- Track-Type Tractor:
- D7R (PIN: 2EN1-UP; 2HR1-UP; 3DN1-UP; 3ZR1-UP; 4SR1-UP; 5KZ1-UP; 5MR1-UP; 6ER1-UP; 9HM1-UP)
Description of Change: The location of the breaker relief valve on the hydraulic tank has been changed. The new location is on the top of the tank. See Illustration 1. The former location was horizontal in the access cover of the tank. See Illustration 2. In the horizontal position, oil in the hydraulic tank could leak out of the relief valve. The vertical position of the relief valve in the top of the tank will prevent the relief valve from leaking oil.
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| Illustration 1 | g00694635 |
New Relief Valve Location in the Hydraulic Tank (1) Test Port | |
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| Illustration 2 | g00694639 |
Former Relief Valve Location in the Hydraulic Tank | |
Adaptable To: The change to the relief valve location can be adapted to earlier machines. The 108-3125 and 140-8484 Hydraulic Tanks can be updated by reworking the 9T-7483 Tank. A 9U-7010 Coupling must be modified and welded on the top of the tank. This weld boss will allow the installation of the 3G-4783 Breaker Relief Valve. A 9S-8008 O-Ring Plug and a 3D-2824 O-Ring Seal must be installed in the former Breaker Relief Valve port in the access cover.
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| Illustration 3 | g00694643 |
Modification of the Hydraulic Tank (A) 147 mm (5.80 inch) | |
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| Illustration 4 | g00694645 |
Modification of the Coupling (1) 9U-7010 Coupling (A) 20 mm (0.80 inch) (B) 43 mm (1.70 inch) | |
The 9T-7483 Tank can be reworked by performing the following steps:
- Cut a hole in the top of the tank that is 25 mm (1.00 inch) in diameter. See Illustration 3.
- Cut off the end of the 9U-7010 Coupling that has the pipe thread. See Illustration 4.
- Locate the weld boss over the hole on the top of the tank.
- Clamp the weld boss on the top of the tank.
- Weld the boss onto the tank with a 3 mm (0.12 inch) fillet weld.
Reference: Service Magazine, SEPD0025, 2 July 1990, "Welding On Fuel and Hydraulic Tanks".
- Clean the welded area thoroughly and clean the inside of the tank thoroughly.
- Pressure test the tank through port (1) with a pressure of 105 ± 35 kPa (15 ± 5 psi).