John deere 70 excavator has many problems and we can solve it by our own hand. Future john deere could be one of the good manufacturer of construction concrete machinery, but for “old old” version. I found about the problem from a bad experience, so I will share to everyone that have bought this old version in a good shape  , or not.

1. john deere 70 excavator Starting bypass pipe is removed and no oil flow

John Deere 70 Excavator Starting Bypass Pipe Is Removed And No Oil Flow

The Deere 70 Excavator is a new excavator model that is being built at the John Deere plant in South Carolina. It features a unique, high-tech design that includes many features and accessories to help you perform your work efficiently and safely. The starting bypass valve is one of these accessories, as it allows you to start the engine without using any oil. This can be done by removing the starting bypass pipe from the engine.

This article describes how to remove and replace the starting bypass valve on your John Deere 70 Excavator.

Step 1 – Remove the Starting Valve From the Engine

To remove the starter bypass valve, first disconnect the fuel line from the engine and disconnect any other lines or wires that are attached to it. Then remove the bolts that hold it in place. There may be 2 or 3 of them depending on what type of engine you have. Once they are removed, use an Allen wrench to loosen and remove the starter bypass pipe from its mounting bracket on your engine block.

Step 2 – Install a Replacement Starting Valve

You may need to purchase a replacement starting bypass pipe for your John Deere 70 Excavator if yours has been

john deere 70 excavator

2. john deere 70 excavator Signal of the boom, stick, bucket and swing not easy to control

The excavator main components include the foundation, chassis, body, arm, bucket and drive devices. Excavator chassis is the basic frame structure of the whole machine, it is mainly composed by the upper frame, boom cylinder bracket and the lower frame. The upper frame is a box-shaped structure welded by steel plates; The boom cylinder bracket is located between the upper frame and lower frame with three groups of hydraulic cylinders at each side. The lower frame is a box-shaped structure welded by steel plates and beams. The excavator cabin is fixed on the upper frame with bolts. The travel device is installed on the front of lower frame, its components include transmission device, slewing mechanism and track driving device.

Excavator cabin is an important part of excavator. It has a good field of vision and provides proper environment for operators. Extend arm can be extended to increase the scope of work area by extending arm device to improve efficiency.

The hydraulic system mainly includes hydraulic pump, hydraulic valve and oil pipe system which are responsible for providing power for bucket cylinder and arm cylinder to dig soil; Swing motor provide power for slewing mechanism to rotate belly.

This is a normal fault. The following is a summary of the causes and measures for this failure:

1. The controller does not receive a signal from the joystick;

2. The joystick does not send signals to the controller as it should;

3. The error code displayed on the screen is E042

3. When start john deere 70 excavator engine, engine is hard to start

1. Check the fuel supply system, especially the sediment in the filter and the water in the oil, and clean it regularly.

2. Check whether the cylinder has carbon deposit and exhaust system is blocked. If there is carbon deposit in the cylinder, it should be cleaned according to the method of carbon removal; check whether there is blockage of exhaust pipe and muffler.

3. Check whether the diesel engine is flooded, check whether there is excessive oil in the intake manifold, remove excessive oil from intake manifold or adjust oil pressure regulator; if valve clearance is too small or valve leakage, adjust it properly; if valve clearance is too large, adjust it according to specifications; if valve spring breakage, replace new one.

4. Check whether the diesel engine fuel injection pump adjustment is correct, if not adjusted well, adjust it according to specifications; check whether high-pressure oil pump has leakage, if there is leakage phenomenon or high pressure oil pump failure symptoms, replace new one.

5. Check whether the cylinder head bolt loosening or falling off due to long time operation without maintenance; check whether there are air leaks between cylinder head gasket and cylinder block or cylinder head gasket and cylinder head; replace new

4. john deere 70 excavator Engine abnormal vibration

After repairing the oil leakage of the gear pump on the JD70 excavator, it started normally. However, when the engine speed was about 800 rpm, there was a slight vibration. The vibration was not obvious when idling, and there was no abnormal noise in the engine compartment.

The oil pressure is normal, and there is no abnormal sound in the hydraulic pump station. After inspecting all parts of the hydraulic system and finding no problems, the engine was disassembled to check whether there were any problems with the front frame, timing gear cover and so on. After checking all parts of the engine and finding no problems, check again whether there are any problems with the cooling water temperature sensor or oil pressure sensor. After inspection, these two sensors are normal.

There is an interlock circuit between these two sensors: when the cooling water temperature is too high (about 90 degrees), it will start to cut off fuel supply through this circuit; when there is a problem with the oil pressure sensor or its circuit, it will cut off fuel supply. Because this circuit works normally, these two conditions can be excluded from consideration.

5. john deere 70 excavator Steering of the excavator not stable

There are several components in the steering system, which can cause different types of failures. For example, steering valves can fail due to overheating or stickiness of the spool. This will result in poor steering response and unstable movement of the machine.

To fix this problem, you need to disassemble the steering valve, clean it with compressed air and lubricate it with fresh grease. And also check if there is a hydraulic oil leak from the valve hoses.

Another reason for poor machine control could be a malfunction of the hydraulic pump that supplies oil to the whole hydraulic system, including the steering. To fix this problem you will need a new pump.

The last possible cause of problems is trouble in the pilot control circuit. For example, a leaky or clogged filter or hose can cause pilot pressure drop and poor control of the excavator.

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