M312 Wheeled Excavator TA2 Technical Inspection{0372, 1000, 7000, 753T, 7565} Caterpillar

Excavator:

M312 (S/N: 6TL1-UP)

Introduction

Inspections are the most basic form of condition monitoring. Inspections are easy to do and surprisingly effective at helping you spot equipment health issues. Proactive monitoring and analysis of equipment information will allow Dealers to intervene effectively before problems occur.

Note: Before adjusting product settings to comply with listed baseline TA2 values, consult SIS for the latest specification values.

Note: Specification values are based on the following machine settings, unless otherwise stated.

• Engine Speed Dial "10"

• HP Mode

• AESC OFF

• A/C OFF

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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, SENR5816, "Electric Starting System - Test".
		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)	-		Refer to System Operation Testing and Adjusting.
	Freezing Point of Engine Coolant	-		Refer to Operation and Maintenance Manual.
	Belt Tension	13 to 19 mm (0.5 to 0.7 inch)		For alternator, fan, and air conditioner apply 110 N (25 lb) of force midway between the pulleys.
	Conditioner Test of Engine Coolant	92° to 98°C (198° to 176 °F)		Full open temperature. From 3054 Specifications, SENR5815-11.
	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 at HIGH IDLE	42 to 70 kPa (6 to 10 psi)		Minimum pressure is 30 kPa (4 psi).

( 1 )

N = Normal, M = Monitor, A = Action

Lubrication System

Table 4

Status (1)	Description	Specification	Actual	Comments
	Engine Oil Pressure at LOW IDLE	62 kPa (9 psi) minimum
	Engine Oil Pressure at HIGH IDLE	280 kPa (41 psi) minimum for turbocharged engine

( 1 )

N = Normal, M = Monitor, A = Action

Basic Engine

Table 5

"Engine Performance - Test (Engine Speed)"
Status (1)	Description	Specification	Actual	Comments
	Low Idle AEC OFF	1000 to 1050 rpm
	Low Idle AEC ON	1000 to 1050 rpm
	High Idle in Mode II AEC OFF	2130 to 2180 rpm
	High Idle in Mode III AEC OFF	2380 to 2420 rpm
	Minimum Engine Speed at High Idle in Mode III (Load)	1950 rpm

( 1 )

N = Normal, M = Monitor, A = Action

Air Inlet and Exhaust System

Table 6

Status (1)	Description	Specification	Actual	Comments
	Pump Stall Boost Pressure
	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)

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

Performance Checks

ReferenceRefer to Testing & Adjusting, RENR1180, "Operational Checks" for more detail on the following test.

Operational Checks

Swing Speed

Table 7

Swing Speed and Overswing on Level Ground - Check
Status (1)	Description	Specifications (2)	Actual	Comments
	Left Swing	27.5 to 31.5 sec
	Right Swing

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	Time for five complete revolutions..

Cylinder Drift - Check

Table 8

Cylinder Drift Per Minute
Status (1)	Description	Specifications		Actual	Comments
		Pressure
		15000 kPa (2175 psi)	30000 kPa (4350 psi)
	Stick Cylinder	8.0 mm (0.31 inch) (2)	20.5 mm (0.92 inch) (2)
	Bucket Cylinder	6.2 mm (0.24 inch) (2)	23.6 mm (0.93 inch) (2)
	VA Boom Cylinder	3.3 mm (0.13 inch) (2)	9.0 mm (0.35 inch) (2)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	Maximum drift

Cylinder Operating Speed - Check

Table 9

Cylinder Operating Speed (seconds)
Status (1)	Description	Specifications	Actual	Comments
	Boom Extension	4.5 ± 0.5
	Boom Retraction	N/A
	Stick Extension	3.7 ± 0.3
	Stick Retraction	3.3 ± 0.3
	Bucket Extension	3.0 ± 0.2
	Bucket Retraction	2.7 ± 0.3
	VA Boom Extension	4.5 ± 0.5
	VA Boom Retraction	12.5 ± 0.5
	Stabilizer Extension	5.8 ± 0.2
	Stabilizer Retraction	5.2 ± 0.2
	Blade Extension	2.2 ± 0.2
	Blade Retraction	2.4 ± 0.2

( 1 )

N = Normal, M = Monitor, A = Action

Hydraulic System

ReferenceRefer to Testing & Adjusting, RENR1180 for more detail on the following tests.

