770G and 772G Off-Highway Trucks TA2 Technical Inspection: 770G (S/N: ECM1-UP) 772G (S/N: LTS1-UP)

Electrical System

Table 1

Status (1)	Description	Specification	Actual	Comments
	Inspect Battery Cables	Cables between the battery, the starter, and the engine ground must be the correct size. Wires and cables must be free of corrosion. Wires and cables must have cable support clamps in order to prevent stress on battery connections (terminals).
	Battery Test	12.4 VDC or more		Refer to Special Instruction, SEHS7633, "Battery Test Procedure".
	Charging System Test	18 VDC to 32 VDC		Refer to Special Instruction, REHS0354, "Charging System Troubleshooting".
	Electric Starting System Test	12 to 16 V at −23° C (−10° F) to −7° C (19° F)		Refer to Testing and Adjusting, SENR3581, "37-MT, 41-MT, and 42-MT Series Starting Motors".
		14 to 18 V at −7° C (19° F) to 10° C (50° F)
		16 to 24 V at 10° C (50° F) to 27° C (80° F)

( 1 )

N = Normal, M = Monitor, A = Action

Engine

Cooling System

Table 2

Status (1)	Description	Specification	Actual	Comments
	Radiator Pressure Relief (Radiator Cap) (2)	-
	Freezing Point of Engine Coolant	-
	Conditioner Test of Engine Coolant	-
	Belt Tension	-		Refer to Operation and Maintenance Manual.
	Difference between the Upper and Lower Radiator Tank Temperatures	-

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	Test for the pressure that is listed on the cap.

Fuel System

Table 3

Status (1)	Description	Specification	Actual	Comments
	Fuel Pressure	717 ± 241 kPa (104 ± 35 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Lubrication System

Table 4

Status (1)	Description	Specification	Actual	Comments
	Engine Oil Pressure at Low Idle	-
	Engine Oil Pressure at Full Load Speed (1800 rpm)	-

( 1 )

N = Normal, M = Monitor, A = Action

Basic Engine

Table 5

Status (1)	Description	Specification	Actual	Comments
	Engine Speed at Low Idle	650 ± 20 rpm
	Engine Speed at High Idle	2200 ± 10 rpm
	Torque Converter Stall Test Engine RPM	1300 ± 10 rpm
	Cylinder Cutout Test	-		Caterpillar Electronic Technician
	Engine Crankcase Pressure (Blowby)	-

( 1 )

N = Normal, M = Monitor, A = Action

Air Inlet and Exhaust System

Table 6

Status (1)	Description	Specification	Actual	Comments
	Torque Converter Stall Test Boost Pressure	45.3 IN_HG
	Cylinder # 1 Exhaust Temperature (2)	-
	Cylinder # 2 Exhaust Temperature (2)	-
	Cylinder # 3 Exhaust Temperature (2)	-
	Cylinder # 4 Exhaust Temperature (2)	-
	Cylinder # 5 Exhaust Temperature (2)	-
	Cylinder # 6 Exhaust Temperature (2)	-
	Cylinder # 7 Exhaust Temperature (2)	-
	Cylinder # 8 Exhaust Temperature (2)	-

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	Compare the exhaust temperature variance at each exhaust port.

Performance Checks

ReferenceRefer to Testing & Adjusting, UENR1122 for more detail on the following checks.

Operational Checks

Table 7

Status (1)	Description	Specification	Actual	Comments
	Raise the Dump Body	18 seconds
	Front Suspension Group measurement	170 mm (6.7 inch)
	Rear Suspension Group measurement from Pin to Pin	831.76 mm (32.75 inch)
	Toe Out Measurement	50.80 mm (2.00 inch)

( 1 )

N = Normal, M = Monitor, A = Action

Hydraulic System

ReferenceRefer to Testing & Adjusting, UENR1122, "Hydraulic and Braking System" for more detail on the following test.

