The right hydraulic oil ensures smooth lifting, protects the pump and cylinders, reduces heat buildup, and minimizes wear and tear.
This guide explains everything you need to know about dump truck hydraulic fluid, what it is, how to choose the right type, the best viscosity grades, and five high-quality oils available.
Dump Truck Hydraulic Fluid
1. Mobil DTE 25 (ISO 46)
A premium anti-wear hydraulic oil ideal for dump trucks operating in moderate climates.
Features:
- ISO 46 viscosity is suitable for most dump truck hydraulic systems
- Excellent anti-wear performance for high-pressure pumps
- Strong thermal and oxidation stability
- Fast air release to reduce foaming
- Good water separation characteristics
2. Mobil DTE 24 (ISO 32)
A lighter-viscosity hydraulic oil recommended for colder climates or equipment requiring ISO 32.
Features:
- ISO 32 viscosity ensures smooth cold-weather operation
- High oxidation stability for long service life
- Designed for precise hydraulic control
- Effective wear protection for mobile hydraulic equipment
- Maintains fluid cleanliness and filterability
Related Hydraulic Oil Equivalent Chart(For All Brands)
3. Valvoline Multi-Purpose Tractor/Hydraulic Fluid
A versatile hydraulic fluid suitable for heavy-duty machinery, including some dump truck systems.
Features:
- Designed for hydraulics, transmissions, and wet brake systems
- Strong anti-foam and anti-wear protection
- Stable in high-heat, high-load environments
- Typically sold in large pails ideal for fleet service
- Good rust and corrosion protection
4. Mag 1 Heavy-Duty Hydraulic Oil (ISO 68)
A heavy-viscosity hydraulic fluid ideal for extremely hot climates or heavy lifting cycles.
Features:
- ISO 68 viscosity for maximum load-bearing protection
- Designed for older or heavily used hydraulic systems
- Excellent anti-wear additives for long pump life
- Good foam control and air release
- Strong thermal stability for high-temperature operation
5. Mobil Delvac Hydraulic Oil
A robust, high-performance hydraulic fluid formulated for demanding on-road and off-road environments.
Features:
- Engineered for mobile hydraulic systems in trucks and heavy equipment
- Strong anti-wear film strength under extreme pressure
- High resistance to sludge and varnish formation
- Excellent water separation and anti-foam performance
- Available in pails for fleet-level maintenance
Related Hydraulic Symbols Chart(All Symbols + Meanings)
What Is Dump Truck Hydraulic Fluid?
Dump truck hydraulic fluid is a specially formulated oil designed to power hydraulic systems that control the lifting and lowering mechanism of the dump bed. It does more than transfer power; it also lubricates internal components, cools the system, protects against rust and corrosion, and helps remove contaminants.
Because dump trucks operate in dusty, high-load, and high-temperature environments, the fluid must handle extreme cycles and pressure fluctuations without breaking down.
Key Factors When Choosing Hydraulic Fluid for a Dump Truck
1. Viscosity Grade (ISO 32, 46, 68)
The viscosity grade is one of the most important factors.
- ISO 32: For cold climates and lighter-duty systems.
- ISO 46: Most common grade for dump trucks in moderate climates.
- ISO 68: Best for high heat, heavy loads, and older systems with looser tolerances.
2. Anti-Wear (AW) Technology
Dump trucks frequently use AW hydraulic fluid, which protects pumps, valves, and cylinders from wear caused by high-pressure operation.
3. Thermal and Oxidation Stability
The fluid should resist breakdown even under constant cycling and high temperatures. High stability means fewer deposits, cleaner components, and longer oil life.
Related Hydraulic Fitting Size Chart(For All Component Types)
4. Demulsibility (Water Separation)
Moisture can enter the system from condensation or environmental exposure. A good hydraulic oil must separate from water easily to prevent rust, foaming, and component failure.
5. Foam and Air Release Characteristics
Proper air release prevents cavitation (air bubbles that damage pumps) and ensures smooth hydraulic action.
6. Seal Compatibility
Ensure the hydraulic oil is compatible with the seals used in your dump truck’s cylinders and hoses.
How to Choose the Right One for Your Truck
1. Follow the Manufacturer’s Recommendations
Always check the dump truck’s manual for the required ISO grade and type. This should be your primary guide.
2. Consider Climate Conditions
- Cold climate → ISO 32
- Moderate → ISO 46
- Hot climate or heavy loads → ISO 68
3. Avoid Mixing Fluids
Different hydraulic oils can react badly when mixed, leading to seal damage, foaming, or reduced lubrication.
4. Inspect Regularly
Check fluid color, clarity, and level routinely. Darkening, burning smells, or foam means it’s time to change the oil.
Related Kubota UDT Hydraulic Fluid Equivalent Chart(For All Brands)
Dump Truck Hydraulic Maintenance Tips
- Keep the hydraulic reservoir sealed when not in use
- Replace filters at the recommended intervals
- Watch for leaks around hoses, cylinders, and seals
- Sample and test fluid periodically for contamination
- Warm up hydraulics in cold weather to avoid pump damage
FAQs
What hydraulic fluid should I use in a dump truck?
Most dump trucks use AW (Anti-Wear) hydraulic oil in ISO viscosity grades 32, 46, or 68, depending on climate and manufacturer specifications. ISO 46 is the most common choice for moderate temperatures. Always follow the truck or pump manufacturer’s recommended viscosity and specifications.
Should I use 46 or 68 hydraulic oil?
Use ISO 46 for normal to cool temperatures and typical dump truck operation.
Use ISO 68 if you operate in hot climates, perform heavy lifting cycles, or have older hydraulic systems that benefit from a thicker oil film. Temperature and load are the key deciding factors.
What is the difference between AW32 and AW46 vs AW68?
The main difference is viscosity:
- AW32: Thin, flows well in cold weather
- AW46: Medium viscosity, best for most dump trucks
- AW68: Thick, ideal for hot temperatures or heavy loads
All three contain anti-wear additives, but they differ in flow characteristics at operating temperatures.
Related Hydraulic Oil vs Engine Oil(Complete Side by Side Differences)
What is ISO 46 hydraulic oil used for?
ISO 46 is widely used in mobile hydraulic systems, including dump trucks, skid steers, excavators, loaders, and industrial hydraulic equipment. It offers a good balance of flow, lubrication, and heat resistance, making it suitable for most climates.
Can you mix ISO 32 and ISO 46 hydraulic oil?
While they will blend without causing an immediate reaction, mixing viscosities is not recommended. The final mixture may not meet the required viscosity for your system, which can cause sluggish performance or increased wear. Only mix in an emergency and replace with the correct grade as soon as possible.
What are the four types of hydraulic fluid?
The four main types are:
- Petroleum-based (mineral) hydraulic oil – Most common for dump trucks
- Synthetic hydraulic fluids – High performance in extreme temperatures
- Water-based fluids – Fire-resistant applications
- Biodegradable hydraulic fluids – Environmentally friendly options for sensitive areas
Final Thoughts
Choosing the right hydraulic fluid for your dump truck is essential for reliable lifting performance, long component life, and reduced downtime. The five oils listed above are proven, high-quality options suitable for most dump truck hydraulic systems.
Always match the oil to your truck’s recommended viscosity and operating environment for the best results.
