Usage:
NOTE: See the Systems Operation/Testing & Adjusting and the Specifications Manuals and the topic "Suspension Cylinders" for additional information. The procedure is the same to remove and install either the right or left suspension cylinder.
1. Make sure the vehicle is on level ground.
Typical Example
2. Disconnect lubrication lines (1) and (3) from the rear suspension cylinder.
3. Disconnect payload monitoring lines (2) from the suspension cylinder.
Typical Example
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Do not, under any condition, remove valves or plugs from the cylinder unless the rod is fully retracted and all nitrogen pressure is released. Do not stand under the vehicle when it is lifted or lowered. The machine can drop quickly. The vehicle must be empty and on level group to release the nitrogen pressure. |
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4. Put two 50 ton screw jacks (4) in position under the machine as shown. Raise the jacks until they support the weight of the machine.
Typical Example
5. Install tooling (A) on the nitrogen valve on both cylinders.
6. Turn the valve on the chucks clockwise to release the nitrogen from the rear suspension cylinders.
7. Use the two 50 ton screw jacks to lower the machine until the rear suspension cylinders are completely retracted.
Typical Example
8. Remove the nut, bolt (5) and two washers (6) from the pin that holds to top of the rear suspension cylinders to the frame.
Typical Example
9. Fasten a hoist to rear suspension cylinder (8). Remove pin (7).
10. Use the hoist to lower the top of the rear suspension cylinder. Lower the top of the cylinder until it is even with the bottom on the differential housing.
Typical Example
11. Fasten a nylon strap and tooling (B) to the hoist and rear suspension cylinder as shown.
Typical Example
12. Remove the nut, bolt (1) and two washers (9) from the pin that holds the rear suspension cylinder to the differential housing.
Typical Example
13. Remove pin (11). Remove the rear suspension cylinder from the machine. The weight of the rear suspension cylinder is approximately 666 kg (1470 lb).
Typical Example
NOTE: Bearings (12) are installed in the frame support to prevent frame damage when removing and installing pin (11). If bearings (12) are removed, they will be damaged and cannot be reused.
14. Check the condition of bearings (12). If bearings (12) are worn or damaged, use new parts for replacement, use tool (C) to remove and install bearings (12).
Install Rear Suspension Cylinders
Typical Example
1. Fasten a hoist and tool (B) to rear suspension cylinder (8) as shown.
2. Put the rear suspension cylinder in position on the differential housing, and install the pin that holds it in place.
3. Put the rear suspension cylinder in position on the differential housing, and install the pin that holds it in place.
Typical Example
4. Put two washers (9) in position on the ends of the pin, and install bolt (10) and the nut.
5. Remove tool (B) from the bottom of the rear suspension cylinder.
Typical Example
6. Use the hoist to put the top of the rear suspension cylinder in position in the frame. Align the hole in the frame with the bearing in rear suspension cylinder (8). Install the pin (7).
Typical Example
7. Put washers (6) in position in the ends of the pin, and install the bolt (5) and the nut.
Typical Example
8. Install lines (2) on the suspension cylinder.
9. Connect lines (1) and (3) to the suspension cylinder.
10. Remove the two 50 ton screw jacks from beneath the machine.
11. Charge the rear suspension cylinders with oil and nitrogen. See the Systems Operation/Testing & Adjusting Manual, and the topic "Rear Suspension Cylinders, Charging Procedure" for the correct procedure.
Disassemble Rear Suspension Cylinders
NOTE: Photos are of a 785 Truck. The procedure is the same for the 793B Truck.
Start By:
a. remove rear suspension cylinders
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To prevent possible personal injury, make sure all of the nitrogen has been released from the cylinder before it is disassembled. |
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1. Remove the guard from the rear suspension cylinder.
2. Use tool (A), and remove snap ring (1) from each side of bearing (2).
3. Remove bearing (2) from the end of the cylinder.
4. Put the rear suspension cylinder in position on tooling (B) as shown.
Typical Example
5. Remove valve assemblies (4) and plate (5).
6. Remove the bolts that hold manifold (6) to the rod assembly.
7. Remove the O-rings from manifold (6).
8. Remove valve assembly (7).
9. Remove the bolt and spacer (8).
10. Remove the bolts and two cover assemblies (3). Remove the O-rings from cover assemblies (3).
11. Use tool (B) and extend the cylinder.
12. Put stand (10) in position under the rod assembly as shown.
13. Remove bolts (9) that hold the head to the cylinder assembly.
14. Pull the rod assembly and head out of the cylinder assembly with tool (B).
15. Remove ring (11) from piston (13).
16. Remove nuts (12) and piston (13) from the rod assembly.
17. Remove ball (14) from the rod assembly.
18. Use tool (B) to push head (16) into the cylinder assembly until four 5/8" - 11 NC x 6" (152.4 mm) bolts (17) can be installed.
19. Install four bolts (17) to hold head (16) to the cylinder assembly. Pull rod assembly (15) away from the head with tool (B).
20. Fasten a hoist and tool (C) to head (16). Remove four bolts (17) and remove the head from the cylinder assembly. Head (16) weighs approximately 52 kg (114 lb).
21. Remove O-ring seal (22) and ring (21) from the outside of the head.
22. Remove wiper (18), seal (19) and seal (20) from the inside of the head.
Assemble Rear Suspension Cylinders
NOTE: Photos are of a 785 Truck. Procedures are the same for a 793B Truck.
| NOTICE |
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Seal (19) is yellow and must be installed toward the outside (atmosphere side) of the head. Seal (20) is black and must be installed toward the inside (pressure side) of the head. |
1. Put seals (19) and (20) in position in the groove in head (16).
2. Install wiper (18) in head (16). Install the wiper with the lip toward the outside (atmosphere side) of the head.
3. Make sure the cylinder assembly is fastened securely to tooling (B).
4. Fasten a hoist and tooling (C) to head (16). Put the head in position on the cylinder assembly, and install four 5/8" - 11 NC x 6 in. (152.4 mm) bolts (17), to hold it in place.
5. Put clean oil on the wiper and seals in head (16).
6. Use tooling (B) to push rod assembly (15) into head (16). Remove four bolts (17), and separate the head from the cylinder assembly with tooling (B).
7. Install O-ring seal (22) and back-up ring (21) in the groove on the outside of the head. Put clean oil on the O-ring seal and ring.
8. Put ball (14) in position in the rod assembly.
9. Put piston (13) in position on the rod assembly, and install nuts (12) to hold it in place.
10. Install ring (11) on the piston.
11. Use tooling (B) to push the rod assembly and piston into the cylinder assembly.
12. Install bolts (9) to hold the head to the cylinder assembly.
13. Make sure the O-ring seal is in position in cover assemblies (3) and install the cover assemblies on the head.
Typical Example
14. Install bolt and spacer (8).
15. Install valve assembly (7).
16. Install the O-rings in manifold (6).
17. Install manifold (6) on the rod assembly.
18. Install plate (5) and valve assemblies (4).
19. Use tool (A) to install snap ring (1) in one side of the rod end.
20. Install bearing (2) in the rod end.
21. Install snap ring (1) in the rod end with tool (A).
22. Install the guard on the rear suspension cylinder.
End By:
a. install rear suspension cylinders