Service Brakes and Retarder System Pressure - Test

Table 8

Status (1)	Description	Specification	Actual	Comments
	Pressure at Slack Adjuster for Service Brakes (Retarder in OFF Position at Low Idle)	6065 ± 345 kPa (880 ± 50 psi)
	Pressure at Front Pressure Tap for Service Brakes (Retarder in OFF Position at Low Idle)	7000 ± 690 kPa (1015 ± 100 psi)
	Slack Adjuster for Service Brakes (Retarder in ON Position at Low Idle)	5000 ± 690 kPa (725 ± 100 psi)
	Pressure at Front Pressure Tap for Service Brakes (Retarder in ON Position at Low Idle)	0 kPa (0 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Secondary Brake System Pressure Test

Table 9

Status (1)	Description	Specification	Actual	Comments
	Secondary Brake pressure Test (Brakes are not applied, at Low Idle, in the Neutral position)	5033 ± 690 kPa (730 ± 100 psi)
	Secondary Brake pressure Test (Secondary Brakes fully applied at Low Idle, in the Neutral position)	less than 140 kPa (20 psi)
	Secondary Brake pressure Test (Brakes are not applied, engine off, in the Neutral position)	3800 kPa (550 psi) or above
	Secondary Brake pressure Test (Secondary Brakes fully applied at Low Idle, in the Neutral position)	less than 140 kPa (20 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Relief Valve (Hoist Raise, Hoist Lower) - Test and Adjust

Table 10

Status (1)	Description	Specification	Actual	Comments
	Relief Valve Test ((High Pressure) Engine at high idle, Dump bed fully RAISED)	18950 +1000 - 500 kPa (2750 +145 -73 psi)
	Relief Valve Test (Low Pressure) Engine at high idle, Hoist control lever in the LOWER position)	3450 ± 350 kPa (500 ± 50 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Relief Valve (Brake Oil Cooler) - Test and Adjust

Table 11

Status (1)	Description	Specification	Actual	Comments
	Brake cooler relief valve at low idle, hoist control lever in the Float position, while body is in the SNUB position	1725 kPa (250 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Power Train System

ReferenceRefer to Testing & Adjusting, UENR1122, "Power Train System" for more detail on the following test.

Torque Converter Lockup Clutch Supply Pressure - Test and Adjust

Table 12

Status (1)	Description	Specification	Actual	Comments
	Modulating valve for the torque converter lockup clutch test (engine running at 1700 rpm, in the NEUTRAL position with the parking brake engaged)	2068 ± 69 kPa (300 ± 10 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Gear Pump (Power Train Charging) Pressure - Test and Adjust

Table 13

Status (1)	Description	Specification	Actual	Comments
	Main Relief Valve Pressure at high idle in the NEUTRAL Position and Parking Brakes are Engaged. The lockup clutch is deactivated.	3240 ± 69 kPa (470 ± 10 psi) maximum
	Main Relief Valve Pressure at low idle in the NEUTRAL Position and Parking Brakes are Engaged. The lockup clutch is deactivated.	2515 kPa (365 psi) minimum

( 1 )

N = Normal, M = Monitor, A = Action

Transmission Lubrication Oil Pressure - Test

Table 14

Status (1)	Description	Specification	Actual	Comments
	Transmission lubrication Relief Valve pressure in the NEUTRAL position at 700 rpm	20.5 ± 14 kPa (3 ± 2 psi)
	Transmission lubrication Relief Valve pressure in the NEUTRAL position at 2200 rpm	172 ± 34 kPa (25 ± 5 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Transmission Pressures - Test and Adjust

Table 15

Status (1)	Description	Specification	Actual	Comments
	Clutch 1	3100 ± 35 kPa (450 ± 5 psi)
	Clutch 2	1725 ± 35 kPa (250 ± 5 psi)
	Clutch 3	2410 ± 35 kPa (350 ± 5 psi)
	Clutch 4	1930 ± 35 kPa (280 ± 5 psi)
	Clutch 5	3100 ± 35 kPa (450 ± 5 psi)
	Clutch 6	3100 ± 35 kPa (450 ± 5 psi)
	Clutch 7	3100 ± 35 kPa (450 ± 5 psi)
	Transmission System Pressure at 700 rpm	2725 ± 70 kPa (395 ± 10 psi)
	Transmission System Pressure at 1817 rpm	3100 ± 35 kPa (450 ± 5 psi)
2200	Transmission System Pressure at 2200 rpm	3240 ± 70 kPa (470 ± 10 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Steering System

ReferenceRefer to Testing & Adjusting, UENR1122, "Steering System" for more detail on the following test.