Pilot System

Relief Valve (Pilot) - Test and Adjust for M312 S/N:6TL1-679

Table 10

Status (1)	Description	Specifications	Actual	Comments
	Pilot Relief Valve	3000 to 3200 kPa (435 to 464 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Relief Valve (Pilot) - Test and Adjust for M312 S/N:6TL680-UP

Table 11

Status (1)	Description	Specifications	Actual	Comments
	Pilot Relief Valve	3100 to 3500 kPa (450 to 507 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Accumulator - Test and Charge for M312 S/N:6TL1-950

Table 12

Status (1)	Description	Specifications	Actual	Comments
	Pilot accumulator gas charge pressure (2)	1000 kPa (145 psi)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	Nitrogen gas pressure varies with the temperature. To obtain the most accurate nitrogen charge, the temperature of the accumulator must be identical to the air temperature around the accumulator. The specification is with an air temperature of 21 °C (70 °F). Refer to Testing and Adjusting, RENR1180, "Accumulator - Test and Charge" for additional charging pressure and temperature relationships.

Accumulator - Test and Charge for M312 S/N:6TL951-UP

Table 13

Status (1)	Description	Specifications	Actual	Comments
	Pilot accumulator gas charge pressure (2)	2000 to 2300 kPa (290 to 330 psi)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	Nitrogen gas pressure varies with the temperature. To obtain the most accurate nitrogen charge, the temperature of the accumulator must be identical to the air temperature around the accumulator. The specification is with an air temperature of 21 °C (70 °F). Refer to Testing and Adjusting, RENR1180, "Accumulator - Test and Charge" for additional charging pressure and temperature relationships.

Pump System

Margin Pressure and Low Pressure Standby - Test and Adjust for M312 S/N:6TL1-679

Table 14

Status (1)	Description	Specifications	Actual	Comments
	Standby system pressure	2500 to 3000 kPa (360 to 435 psi)
	Margin pressure	2000 to 2200 kPa (290 to 320 psi)
	Main pump pressure	32000 to 34000 kPa (4640 to 4930 psi)
	Load sensing signal pressure	30500 to 31500 kPa (4420 to 4565 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Margin Pressure and Low Pressure Standby - Test and Adjust for M312 S/N:6TL680-UP

Table 15

Status (1)	Description	Specifications	Actual	Comments
	Standby system pressure	2500 to 3000 kPa (360 to 435 psi)
	Margin pressure	2000 to 2300 kPa (290 to 330 psi)
	Main pump pressure	32500 to 33800 kPa (4710 to 4900 psi)
	Main pump pressure - Heavy Lift	37000 to 38300 kPa (5365 to 5555 psi)
	Load sensing signal pressure	30500 to 31500 kPa (4420 to 4565 psi)
	Load sensing signal pressure - Heavy Lift	35000 to 36000 kPa (5075 to 5220 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Main Pump (Proportional Reducing Valve) - Test and Adjust for M312 S/N:6TL1-950

Table 16

Status (1)	Description		Specifications		Actual	Comments
			No load	Load
	Main pump pressure (Proportional reducing valve)	Mode I	1200 to 1250 kPa (175 to 180 psi)	-100 bits
		Mode II	1600 to 1650 kPa (230 to 240 psi)	-100 bits
		Mode III	2200 to 2250 kPa (320 to 325 psi)	-100 bits

( 1 )

N = Normal, M = Monitor, A = Action

Main Pump (Proportional Reducing Valve) - Test and Adjust for M312 S/N:6TL951-UP

Table 17

Status (1)	Description		Specifications		Actual	Comments
			No load	Load
	Main pump pressure (Proportional reducing valve)	Mode I	1200 to 1250 kPa (174 to 181 psi)	3100 to 3500 kPa (450 to 507 psi)
		Mode II	1600 to 1650 kPa (232 to 239 psi)	1000 kPa (145 psi)
		Mode III	2200 to 2250 kPa (319 to 326 psi)	-100 bits

( 1 )

N = Normal, M = Monitor, A = Action

Main Pump (Destroke Pressure) - Test and Adjust

Table 18

Status (1)	Description	Specifications	Actual	Comments
	Destroke Pressure (2)	14000 to 16000 kPa (2030 to 2320 psi)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	Use the 123-6471 Diagnostic Tool Gp or the M300 Technician to adjust the constant mode from 1770 kPa (257 psi).

