolts, fourteen washers, and cover on front of cab.
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    Illustration 37g06107135
    View of rear of cab.

  22. Replace four bolts, four washers, and cover on rear of cab.
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    Illustration 38g06107144
    View of bottom of cab.

  23. Replace ten bolts, ten washers, and cover below cab.

  24. Remove body retainer pins and lower truck body.

ARC Control Module Harness Assembly

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Illustration 39g06115054
ARC Control Module 117-2929 Harness Assembly
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Illustration 40g06109612
126-8862 Harness Assembly (769D)
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Illustration 41g06109898
126-8864 Harness Assembly (771D
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Illustration 42g06109933
127-8867 Harness Assembly (773D)
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Illustration 43g06110015
127-8869 Harness Assembly (775D)
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Illustration 44g06110036
117-2933 Harness Assembly (777D)

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