Can You Restore the Rubber with Brake Fluid? Here’s What We Know

Rubber has a shelf life. Without reaching that point, it is subject to damage from other circumstances. There are many ways of dealing with damaged rubber. Some of the solutions are homemade and do-it-yourself-friendly. Rubber restoration recommendations usually involve applying substances like alcohol and wintergreen oil, ammonia, glycerin, lye, transmission fluid, and brake fluid.

However, with many homemade tips, not all are competent at solving the problems they are recommended for. This feature focuses on the commonly recommended rubber restoration method involving brake fluid. We want to determine if you can use brake fluid to restore rubber. If you should use it, how? Also, we would like to know if there are better alternatives to using brake fluid to restore rubber.

Restoring Rubber with Brake Fluid, Is It Possible?

Wear and tear and age can damage rubber. As rubber ages, it becomes harder and brittle as the plasticizers that allow it to remain soft dries up. Exposure to harsh substances or weather can also deteriorate rubber’s appearance and structural integrity. Seals made from rubbers become tough to install and cause sealing issues due to inadequate flexibility.

One way to deal with damaged rubber is to replace it. If you ask us, you should replace bad rubber as much as possible. However, repairing or restoring the product could be more cost-effective and environmentally sustainable. Restoring a rubber product can help preserve an item of historical, financial or sentimental worth that would otherwise lose value. Lastly, restoring rubber can increase its performance capability regarding flexibility, grip, elasticity, and resistance to damage.

One often-cited way of restoring rubber is to apply brake fluid to it. Brake fluid is a hydraulic fluid that is crucial to the functioning of hydraulic brakes and clutches in automotive machines such as cars and motorcycles. It helps to transfer force to pressure and is vital for magnifying brake force. In addition, brake fluid helps lubricate the parts of a brake. Also, the brake helps stave off braking system corrosion.

The preceding paragraph is about brake fluid’s primary use. Despite its common recommendation for such, brake fluid does not help restore rubber. Some people have come to think brake fluid is a great way to restore rubber due to some softening and swelling effects it can have on rubber. However, the swelling and softening of rubber are not the same as rubber restoration.

Rubber restoration is re-establishing the flexibility, durability, strength, and structural appearance of a rubber that has lost those properties. Rubber restoration is possible, and there are some ways to do this. However, brake fluid is not one of them. Using brake fluid to restore rubber is a bad idea for several reasons, including:

1) Brake Fluid Can Make Rubber Crack

Because of its chemical composition, brake fluid can crack or brittle rubber. Brake fluid contains glycol- or silicone-based compounds, which can negatively affect rubber. Initially, when brake fluid touches rubber, it can cause it to swell and stretch. Yet the rubber will lose its elasticity and break apart as time passes.

That time could be just a few hours. This can cause catastrophic failures in machines that utilize such rubber. Some rubber types react more adversely to brake fluid than others. So, depending on your rubber type, the cracking effect may be minor or severe.

2) Brake Fluid Is Capable of Breaking the Molecular Structure of Rubber

In a process known as polymer degradation, the molecular structure of rubber can disintegrate when exposed to brake fluid. Brake fluid is a strong solvent. As such, the chemical reaction between brake fluid and rubber can break down the chains of polymer molecules in the rubber. This process can change the rubber material’s shape, color, molecular weight, tensile strength, flexibility, and overall integrity. Again, some rubbers are more susceptible than others.

3) Brake Fluid Can Be Dangerous

Brake fluid is for hydraulic systems and is not to be mishandled. Attempting rubber restoration with brake fluid can expose you to harmful effects without caution. Brake fluid can be hazardous if ingested or inhaled. Also, it has corrosive properties that may damage other materials beyond just the rubber. Furthermore, brake fluid is flammable. While many processes can be harmful, taking such risks with an ineffective procedure is futile and irresponsible.

We would offer some safety precautions for working with brake fluid. But that will be irrelevant since brake fluid is not a good tool for restoring rubber.

Effective Strategies for Restoring a Rubber

Now that we have discounted and discouraged the use of brake fluid, we should offer alternative methods for restoring damaged or worn-out rubber. Below are strategies and materials that you can use to bring your rubber back to life.

