5 Most Common John Deere 333G Problems and How to Fix Them

The John Deere 333G loader is popular among professionals thanks to its efficiency and productivity. It handles multiple tasks like digging, hauling, and grading in the landscaping and construction industry.

Unfortunately, this loader will not last a lifetime without having issues. The most common John Deere 333G problems are starter issues, hydraulic problems, engine losing power, problematic parking brake, and faults from the Diesel Exhaust Fluid (DEF) system.

So, what should you do if these problems plague your loader?  Below we’ll dissect these issues and provide the best available fixes.

Problematic Starter

Starter problems in JD 333G are common in older loader models. The starter is part of the loader’s electrical system and will likely develop issues over time.

Most users confuse this issue with starting problems resulting from faulty fuel systems. If your 333G’s starter is acting up, there are several symptoms you might notice. Some are as follows:

  • The starter engages, but the engine fails to start
  • Starter won’t engage
  • Starter engages slowly

Does your compact loader show these symptoms? If yes, the loader might have problems with the battery, cables, wire harness, or starter motor. Let’s discuss how you should fix starter problems.

How to fix:

Your loader’s battery might have low output voltage if the starter doesn’t engage. Use a multimeter to get the voltage reading.

Inspect the battery connections and terminals for corrosion if you don’t have a low output voltage issue. Disconnect the terminal connectors and check for buildup, grime, or corrosion.

You can remove any buildup with a wire brush, water, and baking soda. Alternatively, go for a battery terminal cleaning product to remove the buildup.

If you have an old battery that won’t hold a charge, install a new one.

The starter motor might be faulty if it engages slowly or engages, but the engine fails to start. First, check for loose or broken connections to the starter. Secure the connections and replace any broken/damaged wires. Consider rebuilding or replacing a defective starter motor.

John Deere 333G Hydraulic Problems

John Deere 333G problems related to the hydraulic system appear in old and new models. With time, the boom and the bucket might fail to work. If the boom doesn’t lift or drop, defective lift controls or the hydraulic pump might be the causative factors.

If the bucket fails, your loader’s bucket controls might be faulty. In some cases, the hydraulic fluid might freeze and cause lifting problems.

Failed in-bar or in-set sensors will also cause the JD 333 G’s hydraulics not to work.

How to fix:

Before considering a complex diagnosis, check the condition of your loader’s hydraulic fluid. Insufficient fluid will cause lifting problems, so fill the reservoir with fresh fluid.

If it appears frozen, run the loader for 15-30 minutes and drain the fluid. Then add fresh, high-quality fluid. You can choose an alternative fluid that won’t freeze despite the cold weather.

If you suspect the loader’s boom and bucket controls are faulty, check if loose connections or damaged wires are to blame. You can tighten the connections and replace frayed/broken wires. If the control system is defective, hire a specialist to rebuild or replace it.

You can also check for failed pressure sensors and replace them before replacing the entire control system.

Engine Losing Power

Some John Deere 333G owners complain that their loaders work for a few hours, and then the engine loses power. If your loader engine bogs down while using it, there might be issues with the fuel system or the air filter.

Fuel system problems that might cause the engine to lose power include clogged fuel lines, leaks in the system, contaminated fuel, or broken injection nozzle.

If the intake has an air restriction problem, there could be clogs in the air filter.

How to fix:

Start by checking the level of fuel in the tank. If the fuel level keeps going down, there could be leaks in the system. Check for the leaking areas and repair them.

Sediments can clog the fuel lines and restrict the fuel from reaching the pump. Drain the old, contaminated fuel and flush a fuel system cleaner to remove the sediments. Then add fresh, new fuel.

Next, check if air restriction results from a dirty/clogged air filter. You’ll need to clean the filter or install a new one if the current one appears old and worn.

Lastly, inspect the fuel injectors and the nozzle. If you find a clogged fuel injector, clean it with an injector cleaner. Replace a broken or burnt injection nozzle.

John Deere 333G DEF System Fault

The JD 333G Diesel Exhaust Fluid (DEF) system can be problematic and cause the loader to throw fault codes such as DCU 523588.07. If the code reoccurs after clearing it, your loader’s DEF system needs thorough attention.

A problematic DEF system will cause increased emissions and reduced engine performance. And like most John Deere 333G problems, a faulty DEF system occurs due to poor maintenance. The most common causes of JD 333G DEF system fault are as follows:

  • Contaminated DEF
  • Leaks
  • Blockage
  • Clogged DEF filter

How to fix:

If you’ve not checked or changed the DEF for a long period, the fluid might have gone bad. Contaminated or dirty DEF will cause excessive emission of smoke from the exhaust. You need to drain the DEF and add a fresh one.

A dirty DEF can also cause blockage issues in the system. Check the operator’s manual or consult a professional to help unblock the DEF system.

Another culprit could be leaking parts in the DEF system. Visually inspect the system and repair or replace the leaking parts.

Lastly, inspect the DEF filter for clogs and clean or replace it as necessary.

Parking Brake Problems

Some John Deere 333G users have reported that the parking brake fails to release or disengage. Moreover, the seat belt lights might remain in the “ON” position after releasing the brake.

In most cases, parking brake issues with this loader originate from the electrical system. The loader may have a malfunctioning wiring, switch, or sensor that fails to send signals.

Besides these electrical issues, a broken spring will cause the jamming of the lock. As a result, the brake fails to release fully. A broken spring will also cause the electrical harness to shorten.

How to fix:

To fix the parking brake problem, remove the seat and safety belt. Then locate the spring and check if it appears broken. 

The brake won’t disengage if there’s a broken spring. So replace the spring. If the wire harness appears damaged, replace it.

If the parking brake issue persists, look for a defective sensor, switch, and solenoid. You can rely on the operator’s manual to locate and fix these components.

Are John Deere 333G Problems a Deal Breaker?

No. John Deere 333G is well known for its reliability, fuel efficiency, and user-friendliness. While the above issues are common in this loader, they’re fixable. You can fix them independently or seek help from a professional mechanic. Keep up with the maintenance schedule to ensure the loader stays in good condition.