Control Manifold (Steering) - Test and Adjust

Table 16

Status (1)	Description	Specification	Actual	Comments
	Main Relief Valve Secondary Steering pressure at high idlePark position	26000 ± 400 kPa (3770 ± 58 psi)
	Backup Relief Valve for Secondary Steering pressure at high idle in the Park position	20700 ± 400 kPa (3002 ± 58 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Piston Pump (Steering, Fan) - Test and Adjust

Table 17

Status (1)	Description	Specification	Actual	Comments
	High Pressure Cutoff Valve pressure at high idle	20850 kPa (3024 psi)Minimum
	High Pressure Cutoff Valve pressure at high idle	21550 kPa (3126 psi)Maximum
	Flow Compensator Valve pressure at high idle	2000 kPa (290 psi)Minimum
	Flow Compensator Valve pressure at high idle	3600 kPa (522 psi)Maximum

( 1 )

N = Normal, M = Monitor, A = Action

Hydraulic Fan Drive System

ReferenceRefer to Testing & Adjusting, UENR1122, "Hydraulic Fan Drive System" for more detail on the following test.

Piston Pump (Steering, Fan) - Test and Adjust

Table 18

Status (1)	Description	Specification	Actual	Comments
	High Pressure Cutoff Valve pressure at high idle	20850 kPa (3024 psi)Minimum
	High Pressure Cutoff Valve pressure at high idle	21550 kPa (3126 psi)Maximum
	Flow Compensator Valve pressure at high idle	2000 kPa (290 psi)Minimum
	Flow Compensator Valve pressure at high idle	3600 kPa (522 psi)Maximum

( 1 )

N = Normal, M = Monitor, A = Action

Generator System

ReferenceRefer to Testing & Adjusting, KENR####, "Generator System" for more detail on the following test.

Generator Set - Test

Table 19

Status (1)	Description	Specification	Actual	Comments
	AC Voltage Across Terminals 1 and 2 Half the Rated Speed	Enter Value
	AC Voltage Across Terminals 1 and 3 Half the Rated Speed	Enter Value

( 1 )

N = Normal, M = Monitor, A = Action

Winding - Test

Table 20

Status (1)	Description	Specification	Actual	Comments
	Exciter Armature (Rotor)	Enter Value
	Main Armature (Stator)	Enter Value

( 1 )

N = Normal, M = Monitor, A = Action

Insulation - Test

Table 21

Status (1)	Description	Specification	Actual	Comments
	Main Armature	Enter Value
	Exciter Field	Enter Value

( 1 )

N = Normal, M = Monitor, A = Action

S.O.S

Reference Refer to Operation and Maintenance Manual, SEBU8718, "Maintenance Interval Schedule" for more detail on the following test.

Table 22

Status (1)	Description	Obtain	Comments
	Engine Coolant Sample (Level I)
	Differential and Final Drive Oil Sample
	Engine Oil Sample
	Front Wheel Oil Sample
	Hoist and Brake Tank Oil Sample
	Steering System Oil Sample
	Torque Converter and Transmission Oil Sample
	Engine Coolant Sample (Level II)

( 1 )

N = Normal, M = Monitor, A = Action

MARYGAR

770G and 772G Off-Highway Trucks TA2 Technical Inspection: 770G (S/N: ECM1-UP) 772G (S/N: LTS1-UP) 2012-11-30T18:56:00-08:00 Rating: 4.5 Diposkan Oleh: Unknown