Reinforcement of the Hydraulic Oil Tank{5056} Caterpillar

Articulated Truck:

735 (S/N: AWR1-UP)

740 (S/N: AXM1-UP)

740 EJECTOR (S/N: AZZ1-UP)

Introduction

Cracks may develop on the front, left, and right hand side of the hoist and brake system hydraulic oil tank on certain 735 Articulated Trucks, 740 Articulated Trucks, and 740 EJECTOR Articulated Trucks. Inspect the areas that are specified below. Repair the areas that have cracks.

Inspect the Welds for Cracks

Show/hide table



Illustration 1	g01802873

1. The location of the crack in Illustration 1 is approximately 330 mm (13 inches) from the left hand side of the tank.

   Note: The batteries, the circuit breaker panel, and the wiring have been removed for visual clarity.

Show/hide table



Illustration 2	g01805593

2. The location of the crack in Illustration 2 is at the conjunction of the front plate of the hydraulic oil tank and the battery plate. There may be tack welds in this area that may need to be inspected. Not every machine has tack welds in this area.

   Note: The batteries, the circuit breaker panel, and the wiring have been removed for visual clarity.

Show/hide table



Illustration 3	g01806098

3. Inspect the area at the conjunction of the rear plate of the hydraulic oil tank and the left side plate.

Show/hide table



Illustration 4	g01806100

4. Inspect the conjunction of the front plate of the hydraulic oil tank and the right side plate.

Weld Specifications and Qualifications

Show/hide table

Personal injury can result from working with cleaning solvent. Because of the volatile nature of many cleaning solvents, extreme caution must be exercised when using them. If unsure about a particular cleaning fluid, refer to the manufacturer's instructions and directions. Always wear protective clothing and eye protection when working with cleaning solvents.

Show/hide table

Personal injury can result from flame cutting or welding on painted areas. The effect of gasses from burned paint is a hazard to the person doing the cutting or welding. Do not flame cut or weld on painted areas.

Show/hide table

Personal injury or death can result from fumes, gases and ultraviolet rays from the weld arc. Welding can cause fumes, burn skin and produce ultraviolet rays. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing area. Wear eye, ear and body protection before working. Protect yourself and others; read and understand this warning. Fumes and gases can be dangerous to your health. Ultraviolet rays from the weld arc can injure eyes and burn skin. Electric shock can cause death. Read and understand the manufacturer's instructions and your employer's safety practices. Do not touch live electrical parts. See "American National Standard Z49.1, Safety in Welding and Cutting" published by the American Welding Society. American Welding Society 2501 N.W. 7th Street Miami, Florida 33125 See "OSHA Safety and Health Standards, 29 CFR 1910", available from U.S. Department of Labor. U.S. Department of Labor Washington, D.C. 20210

Note: Personal breathing protection should be worn by the personnel that are welding. Personal breathing protection will prevent fumes from entering the lungs of the person that is welding. Use a 1U-8088 Type H Respirator Gp for breathing protection.

Note: Refer to Service Magazine, SEPD0025 July, "Welding on Fuel and Hydraulic Tanks".

Clean the area in order to be welded. Clean the area of the substances that follow:

• Oil

• Grease

• Paint

• Dirt

The tank must be at a minimum temperature of 16° C (60° F) before welding and during welding.

Note: Heat distortion of the base metal is possible when you weld. Avoid excessive heating of the base metal.

Attach the welding ground cable directly to the base metal. Protect machined surfaces from the sparks. Protect machined surfaces from the weld splatter.

Qualifications

All welders must be qualified for the Shielded Metal Arc Welding (SMAW) process in the position that is used for repairing the tank.

Refer to "American National Standards Institute (ANSI)/American Welding Society (AWS) Specification D1.1, or Specification D14.3" for information that regards the qualifications for the SMAW process.

The welders must have used the process at some time within the last six months. The welders must complete the process of certification if the welders have not used the welding procedures for six months.

Proper Welding Procedure on Machines and Engines with Electronic Controls

Proper precautions are necessary in order to prevent damage to electronic controls. When you weld on a machine with electronic controls, use the steps that follow:

1. Turn off the engine. Put the key start switch in the OFF position.

2. If the machine has a battery disconnect switch, open the switch. If the machine does not have a battery disconnect switch, disconnect the negative battery cable at the battery.

3. Connect the ground cable for the welder directly to the actual machine component that will be welded. Attach the clamp for the ground cable as close as possible to the area that is being welded.

