PIN AS 3439249 - Caterpillar

Table 1
Tools Needed    
Tool    Part Number    Part Description    Qty    
A     8T-5320     Hydraulic Test Group     1    
B     9U-6600     Hand Hydraulic Pump     1    
C     3S-6224     Electric Hydraulic Pump     1    The pressure setting of the backup relief valve is 27500 500 kPa (4000 75 psi) at a flow of 8 2 L/min (2.1 0.5 US gpm). Other components in the steering system will keep the pressure from reaching this value. Use a bench test to achieve an accurate pressure test. The backup relief valve must be removed and tested on a test bench before any adjustments.
Illustration 1 g01848035
Steering solenoid and relief valve (1) Inlet port (2) Port to right front steering accumulator (3) Port to right rear steering accumulator (4) Port for the Auxiliary Power Unit (APU) (5) Port to steering control valve (6) Setscrew (7) Nut (8) Backup relief valveA functional test of the relief valve may be performed on the machine.
Remove the hydraulic oil lines from port (2), port (3) and port (5) .
Use Tool (A) to block all three ports.Note: Step 2 prevents the steering accumulators from filling during the test.Note: Port (1) does not need to be blocked. The check valve that is mounted in port (1) prevents oil from flowing back into the pump.
Connect Tool (A) or Tool (B) to port (4). Apply pressure.Note: A pressure reading that is between 25500 to 27500 kPa (3700 to 4000 psi) at a flow of 1.6 L/min (0.4 US gpm) is an acceptable reading. The pump supply cannot produce the necessary oil flow that is required to accurately check the backup relief valve.Use the following procedure to change the pressure setting of backup relief valve (8) :Note: Backup relief valve (8) must be adjusted on a test bench.
Loosen nut (6) .
Turn setscrew (7) clockwise in order to increase the pressure setting.
Turn setscrew (7) counterclockwise in order to decrease the pressure setting.Note: One revolution of setscrew (7) will change the pressure setting by 4730 kPa (686 psi).