Main Control Valve System

Relief Valve (Main) - Test and Adjust

Table 19

Status (1)	Description	Specifications	Actual	Comments
	Main Relief Valve (implement or travel) (4)	36000 to 37000 kPa (5220 to 5365 psi) (2)
		41000 to 43000 kPa (5947 to 6237 psi) (3)

( 1 )	N = Normal, M = Monitor, A = Action
( 4 )	If the machine is equipped with the "heavy lift option", the correct pressure specification is 40000 to 42000 kPa (5800 to 6090 psi)
( 2 )	for M312 S/N:6TL1-679
( 3 )	for M312 S/N:6TL680-UP

Relief Valve (Signal Limiter) - Test and Adjust

Table 20

Status (1)	Description	Specifications	Actual	Comments
	Signal Limiter Relief Valve pressure	30500 to 31500 kPa (4420 to 4565 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Relief Valve (Signal Limiter Heavy Lift) - Test and Adjust for M312 S/N:6TL680-UP

Table 21

Status (1)	Description	Specifications	Actual	Comments
	Signal Limiter Relief Valve pressure - Heavy Lift	35000 to 36000 kPa (5075 to 5220 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Relief Valve (Line) - Test and Adjust (Travel Motor) - Test and Adjust

Table 22

Status (1)	Description	Specifications	Actual	Comments
	Travel Motor Line Relief Valve	40000 to 42000 kPa (5800 to 6090 psi)
	Transmission shift accumulator gas charge pressure (2)	800 kPa (116 psi)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	Nitrogen gas pressure varies with the temperature. To obtain the most accurate nitrogen charge, the temperature of the accumulator must be identical to the air temperature around the accumulator. The specification is with an air temperature of 21° C (70° F). Refer to Testing and Adjusting, "Accumulator - Test and Charge" for additional charging pressure and temperature relationships.

Relief Valve (Line) - Test and Adjust (Implement) for M312 S/N:6TL1-409

Table 23

Status (1)	Description			Specifications	Actual	Comments
	Line relief valve	Boom Cylinder	Head End (2)	36000 to 38000 kPa (5220 to 5510 psi)
			Rod End
		Stick Cylinder	Head End
			Rod End (2)
		Bucket Cylinder	Head End
			Rod End
		VA Boom Cylinder	Head End
			Rod End	40000 to 42000 kPa (5800 to 6090 psi)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	If the machine is equipped with the "heavy lift option", the correct pressure specification is 40000 to 42000 kPa (5800 to 6090 psi)

Relief Valve (Line) - Test and Adjust (Implement) for M312 S/N:6TL410-679

Table 24

Status (1)	Description			Specifications	Actual	Comments
	Line relief valve	Boom Cylinder	Head End (2)	37000 to 38000 kPa (5365 to 5510 psi)
			Rod End
		Stick Cylinder	Head End
			Rod End (2)
		Bucket Cylinder	Head End
			Rod End
		VA Boom Cylinder	Head End
			Rod End	40000 to 42000 kPa (5800 to 6090 psi)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	If the machine is equipped with the "heavy lift option", the correct pressure specification is 40000 to 42000 kPa (5800 to 6090 psi)

Relief Valve (Line) - Test and Adjust (Implement) for M312 S/N:6TL680-UP

Table 25

Status (1)	Description			Specifications	Actual	Comments
	Line relief valve	Boom Cylinder	Head End	40000 to 42000 kPa (5800 to 6090 psi)
			Rod End
		Stick Cylinder	Head End	36000 to 38000 kPa (5220 to 5510 psi)
			Rod End	40000 to 42000 kPa (5800 to 6090 psi)
		Bucket Cylinder	Head End	40000 to 42000 kPa (5800 to 6090 psi)
			Rod End
		VA Boom Cylinder	Head End	36000 to 38000 kPa (5220 to 5510 psi)
			Rod End	40000 to 42000 kPa (5800 to 6090 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Boom System

Control Valve (Boom Lowering) - Test and Adjust for M312 S/N:6TL1-679

Table 26

Status (1)	Description	Specifications	Actual	Comments
	Lowering control valve pressure	36000 to 37000 kPa (5220 to 5365 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Control Valve (Boom Lowering) - Test and Adjust for M312 S/N:6TL680-UP

Table 27

Status (1)	Description	Specifications	Actual	Comments
	Lowering control valve pressure	40000 to 42000 kPa (5800 to 6090 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Pressure Switch (Overload Warning) - Test and Adjust

Table 28

Status (1)	Description	Specifications	Actual	Comments
	Overload Warning Pressure	16000 kPa (2320 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Stick System

Control Valve (Stick Lowering) - Test and Adjust for M312 S/N:6TL1-679

Table 29

Status (1)	Description	Specifications	Actual	Comments
	Lowering control valve pressure	36000 to 37000 kPa (5220 to 5365 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Control Valve (Stick Lowering) - Test and Adjust for M312 S/N:6TL680-UP

Table 30

Status (1)	Description	Specifications	Actual	Comments
	Lowering control valve pressure	40000 to 42000 kPa (5800 to 6090 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Swing System