   Follow the procedure that is listed above in order to prevent damage from the welding current to the components that follow:

   • Bearings

   • Hydraulic Components

   • Electrical Components

   Note: Do not use electrical components as a ground point for the welder. Do not use ground points for electronic components as a ground point for the welder.

4. Protect wiring harnesses from the sparks. Protect wiring harnesses from the weld splatter.

Specifications

Use the Shielded Metal Arc Welding (SMAW) with E7018 (ANSI/AWS 5.5) welding electrode.

The weld that is deposited by these electrodes will have the following minimum mechanical properties:

An alternative welding process may be used. The Gas Metal Arc Welding (GMAW) process may be used with ER70S-3 (ANSI/AWS 5.18) welding electrode and the manufacturer's specified shielding gases. The weld that is deposited by these electrodes will have the following minimum mechanical properties:

The table that follows shows setting for the welding current of the electrode for shielded metal arc welding that has a diameter of 1.3 mm (0.05 inch).

The table that follows shows the relation between the diameter of the electrode and the approximate current setting.

Note: The settings for the welding current can vary due to the position of the weld. Also, the settings for the welding current can vary with the manufacturer of the welding electrode.

Use a polarity setting of DC reverse polarity. Remove the slag after each pass of the welding electrode. The fast freezing characteristics of electrode for shielded metal arc welding increases the possibility of evolving gas that is trapped in the weld. Control the size of the weld in order to reduce the possibility of evolving gas that is trapped in the weld. The volume of the fillet weld should not exceed 8.0 mm (0.315 inch).

Required Parts

Plate Fabrication

Fabricate the plates from one of the following materials:

• ASTM A572 grade 42.

• ASTM A572 grade 50.

• BS 4360 grade 50B.

Plate 1

Illustration 5	g01807194
(A) 500 ± 1 mm (19.69 ± 0.04 inch) (B) 405 ± 1 mm (15.94 ± 0.04 inch) (C) 394 ± 1 mm (15.51 ± 0.04 inch) (D) 302 ± 1 mm (11.89 ± 0.03937 inch) (E) 296 ± 1 mm (11.65 ± 0.04 inch) (F) 120 ± 1 mm (4.72 ± 0.04 inch) (G) 70 ± 1 mm (2.76 ± 0.04 inch) (H) 125 ± 1 mm (4.92 ± 0.04 inch) (J) 173 ± 1 mm (6.81 ± 0.04 inch) (K) 180 ± 1 mm (7.09 ± 0.04 inch) (L) 183 ± 1 mm (7.20 ± 0.04 inch) (M) 235 ± 1 mm (9.25 ± 0.04 inch) (N) 290 ± 1 mm (11.42 ± 0.04 inch) (P) 338 ± 1 mm (13.31 ± 0.04 inch) (R) 345 ± 1 mm (13.58 ± 0.04 inch) (U) 348 ± 1 mm (13.70 ± 0.04 inch) (V) 393 ± 1 mm (15.47 ± 0.04 inch) (W) 488 ± 1 mm (19.21 ± 0.04 inch) (X) 508 ± 1 mm (20.00 ± 0.04 inch) (Y) 633 ± 1 mm (24.92 ± 0.04 inch) (Z) 653 ± 1 mm (25.71 ± 0.04 inch) (AA) 673 ± 1 mm (26.50 ± 0.03937 inch) (AB) 823 ± 1 mm (32.40 ± 0.04 inch) (AC) 50 ± 1 mm (1.97 ± 0.04 inch) radius in four places (AD) 6 mm (0.24 inch) (AE) 36 ± 1 mm (1.42 ± 0.04 inch) radius in eight places (AF) 30 ± 1 mm (1.18 ± 0.04 inch) radius (AG) 70 ± 1 mm (2.76 ± 0.04 inch) radius (AH) 40 ± 1 mm (1.57 ± 0.04 inch) radius

Illustration 6	g01807633
Section A-A (KK) 55 ± 1 mm (2.17 ± 0.04 inch) (LL) 10 mm (0.39 inch) radius in twelve places

