SEALING-RING 4774907 - Caterpillar

Table 1
Required Tools    
Tool     Part Number     Description     Quantity    
A     4C-4890     Hydraulic Test Fitting Gp     1    
Illustration 1 g00596349
Main Control ValveSome lines have been removed for photographic purposes. (1) Plug (2) Relief valveRemove plug (1) from the tee fitting on the inlet housing of the control valve. Immediately install the hose on the tee fitting. Install the 0 to 28000 kPa (0 to 4061 psi) pressure gauge on the hose.Start and run the engine. With the engine at high idle rpm, completely raise the bowl. Increase engine rpm. Slowly move the lift lever for the bowl to the UP position for no more than 5 seconds. The high reading on the gauge is the pressure setting for the relief valve (2). The correct pressure setting is 17225 + 170 - 0 kPa (2500 + 25 - 0 psi). If the pressure reading on the gauge is not correct, the relief valve must be adjusted.
Illustration 2 g00596351
Relief Valve (3) Locknut (4) Locknut (5) Adjustment screw
Loosen locknut (4) and turn adjustment screw (5) .
Remove locknut 3.
Rotate adjustment screw (5) clockwise for an increase in the pressure setting. Rotate adjustment screw (5) counterclockwise for a decrease in the pressure setting.
Tighten locknut (4) after the adjustment is made.
Test the pressure setting again.
When the pressure setting is correct, install locknut (3) .