Swing Pump Control (Mechanical Zero) - Test and Adjust

Table 31

Status (1)	Description	Specifications	Actual	Comments
	Swing charge pressure (pump)	2000 to 2200 kPa (290 to 320 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Swing Pump Control (High Pressure Cutoff) - Test and Adjust

Table 32

Status (1)	Description	Specifications	Actual	Comments
	Swing cutoff pressure	34000 to 35500 kPa (4930 to 5150 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Swing Brake Pressure - Test

Table 33

Status (1)	Description	Specifications	Actual	Comments
	Swing Brake Pressure	3000 to 3200 kPa (435 to 465 psi) (2)
		3000 to 3100 kPa (435 to 450 psi) (3)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	for M312 S/N:6TL1-679
( 3 )	for M312 S/N:6TL680-UP

Solenoid Valve (Swing Pump Proportional Relief) - Test and Adjust for M312 S/N:6TL1-679

Table 34

Status (1)	Description		Specifications	Actual	Comments
	Swing pump pressure (Proportional relief valve)	Mode I	1000 to 1050 kPa (145 to 150 psi)
		Mode II	1600 to 1650 kPa (230 to 240 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Solenoid Valve (Swing Pump Proportional Relief) - Test and Adjust for M312 S/N:6TL680-UP

Table 35

Status (1)	Description		Specifications	Actual	Comments
	Swing pump pressure (Proportional relief valve)	Mode I	1000 to 1050 kPa (145 to 150 psi)
		Mode II	higher than Mode I pressure by 18 percent

( 1 )

N = Normal, M = Monitor, A = Action

Relief Valve (Swing Charge Pressure) - Test and Adjust

Table 36

Status (1)	Description	Specifications	Actual	Comments
	Swing Charge Pressure	2000 to 2200 kPa (290 to 320 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Relief Valve (Swing Pump) - Test and Adjust

Table 37

Status (1)	Description	Specifications	Actual	Comments
	Line relief valve - Swing	37200 to 39200 kPa (5395 to 5685 psi) (2)
		37000 to 39000 kPa (5367 to 5657 psi) (3)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	for M312 S/N:6TL1-679
( 3 )	for M312 S/N:6TL680-UP

Travel System

Travel Motor (Stall Pressure) - Test and Adjust

Table 38

Status (1)	Description	Specifications	Actual	Comments
	Travel Motor (Stall Pressure)	30500 to 31500 kPa (4420 to 4565 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Travel Motor (Upstroke Pressure) - Test and Adjust

Table 39

Status (1)	Description	Specifications	Actual	Comments
	Travel motor pressure (upstroke)	25000 to 26000 kPa (3625 to 3770 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Transmission (Parking Brake Reserve Pressure) - Test and Adjust

Table 40

Status (1)	Description	Specifications	Actual	Comments
	Parking brake reserve pressure	1150 to 1250 kPa (165 to 180 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Steering and Brake Systems

Accumulator (Wheel Brake Charge Pressure) - Test and Adjust

Table 41

Status (1)	Description	Specifications	Actual	Comments
	Wheel brake accumulator gas charge pressure (2)	4500 kPa (650 psi)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	Nitrogen gas pressure varies with the temperature. To obtain the most accurate nitrogen charge, the temperature of the accumulator must be identical to the air temperature around the accumulator. The specification is with an air temperature of 21 °C (70 °F). Refer to Testing and Adjusting, "Accumulator - Test and Charge" for additional charging pressure and temperature relationships.

Relief Valve (Steering) - Test and Adjust

Table 42

Status (1)	Description	Specifications	Actual	Comments
	Steering pressure	18000 to 19500 kPa (2610 to 2830 psi)

( 1 )

N = Normal, M = Monitor, A = Action

Work Tool Systems

Relief Valve (Medium Pressure Function) - Test and Adjust

Table 43

Status (1)	Description	Specifications	Actual	Comments
	Line relief valve	20000 to 22000 kPa (2900 to 3190 psi)
	Relief valve	17000 to 18000 kPa (2460 to 2610 psi) (2)
		17000 to 18500 kPa (2460 to 2680 psi) (3)

( 1 )	N = Normal, M = Monitor, A = Action
( 2 )	for M312 S/N:6TL1-679
( 3 )	for M312 S/N:6TL680-UP

S.O.S

ReferenceRefer to Operation and Maintenance Manual, SEBU6933, "Maintenance Interval Schedule" for more detail on performing S.O.S samples.

Table 44

Status (1)	Description	Obtain		Comments
	Engine Oil Sample
	Engine Coolant Sample (Level II)
	Hydraulic Oil Sample
	Swing Drive Oil Sample
	Right Final Drive Oil Sample
	Left Final Drive Oil Sample

( 1 )

N = Normal, M = Monitor, A = Action