Plate 2

Illustration 7	g01807597
(AJ) 62 ± 1 mm (2.44 ± 0.04 inch) (AK) 88 ± 1 mm (3.46 ± 0.04 inch) (AL) 114 ± 1 mm (4.49 ± 0.04 inch) (AM) 166 ± 1 mm (6.54 ± 0.04 inch) (AN) 218 ± 1 mm (8.58 ± 0.04 inch) (AP) 270 ± 1 mm (10.63 ± 0.04 inch) (AR) 296 ± 1 mm (11.65 ± 0.04 inch) (AU) 322 ± 1 mm (12.68 ± 0.04 inch) (AV) 384 ± 1 mm (15.12 ± 0.04 inch) (AW) 163 ± 1 mm (6.42 ± 0.04 inch) (AX) 326 ± 1 mm (12.83 ± 0.04 inch) (AY) 489 ± 1 mm (19.25 ± 0.04 inch) (AZ) 620 ± 1 mm (24.41 ± 0.04 inch) (BA) 750 ± 1 mm (29.53 ± 0.04 inch) (BB) 55 ± 1 mm (2.17 ± 0.04 inch) radius in four places (BC) 36 mm (1.42 inch) radius in six places

Illustration 8	g01809253
Section B-B (BD) 70 ± 1 mm (2.76 ± 0.04 inch) (BE) 10 mm (0.39 inch)

The thickness of the plate is 6 mm (0.24 inch).

Plate 3

Illustration 9	g01809514
Front view (BF) 113 mm (4.45 inch) (BG) 163 mm (6.42 inch) (BH) 140 mm (5.51 inch) (BJ) 168 mm (6.61 inch) (BK) 240 mm (9.45 inch) (BL) 285 mm (11.22 inch) (BM) 360 mm (14.17 inch) (BN) 538 mm (21.18 inch) (BP) 593 mm (23.35 inch) (BR) 610 mm (24.02 inch) (BS) 643 mm (25.31 inch) (BT) 20 ± 1 mm (0.79 ± 0.03937 inch) (BU) 75 ± 1 mm (2.95 ± 0.03937 inch) (BV) 175 ± 1 mm (6.89 ± 0.03937 inch) (BW) 307 ± 1 mm (12.09 ± 0.03937 inch) (BX) 326 ± 1 mm (12.83 ± 0.03937 inch) (BY) 331 ± 1 mm (13.03 ± 0.03937 inch) (BZ) 350 ± 1 mm (13.78 ± 0.03937 inch) (CA) 20 ± 1 mm (0.79 ± 0.03937 inch) (CB) 4 ± 1 mm (0.16 ± 0.03937 inch) radius in nine places

Illustration 10	g01809753
Top view (CA) 101 mm (3.98 inch) (CB) 90° Angle (CC) 3 mm (0.12 inch)

Illustration 11	g01809754
View C-C (CD) 16 mm (0.63 inch) (CE) 16 mm (0.63 inch) (CF) 32 mm (1.26 inch) (CG) 32 mm (1.26 inch) (CH) 32 mm (1.26 inch) (CJ) 37 mm (1.46 inch) radius in two places (CK) 12 mm (0.47 inch) radius in four places

Procedure for Placing Reinforcement Plates Onto the Machine

Plate 1

1. Remove all dirt, oil, grease, and paint from the area that will be welded.

2. The welds that are cracked in this area will need to be welded. Grind the welds that need to be repaired. Grind the welds flush with the plate. Place the new weld in the areas that are cracked.

Show/hide table



Illustration 12	g01811135

3. Remove the oil level gauge.

Show/hide table



Illustration 13	g01811195

4. Place plate 1 (1) onto the machine. Use the cutout for the oil level gauge to locate the plate properly.

   Note: The hydraulic tank may have bowed. Make sure that the plate is flush against the hydraulic oil tank when this occurs.

5. Weld the plate to the machine with a 4 mm (0.16 inch) fillet weld. The weld should go all the way around the outside of the plate. The weld should also go around the inside of the four vertical slots and go around the inside of the six horizontal pockets.

Show/hide table



Illustration 14	g01811273

Show/hide table



Illustration 15	g01811294
(1) Plate 1 (2) Horizontal pockets (3) 4 mm (0.16 inch) fillet weld (4) Hydraulic tank (5) New weld

6. Add a new weld (5) on top of the 4 mm (0.16 inch) fillet weld (3). The weld should only go on the inside of six horizontal pockets (2) .

   Note: There should not be any starts in the weld and there should not be any stops in the weld.

7. Clean all of the welding spatter from the area of the oil level gauge.

8. Reinstall the oil level gauge with the 150-5939 Adapter . Tighten the screws to a torque of 7 N·m (5 lb ft).

Plate 2

1. Remove all dirt, oil, grease, and paint from the area that will be welded.

2. The welds that are cracked in this area will need to be welded. Grind the welds that need to be repaired. Grind the welds flush with the plate. Place the new weld in the areas that are cracked.

