You can absolutely replace dot 4 over dot 3 once you purge the old Dot 3 system. You can use dot 4 instead of dot 3 mainly because there’s only a difference in the boiling point between the two.
So, there’s no confusion regarding using dot 4 replacing dot 3. However, one reminder, never use dot 5 just because you can use dot 4 in a dot 3 system. Dot 5 is a completely different thing.
In this blog post, we are going to give you a detail idea about the question above. We have given you an on-to-point answer. But it’s the detail that matters the most.
Contents
Dot 3 Braking Fluid – Details
DOT 3 is a polyethylene glycol-based fluid engineered to withstand extreme temperatures.
This hydraulic fluid boasts a high boiling point, typically around 250°C. Thus the fluid remains effective under intense braking conditions.
Its production involves blending glycerin and alcohol. The mixture is further and supplemented with additives to enhance its performance.
One needs to be extra careful while storing the fluid and utilizing stainless steel, aluminum, or carbon steel containers like iso tanks.
Transportation of DOT 3 brake fluid usually occurs via bulk vessels or tank trucks, with a moderate flammability rating of 1.
It’s widely used in automobiles from both commercial and industrial. Mainly the fluid’s viscosity enables it to transmit hydraulic force through brake lines. As a result, efficient braking at the wheel is possible.
DOT 4 Braking Fluid – Details
DOT 4 brake fluid is a high-performance, non-petroleum hydraulic fluid specially formulated for conventional automotive hydraulic brake and clutch systems. It comprises a complex blend of polyglycol ethers, glycol ether borate esters, and polyglycols. It’s also enriched with corrosion and oxidation inhibitors.
First of all, the impressive boiling point is what makes DOT 4 great. The boiling point is typically around 260°C.
This higher boiling point helps prevent the formation of vapor bubbles at elevated temperatures, ensuring consistent and reliable braking performance over an extended period. It also provides an additional safety margin against vapor lock compared to lower-rated fluids.
DOT 4 brake fluid maintains an alkaline pH level. Thus, it safeguards critical components like cast iron and steel against corrosion.
Its seal swell and lubricity properties aid in preventing fluid leaks and reducing component wear, enhancing system durability.
Due to its exceptional thermal and oxidation stability, it resists fluid degradation. This versatility makes it suitable for various vehicle types. Not just that, there’s no need for multiple brake fluid inventories.
DOT 3 vs DOT 4: What’s the Difference
We are not going for a discussion as a general detail should help you get a clear idea about the difference.
| Characteristic | DOT 3 Brake Fluid | DOT 4 Brake Fluid |
|---|---|---|
| Composition | Polyethylene glycol | Polyglycol ethers, glycol ether borate esters, polyglycols |
| Recommended Applications | Conventional hydraulic brakes and clutch systems where DOT 3 is specified | Conventional hydraulic brakes and clutch systems where DOT 4 is specified |
| Boiling Point (Typical) | Around 250°C | Around 260°C |
| Benefits | – Reliable braking performance – Suitable for a wide range of vehicles – Moderate flammability (Flammability rating: 1) | – Higher boiling point, better performance at high temperatures – Enhanced safety margin against vapor lock – pH-buffered formulation for corrosion protection – Seal swell and lubricity characteristics for reduced leaks and component wear Improved thermal and oxidation stability |
| Compatibility | Suitable for DOT 3 systems | Suitable for DOT 4 systems |
| Corrosion Protection | Basic protection | Enhanced protection |
| Service Life | Standard | Extended |
| Common Uses | Everyday vehicles | High-performance vehicles and applications where increased braking demands are expected |
Things to Consider While Using DOT 4 Instead of DOT 3
You can use DOT 4 instead of DOT 3. However, there are some things to consider such as:
- Check your vehicle’s manufacturer recommendations.
- Ensure the brake system is compatible with DOT 4.
- Completely flush and replace existing DOT 3 fluid.
- Use DOT 4 for high-performance or heavy-duty applications.
- Be cautious not to mix DOT 3 and DOT 4 fluids.
- Monitor for any signs of brake system issues after the switch.
- Consult a mechanic for specific advice if unsure.
Related Readings:
- What Can I Use Instead of Clutch Fluid
- What Can I Use Instead Of Antifreeze
- Can I Use Blue Def Instead Of Adblue
FAQ
Q: Can I use DOT 4 brake fluid as a substitute for DOT 3 in my vehicle?
A: Yes, in most cases, you can use DOT 4 brake fluid as a substitute for DOT 3.
Q: Is it safe to mix DOT 3 and DOT 4 brake fluids in my brake system?
A: Yes, it’s safe to mix DOT 3 and DOT 4 fluid in your braking system. Both are glycol ether based fluid. So, mixing should not be a major concern.
Q: Should I flush my brake system when switching from DOT 3 to DOT 4?
A: Flushing the entire brake system is recommended when switching from DOT 3 to DOT 4 brake fluid to avoid any residual DOT 3 fluid, which can compromise performance.
Q: Can using DOT 4 brake fluid cause damage to my brake components?
A: When used as intended, DOT 4 brake fluid should not cause damage to your brake components.
Q: Are there any temperature-related advantages to using DOT 4 brake fluid over DOT 3?
A: Yes, DOT 4 brake fluid’s higher boiling point can provide better performance and safety at higher temperatures, making it suitable for demanding applications.
Q: What are the potential risks or disadvantages of using DOT 4 brake fluid in a DOT 3 system?
A: The primary risk is compatibility. If not properly flushed and replaced, residual DOT 3 fluid can mix with DOT 4, potentially leading to brake system issues.
Final Verdict
There you have your answer. Just keep the considerations into mind.