1) Cleaning

Before restoring rubber, clean it thoroughly of all debris and grime. You can use a dedicated rubber cleaning solution or soap and water. Use a rubber solvent like turpentine or naphtha to remove paraffin if possible.

2) Heating

You can restore the flexibility of rubber by exposing it to heat. One way is to put your rubber (if it fits) into an oven for around 10 minutes at 100 degrees Fahrenheit. Alternatively, you can set the rubber in boiling water. Remove the rubber from the water with a tong every five minutes to check its condition and flexibility. You can also use a hair dryer to heat the rubber. A heat gun will also work. Just make sure you do not idle in one spot.

Heat will help hardened rubber regain its flexibility. You may need to vary the amount and length of rubber exposure depending on the type of rubber. Also, be careful when heating. Too much heat can melt the rubber.

It will be mindful for you to know that while heat will restore flexibility to rubber, it will reduce its life span.

3) Wintergreen Oil

Wintergreen oil is a natural and strong solvent that you can use to restore rubber. Wintergreen oil can make rubber soft and pliable. It is reasonably affordable and effective in restoring and protecting rubber. In addition, wintergreen oil is safe for both the environment and people. Wintergreen oil has astringent effects on rubber and will tighten and prevent brittle.

Before using wintergreen oil, clean the rubber. Dab oil on a clean cloth and rub it all over the rubber. Then, leave the oil to dry. Apart from that, you can also soak the rubber in wintergreen oil. Soaking the rubber in wintergreen oil may be more effective. However, wintergreen oil can become too expensive if you need to soak a large rubber item. Be careful not to apply too much wintergreen oil, which can make the rubber too soft.

4) Almond Oil

Like wintergreen oil, almond oil is a natural oil. Almond oil is an effective and straightforward way to restore the flexibility of rubber. It is also a valuable substance for cleaning away dirt. Proceed with restoring rubber by rubbing almond oil deep into every nook and cranny.

5) Chemical Rubber Restorer

The use of certain chemicals can help restore the quality of rubber. This method is, however, less DIY friendly as these chemicals are not easily accessible and could pose a greater danger than brake fluid when mishandled. Different rubber materials react differently to various chemicals. However, most will soften when soaked in a solution involving isopropyl alcohol and methyl salicylate.

The solution should be 3 parts isopropyl alcohol and 1 part methyl salicylate. Soak the rubber in the solution for at least 24 hours to soften and rejuvenate its structure. Methyl salicylate is an element of wintergreen oil. You can substitute the methyl salicylate with wintergreen oil.

Do not let these products touch your skin. Wear latex gloves at all times when using this solution.

6) Rubber Conditioner

A rubber conditioner is a product you can use to clean, penetrate and restore rubber materials surfaces. Rubber conditioners can protect your rubber from ultraviolet rays, which can harm it. Also, some rubber conditioners can soften rubber that has become hard with time. Rubber conditioners are also a great way to protect rubbers from cracking.

You will easily find rubber conditioners in hardware and auto stores. Check the product description to see the best conditioner for the type of rubber you aim to restore or condition. ArmorAll, WD-40 silicone spray, and 3X seal saver are examples of commercial rubber conditioners you can apply to protect and restore rubber.

Follow the manufacturer’s instructions in applying the rubber conditioner. Clean the rubber before applying the conditioner.


In this article, we examined if brake fluid can restore rubber. Restoring rubber with brake fluid is ineffectual, and we do not recommend using it. Yes, brake fluid can soften and swell rubber. Yet, the chemical compounds and brake fluid composition will likely cause the rubber to crack and brittle with time. In addition, brake fluid can also break down the molecular structure of rubber and negatively affect its properties.

There are alternative methods to restoring rubber that are effective to some extent. You can apply some heat to the rubber to help it regain its flexibility. Also, you can use natural oils like wintergreen and almond for this purpose. Alternatively, use commercial conditioners or an isopropyl alcohol and methyl salicylate mix to restore your rubber. Best still, if you can, replace worn-out or damaged rubbers.