ENGINE AR 4W6271 - Caterpillar

Personal injury or death can result from machine articulation or movement. Machine frames can move and a person can be crushed.Connect the steering frame lock between the front and rear frames before working on the machine.
Personal injury can result from hydraulic oil pressure and hot oil.Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.Make sure all of the work tools have been lowered to the ground, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.
Sudden movement or accidental starting of the machine can cause personal injury or death to persons on or near the machine.To prevent personal injury or death, perform the following:Park the machine on a smooth, level surface.Lower the work tool to the ground and engage the parking brake.Stop the engine and remove the key.Block the wheels and install the steering frame lock.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Install the steering frame lock.
Release the pressure from the hydraulic system.ReferenceRefer to Systems Operation, Testing and Adjusting, "System Pressure - Release".
Illustration 1 g01264834
Location of the float sequence valve
Illustration 2 g01265231
(1) Fitting (2) Hose assembly (3) Float sequence valve
Disconnect hose assembly (2) from fitting (1). Install the 5I-3190 Fitting, 2R-6806 Connector and 6V-3965 Fitting As to fitting (1) .
Connect hose assembly (2) to the 2R-6806 Connector .
Connect the 177-7861 Hose As and 8T-0855 Pressure Gauge to the 6V-3965 Fitting As .
Illustration 3 g03689981
(4) Lift arm positioner switch (5) Ride control switch
Move lift arm positioner switch (4) to the OFF position. Move ride control switch (5) to the OFF position.
Start the engine.
Use the bucket and lift arms to raise the front of the machine off the ground.
Observe the pressure gauge while moving the joystick control lever to the FLOAT position. The float sequence valve should open at 1930 70 kPa (280 10 psi). The front of the machine will return to the ground when the float sequence valve opens.Note: If the front of the machine returns to the ground before the FLOAT position is selected, the float sequence valve pressure setting is too low.
Stop the engine.
Illustration 4 g01265233
(3) Float sequence valve (6) Locknut (7) Adjusting screw
To adjust the float sequence valve, loosen locknut (6). Turn adjusting screw (7) clockwise to increase the pressure or counterclockwise to decrease the pressure. Tighten the locknut.
Repeat Steps 7 through 11 until the pressure setting is correct.
Lower