- Wheel Loader:
- 990H (S/N: BWX1-UP)
Introduction
This Special Instruction contains information on the repair procedure on the main hydraulic tank on certain 990H Wheel Loaders. If cracks or leakage occurs at the main hydraulic tank weld seams, tank repair will be necessary. Repairing the tank will include installing the 235-1290 Expansion Tank Gp .
Do not perform any procedure in this publication or order any parts until you understand the information that is contained in this publication.
Required Parts
235-1290 Expansion Tank Gp     | |||
Item     | Qty     | Part Number     | Description     |
1     | 1     | 2P-1293     | Locknut     |
2     | 1     | 148-8455     | Union As     |
3     | 1     | 148-8347     | Elbow As     |
4     | 1     | 106-8715     | Elbow As     |
5     | 3     | 4S-4455     | Clip     |
6     | 7     | 8T-4121     | Hard Washer     |
7     | 3     | 8T-4136     | Bolt     |
8     | 1     | 221-3498     | Hose As     |
9     | 1     | 221-3499     | Hose As     |
10     | 1     | 218-4480     | Hose As     |
11     | 2     | 153-6237     | Elbow As     |
12     | 1     | 235-1281     | Expansion Tank As     |
13     | 4     | 8T-4137     | Bolt     |
14     | 1     | 167-1795     | Elbow As     |
15     | 1     | 358-9475     | Breaker Relief Valve As     |
16     | 1     | 8X-9391     | Bracket As     |
17     | 1     | 221-3990 (1)     | Cover As     |
( 1 ) | This component is not part of the 235-1290 Expansion Tank Gp . |
Rework Procedure
Hydraulic Tank Crack Repair
Refer to the following document to reference general welding procedures and guidelines for repairing hydraulic tank cracks on 990H machines.
- Special Instruction, REHS1841, "General Welding Procedures".
Remove the hydraulic tank from the machine. Before performing welding on the inside or outside of the tank, clean the tank of combustible or flammable materials. The repair can be made utilizing SMAW or GMAW.
For the SMAW process:
- Use a 1/8" 7018 low hydrogen electrode. Completely de-slag welds and visually inspect for under-cut, porosity, and visible discontinuities.
For the GMAW process:
- Use an ER70S-3 (for example, Lincoln Electric L-50) electrode, 90AR/10CO2 gas, 27.5 – 29 V, 360 IPM WFS.
Expansion Tank Installation
Follow the below guidelines for the installation of the 235-1290 Expansion Tank Gp on 990H machines.
- Ensure that machine implement is lowered to ground and steering articulation lock is installed.
- Relieve pressure from the implement/brake tank by depressing the plunger on the tank breaker relief valve.
- Relieve pressure from the fan/steering tank by depressing the plunger on the tank breaker relief valve.
- Remove the tank breaker relief valves from the implement/brake tank and the fan/steering tank.
- Remove the 212-8787 Cover As and this component will be replaced with 221-3990 Cover As (17). Reference 234-4920 Platform Group in Parts Manual, SEBP3850 for location.
- Install 148-8347 Elbow As (3) in the fan/steering tank breather port. Install 148-8455 Union As (2) with 2P-1293 Locknut (1) .
Illustration 1 | g03329786 |
- Install 106-8715 Elbow As (4) in the implement/brake tank breather port.
Illustration 2 | g03329844 |
- Install 218-4480 Hose As (10), 221-3498 Hose As (8), and 221-3499 Hose As (9). Use three 4S-4455 Clips (5), 8T-4121 Hard Washers (6), and 8T-4136 Bolts (7) .
Illustration 3 | g03329857 |