CYLINDER-HYD 9U5049 - Caterpillar

Rework Procedure
Before performing this procedure, the Power Train Electrical System Service Shutdown procedure must be performed to verify that the voltage in the system components is discharged.
Refer to the Troubleshooting, "Electrical Shutdown and Voltage Discharge" section of the manual in order to perform the Power Train Electrical System Service Shutdown procedure.
Before performing this procedure, ensure that the Engine Lockout Control is in the ON position (lock out) and the Battery Disconnect Switch is in the OFF position (battery negative disconnected). Lock and tag both of the disconnects.
Note: This procedure will require manual rotation of the truck engine in order to rotate the Generator Rotating Rectifier Assembly. A manual 279-3473 Barring Device tool or an air powered 329-3831 Barring Group tool should be used to rotate the Engine and the Rotating Rectifier Assembly during this procedure. Install the barring tool according to the installation and operating instructions that are provided with the tool.
Image1.1.1
At the front lower right-hand side of the Generator housing, remove the access cover for the Rotating Rectifier Assembly.
Image1.2.1
One of three connections points that are used to connect the positive lead of one diode, the negative lead of another diode and one exciter armature lug to the rotating plate.
(10) Red positive diode flying lead
(11) Diode base lead connection to the DC rotating plate
(12) Mechanical connection that passes through the insulated hole in the DC rotating plate (the insulation provides electrical isolation from the rotating plate)
(13) White sheathed exciter AC input lead
(14) Black negative diode flying lead
Image1.3.1
Detail view of the hardware that is used to connect a black/blue negative diode flying lead, a red positive diode flying lead, and the white sheathed exciter armature lug to the plate. Three of these connection points are located on the Rotating Rectifier Assembly.
(15) 1/4-20 inch nut
(16) Belleville washer
(17) Flat washer
(14) Black negative diode flying lead
(10) Red positive diode flying lead
(18) White sheathed exciter armature lug
(19) Flat washer
(20) Rotating plate
(21) Flat washer
(22) Belleville washer
(23) 6.4 mm (0.25 inch) x 31.8 mm (1.25 inch) hex head bolt
Image1.4.1
The positive lead of