Show/hide table



Illustration 16	g01811336
(A) 70 mm (2.76 inch) (B) 70 mm (2.76 inch) (C) 70 mm (2.76 inch)

3. Place plate 2 (6) onto the machine. Make sure that plate 2 is placed in the location that is shown in Illustration 16.

4. Weld the plate to the machine with a 4 mm (0.16 inch) fillet weld. The weld should go all the way around the outside of the plate. The weld should also go around the inside of the three vertical slots and go around the inside of the six horizontal pockets.

Show/hide table



Illustration 17	g01812021

Show/hide table



Illustration 18	g01812023
(3) 4 mm (0.16 inch) fillet weld (4) Hydraulic tank (5) New weld (6) Plate 2 (7) Horizontal pockets

5. Add a new weld (5) on top of the 4 mm (0.16 inch) fillet weld (3). The weld should only go on the inside of six horizontal pockets (7) .

   Note: There should not be any starts in the weld and there should not be any stops in the weld seam.

Show/hide table



Illustration 19	g01812053
Spot welds

6. The baffle that is welded to the front face of the hydraulic tank is welded with spot welds. Refer to Illustration 19.

Show/hide table



Illustration 20	g01812133

7. Weld the baffle to the front face of the hydraulic tank with a continuous 3 mm (0.12 inch) fillet weld.

Repair of the Plate that Supports the Batteries

1. Thoroughly clean the area around the joint between the plate that supports the batteries and the front plate of the hydraulic tank in order to remove all dirt, oil, and grease from the area.

2. The welds that are cracked in this area will need to be welded. Grind the welds that need to be repaired. Grind the welds flush with the plate. Place the new weld in the areas that are cracked.

Show/hide table



Illustration 21	g01812253

3. Check the area in Illustration 21 for tack welds. When there are no tack welds proceed to Step 6. Proceed to step 4 when tack welds are present.

4. Inspect the tack welds for cracks.

5. The welds that are cracked in this area will need to be welded. Grind the welds that need to be repaired. Grind the welds flush with the plate. Place the new weld in the areas that are cracked.

Show/hide table



Illustration 22	g01812336

Show/hide table



Illustration 23	g01812417

6. Apply a 4 mm (0.16 inch) around the edge of the area that is shown in Illustration 22 and Illustration 23. The weld will need to be applied to the top side of the plate and the bottom side of the plate.

   Note: There should not be any starts in the weld and there should not be any stops in the weld.

Plate 3

1. Remove all dirt, oil, grease, and paint from the area that will be welded.

2. The welds that are cracked in this area will need to be welded. Grind the welds that need to be repaired. Grind the welds flush with the plate. Place the new weld in the areas that are cracked.

Show/hide table



Illustration 24	g01813096

3. Position plate 3 (8) onto the machine. Position plate 3 (8) around the adapter for the hose of the brake pump.

   Note: The hydraulic tank may have bowed. Make sure that the plate is flush against the hydraulic oil tank when this occurs.

4. Weld plate 3 (8) to the machine with a 4 mm (0.16 inch) fillet weld. Weld around the outside of plate three (8). Weld on the inside of the two vertical pockets. Weld around the cutout for the adapter for the hose of the brake pump.

   Note: There should not be any starts in the weld and there should not be any stops in the weld.

Completing the Repair Process

Complete the steps that are listed below in order to complete the repair process.

1. Remove all welding spatter and slag from the areas that were welded on the hydraulic tank.

2. Clean the inside of the hydraulic tank and dry the inside of the hydraulic tank.

   Note: No foreign material should be inside of the hydraulic oil tank.

3. Replace the three 132-8876 Oil Filter Element As in the top cover assembly for the hydraulic oil tank. Reinstall the top cover assembly for the hydraulic oil tank with a new 188-7298 Gasket .

4. Repaint the hydraulic oil tank if it is necessary. Make sure that all orifices are covered.

5. Reinstall the hydraulic tank. Refer to Disassembly and Assembly, RENR5140, "735, 740 and 740 EJECTOR Articulated Trucks Machine Systems".

6. Start the machine and perform a hydraulic systems test. Refer to Systems Operation, RENR5126, "735 and 740 Articulated Trucks Steering, Suspension, and Body Hoist Hydraulic Systems".

7. Check the hydraulic oil tank for leaks.