[Solved!] John Deere Hydraulic System Diagram

john deere hydraulic system diagram

Is your John Deere tractor having issues in the hydraulic system?

Well, that seems to be a tiring hazard as the hydraulic system has a great impact in running the tractor smoothly. But, you have to be very sure about the trouble and therefore, troubleshooting it is a must.

Aren’t worried regarding when should you troubleshoot the John Deere hydraulic system?

Troubleshoot it when you notice the fluid temperature is above 180°F, the performance has deteriorated, and weird noises are heard suddenly.

Now comes the most important part and that is recognizing the hydraulic components. John Deere hydraulic system diagram of a few excellent models with their details. 

Stay till the end to find more exciting info.

What to Check if Your John Deere Hydraulic System Not Working?

The hydraulic system on a John Deere may not work due to diverse reasons. And, without checking them out, you can not come to a conclusion of what step to take next.

For that reason, go through the discussion of what to check if your John Deere hydraulic system not working.

1. Hydraulic Fluid Level

The most common reason behind hydraulic system malfunctioning is the hydraulic fluid level.

Both over and less hydraulic fluid level is regarded as a threat for the mower. When the mower works with less fluid, the system doesn’t respond.

In case of excessive fluid, the system may overheat. That’s why check the fluid level before moving to other facts.

2. Air in the Fluid

Next, you should check the fluid tank and observe the fluid in case any bubbles are visible on it.

Bubbles are an indication that air is present in the fluid and it is a barrier for the fluid. Because air is responsible for making the fluid inefficient even if the fluid is new.

3. Temperature of Fluid

The temperature of hydraulic fluid can tell a lot of things when it goes imbalanced.

Hot hydraulic fluid means the mower is running with contaminated fluid or with less fluid.

In some cases, if the relief valve lets excessive fluid go through it, the fluid temperature can cross the limitation.

4. Water in the Fluid

Water in the fluid is another most important key point to look at.

Through any leakages, water can reach inside and get mixed with the fluid. And, it causes the viscosity of the fluid to decrease.

5. Fluid Hoses

Finally, the last but not the least one is the hydraulic fluid hoses.

It is because if you see fluid not reaching the destination, it could be the hoses that can be clogged or carrying leakages.

If fluid is noticed outside the hydraulic unit, leakages are there for sure.

John Deere 4020 Hydraulic System Diagram

john deere 4020 hydraulic system diagram

In case you have a John Deere 4020, its hydraulic system diagram is explained in this segment.

From the left side, the reservoir or transmission case has connection with other components. The transmission pump is just a bit right of it. From the oil filter relief valve housing, many relations are noticeable.

Above it, differential lock, selective control valve and rockshaft are observed. Just beside the housing, oil filter and brake valve are located. Steering valve, PTO clutch and pressure control valve are on the top.

Beside the accumulator, the main hydraulic pump is seen. At the right corner, the oil cooler is near the reservoir. 

John Deere 1020 Hydraulic System Diagram

john deere 1020 hydraulic system diagram

Don’t look anywhere else for the John Deere 1020 hydraulic system diagram. It is depicted here with the components.

Starting from the left side, it has control valve (1), quick couplers (2), rockshaft (3), lube oil to final drives (4), transmission oil cup (5), transmission drive shaft (6), countershaft (7), differential drive shaft (8), transmission oil pump (9), and intake screen (10).

Moving forward to its other components – transmission oil filter bypass valve (11), transmission oil filter (12), bleed line (13), hydraulic oil reservoir (14), check valve (15), hydraulic pump (16), leak off and bleed line (17), brake valve (18), and power steering (19).

Other parts are surge relief valve (20), oil cooler (21), power steering control valve (22), high-low control valve assy (23), to low brake of high-low shift unit (24), control valve of independent PTO (25), to PTO brake (26), and pressure regulating valve (27).

Rest of its units are to PTO clutch (28), to high clutch of high-low shift unit (29), transmission shift cover (30), and to high-low shift unit (31).

