- Mini Hydraulic Excavator:
- 301.6C (S/N: JBB1-UP)
- 301.8C (S/N: JSB1-UP)
- 302.5C (S/N: GBB1-UP)
Description of Change: A new shim and a new filter gasket are used together in order to improve the seal for the hydraulic filter. The new shim and the new filter gasket seat better than the former parts. The new seal and the new filter gasket provide a more reliable assembly.
The modified plate improves the breathing of the hydraulic tank. The former plate had a plain 80 mm (3.15 inch) inside diameter. In certain circumstances, the plate could prevent the hydraulic tank from breathing correctly. An increase of the positive pressure in the hydraulic tank could cause leaks at the filter gasket, at the shim, and at the sight gauge. The modified plate has two 80 mm (3.15 inch) lands that provide the proper location. The remainder of the inside diameter of the plate has been increased in order to improve the breathing of the hydraulic tank.
Adaptable To: The new 291-4577 Filter Gasket directly replaces the former 278-3355 Gasket in the 241-4083 Oil Filter Gp. The new 291-4578 Shim directly replaces the former 278-3353 Shim in the 241-4083 Oil Filter Gp. Make sure that the new shim and the new filter gasket are used together. The effectivity and adaptability of the new shim, the new filter gasket, and the modified 249-8058 Plate is listed in Table 1. The location of the new components is shown in Illustration 1 and Illustration 2.
| Effectivity Of The Improved 241-4083 Oil Filter Gp | ||
|---|---|---|
| Model | Effectivity | Adaptability |
| 301.6C | S/N:JBB1105 | S/N:JBB1-1104 |
| 301.8C | S/N:JSB2029 | S/N:JSB1-2028 |
| 302.5C | S/N:GBB1750 | S/N:GBB1-1749 |
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| Illustration 1 | g01298322 |
Improved Components For The 301.6C and 301.8C Mini Hydraulic Excavators (1) 291-4578 Shim (2) 291-4577 Filter Gasket (3) 249-8058 Plate | |
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| Illustration 2 | g01298323 |
Improved Components For The 302.5C Mini Hydraulic Excavator (1) 291-4578 Shim (2) 291-4577 Filter Gasket (3) 249-8058 Plate | |
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| Illustration 3 | g01298324 |
Correct Orientation Of The Shim (1) 291-4578 Shim (2) 291-4577 Filter Gasket (3) 249-8058 Plate (4) 8T-7547 Bolts (5) 266-8338 Cap As (A) Breather port (B) Identification mark | |
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| Illustration 4 | g01300313 |
Detail C From Illustration 3 (B) Identification mark | |
Note: A breather is not assembled in breather port (A) for 301.6C and 301.8C Mini Hydraulic Excavators.Make sure that the new shim is oriented correctly. Refer to Illustration 3. Identification mark (B) on the shim must be in line with breather port (A). Tighten two bolts (4) to a torque of 22 ± 1 N·m (16 ± 0.7 lb ft). Tighten cap (5) to a torque of 25 ± 3 N·m (18 ± 2 lb ft).
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| Illustration 5 | g01298325 |
Modifications Of The 249-8058 Plate (D) 6.5 ± 0.4 mm (0.26 ± 0.02 inch) (E) 10 ± 5 mm (0.4 ± 0.2 inch) radius at four places (F) 15 ± 2 mm (0.6 ± 0.08 inch) at two places (G) 84 mm (3.30 inch) diameter | |
For an alternative repair, the 249-8058 Plate can be modified. Refer to Illustration 5.