PUMP GP-INJECTOR 20R1636 - Caterpillar

Performance Inspection
With the wiring connected as shown below, operate the alternator at the specified speed, and adjust the output at the specified current using a variable resistor. The voltage (V) produced must be within 13.5 to 14.3 V on the voltmeter.This measurement should be under the following conditions.1. Use a fully charged battery.2. Temperature must be normal temperature. Alternator output test should be carried out in the method as shown in FIG. 25.
FIG. 25 ALTERNATOR OUTPUT TESTCheck Of Rectifier
To check the rectifier in single, disconnect it from the stator. Two sets of three diodes each are soldered to the respective holder fins.Rectifier trouble is divided in two types: one is an "open" state in which no current flows and the other is a "shorted" state in which current flows in both directions.Use a circuit tester to check the diodes. When checking the positive side diodes, connect the black terminal of the tester to the rectifier lead and the red terminal to the holder fin. If no continuity is found, the diodes are open. Reverse the tester connection, and if continuity exists the diode is shorted.In a similar manner, check the three negative side diodes. To check the negative side diodes, connection of the tester should be reverse of that for positive side diode inspection.
FIG. 26 RECTIFIER CHECKCheck Of Stator Coil
To check the stator coil, it is necessary to disconnect the rectifier wiring if the rectifier is in satisfactory condition. For accurate inspection, however, check the coil as shown in FIG. 27.
FIG. 27 STATOR CHECKFor continuity check, test between either pair of the three leads. For grounding check, test between any one of the leads and the core.Check Of Rotor Coil
Check the field coil as shown in FIG. 28.
FIG. 28 ROTOR COIL CHECK1. Make sure continuity of the field coil exists between slip rings. 2. Make sure no grounding of the field coil exists between the slip ring and the core.Check Of Brush Wear
The top of the brush is beveled. The height of the brush, therefore should be checked at the center of the beveled surface as shown in FIG. 29.
FIG. 29 CHECK OF BRUSH WEAR Check Of Slip Ring
FIG. 30 CHECK OF SLIP RINGUse #400 sandpaper to polish the surface of the slip ring.Check Of I.C. Regulator
To check the I.C. regulator, connect the constant-current source, I.C. regulator, lamp and voltmeter as shown in FIG. 31. Increase the voltage of constant-current source slowly. Check that lamp lights off from 13.5V to 14.5V.
FIG. 31 I.C. REGULATOR CHECKDisassembly
FIG. 32 SEPARATE REGULATOR FROM ALTERNATOR1. Remove two screws (1) and remove regulator cover (2). Separate the regulator from alternator (FIG. 32).
When separating the regulator, lift the regulator up evenly using a screw driver. Do not bend the terminal.
FIG. 33 SEPARATE REAR & DRIVE ASSEMBLIES2. Remove three through bolts. Insert the screwdriver into the notches of drive end frame. Separate the alternator into the rear and drive assemblies by tapping the end frame with a wooden hammer while