These parts show the pressure of the lines – high pressure oil (32), medium pressure oil (33), low pressure oil (34), and pressure free oil (35).

John Deere 318 Hydraulic System Diagram

john deere 318 hydraulic system diagram

Troubleshooting John Deere 318 hydraulic system is also unavoidable. And, that’s why its diagram is elaborated with the components details.

At the left side, the hydraulic system has hydrostatic transmission (1), output shaft (2), hydrostatic drive motor (3), transmission case drain (4), charge relief valve (5), implement relief valve (6), check valves (7), charge pump (8), and filter (9).

Going up, there is variable hydrostatic pump (10), input shaft (11), steering wheel (12), control valve section (13), fluid metering section (14), steering cylinder (15), drive link assembly (16), steering valve (17), check valve (18), and oil cooler (19).

At the right corner, the components are check valve (20), hydraulic control valve (21), control valve spool (22), and control valve spool with float (23).

The last ones are front hydraulic outlets – right side (24), front hydraulic outlets – left side (25), rockshaft cylinder (26), and rear hydraulic outlets (27).

When to Troubleshoot John Deere Hydraulic System?

Through the hydraulic system, many parts of the John Deere tractor get extra power to run as smooth as it can. The impressive fact is no preset gear is required even for running on rough terrains.

But, anything wrong with it can stop providing all these advantages and your tractor will not run well. For that reason, you have to check the hydraulic system to see where the problem is hiding.

A few signs are here that are effective indications that the hydraulic system needs to be inspected.

Check them out to erase the issues in time.

1. Fluid Temperature Above 180°F

Hydraulic fluid temperature has a limitation and when you encounter it rising above 180°F, it calls for an inspection.

The matter is when the airflow around the hydraulic reservoir is blocked, the reservoir’s fluid gets hot. And, it continues to rise till the airflow is not settled.

2. Deteriorated Performance

Deteriorated performance or not responding in time of the hydraulic system is another notable sign.

Both internal and external leakages in the system are responsible for this. If the hoses are leaking, the fluid may escape from there.

3. Sudden Weird Noises

Hydraulic system works well but weird noises can come all of a sudden while the tractor is on duty. Air getting inside the hydraulic system or getting mixed in the fluid can cause this trouble.

The pump has an inlet and that lets the air come inside. In my opinion, you shouldn’t delay after observing this symptom.

How Much Hydraulic Fluid Does a John Deere 4020 Hold?

Answer: A John Deere 4020 can hold up to 12 quarts hydraulic fluid. But, before the quantity was less and it was only 8 quarts. Luckily, John Deere has upgraded it to 12 quarts. 

Why is My Hydraulic System Not Holding Pressure?

Answer: Hydraulic system not holding pressure is a threatening situation for lawn tractors. When the bearings are worn out and pump shafts are not in good condition, the system will hold less pressure than normal. Any internal injuries can also invite it.

What is the Most Common Problem in a Hydraulic System?

Answer: The most common problem of hydraulic system is the contamination of air along with the water. Due to it, the hydraulic system seems to have difficulties in pumping, delivering fluid and completing the overall tasks.

How Does the John Deere Tractor Hydraulic System Work?

Answer: The John Deere tractor hydraulic system works by transferring the hydraulic oil from the reservoir to the hydraulic cylinder. From there, the piston gets power and lifts the arm.

End Note

On the whole, inspecting the hydraulic system becomes a necessity as it guides in detecting the actual problem. Now that you have the John Deere hydraulic system diagram, you can perform that by yourself.

And, notice the signs of the hydraulic system in need of troubleshooting to catch the error when it is smaller and not affecting the other components.

You would love to take a look:

Scott McFadden

Hi! It's Scott McFadden. I'm obsessed with farming. All my life I grew up around my grandfather and his farmhouse. I cannot put in words how they inspired me to farm. From taking care of cows to looking after our gardens I have learned a lot. It would be a real pleasure if I get to share this with you.

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