Hydraulic jacks are so popular that oil manufacturers offer specific hydraulic jack oil, which is available in part stores, car care shops, and even some large supermarkets.
In this article, I will make a quick comparison between these products and regular hydraulic fluid and tell you about the substitute oils that you can find right at home in case of an emergency.
- Jump to: List of Jack Oil Substitutes
But first,
What is Jack Oil? Is it the Same as Hydraulic Oil?
All hydraulic systems follow the same working principles, but their applications, working conditions, mechanisms, and other features differ. Hydraulic jacks manufacturers adopted ISO 22 or ISO 32 hydraulic oil as the best oil to make their products work safely and effectively.
But not all hydraulic oil are suitable for hydraulic jacks. Exclusively designed hydraulic jack oil is conceived to meet the requirements of vehicle jacks. It has additives specially tailored to ensure optimal performance and protect them against corrosion, friction, and other factors, extending their lifespan.
Hydraulic Jack Oil Properties
These products are made to have similar properties to ISO 22 or 32 hydraulic oils, and they are usually semi-synthetic or synthetic oils with a mineral oil base.
Viscosity is measured in grades, and according to the International Organization for Standardization (ISO), higher numbers mean that the fluid is thicker or more resistant to flow. To give you a better idea of how dense these grades are, water at room temperature (20°C) has a viscosity degree of 1.
Jack oil comes in different viscosity grades, so checking your jack’s user manual before buying it is important.
Some hydraulic jack oil brands state that they are compatible with all jacks in the market and probably have a viscosity between 22 and 32. But if you want to be 100% sure, check with your jack’s manufacturer to find out if they recommend that product.
The flash point of hydraulic jack oil is between 150°C (302°F) and 200°C (392°F), which is a little lower than standard hydraulic fluid, but high enough to make it safe to operate.
Additives
The good thing about specific hydraulic jack oil is that the oil and its additives don’t damage the jack’s internal parts but protect them. The additives in the formula are made to lubricate the jacks’ internal moving parts and protect the seals, O-rings, bearings, and other components. Besides, jack oil is made to keep corrosion away and create a thin barrier against friction, reducing the component’s wear and extending the durability of the moving parts.
The special additives are designed to ensure optimal performance, high thermal stability, and prevent foaming. Some manufacturers also offer jack oils with anti-leak properties that have proven very effective in fixing small and medium leaks.
In summary, jack oil is similar to hydraulic oil but has a specific range of viscosity (ISO 22 or 32), and it contains additives for ideal performance.
5 Jack Oil Alternatives
Below, you will find a list of alternative fluids for your vehicle jack. Some are more suitable for extended use than others, which I would only use as a last resource.
1. Power Steering Fluid
I have been using this fluid in my shop’s floor jacks for ages without a problem. I use standard, semi-synthetic power steering fluid because it has a good viscosity index and has anti-foam additives. Besides, hydraulic steerings are pretty delicate, withstand high pressures, and have many rubber components and seals, similar to the floor jacks and bottle jacks. If power steering fluid can work in a sensitive system like hydraulic steering, why not use it for my floor jacks? And it works great.
I must say that when I first used it, hydraulic jack oil wasn’t as popular as today, and power steering fluid was way cheaper and easier to find than the hydraulic fluid my jack’s user manual recommended.
2. Automatic Transmission Fluid (ATF)
ATF can save you in a hurry, but there are many things to consider before pouring it into your car jack. Synthetic and detergent-free products can do a great job, and they have a lot of additives to prevent corrosion, displace water, reduce friction, and much more.
The problem is that high-quality ATF products are pretty expensive compared to hydraulic jack oil.
On the other hand, if you go for the cheaper options, you will end up damaging your jack’s seals and O-rings. Besides, if you use your jack a lot, cheap ATF tends to become foamy, so you should consider how fond of your jack you are before using cheap ATF.
3. Motor Oil
Low-viscosity motor oil, such as 10W or 20W SAE, has a similar viscosity to hydraulic oil.
It’s a good choice because even the cheapest products have enough anti-oxidation, anti-foam, and of course, lubrication properties to keep your car jack in good shape.
The problem is that because of their intended use, they have detergent and dispersant, which is harmful to your jack’s rubber parts.
4. Hydraulic Oil
This may seems like an obvious choice. However, the key thing to notice here is the viscosity of the fluid.
You should only use ISO 22 to ISO 32, or hydraulic oils with an SAE viscosity grade of 5W/10W, preferably with anti-foam property.
High viscosity fluids used in machineries are not suitable for your vehicle jacks.
5. Vegetable Seed Oil
Vegetable seed oil, for example, sunflower, canola, or soy oil, has good viscosity levels to work as a hydraulic oil jack substitute. They are eco-friendly, 100% biodegradable, and non-toxic.
The problem is they don’t have additives to protect the jack from corrosion and wear, and its performance is highly affected by temperature changes, so your jack won’t work consistently.
So, use it in emergency, but replace them with a proper hydraulic jack oil as soon as possible.
There you have it. Five alternative fluids that you can use when you are out of jack oil.
Remember, these substitutes should only be used in the case of emergency and not as long-term solutions. Long-term use of these alternative fluids can harm the hydraulic jack and potentially reduce its life expectancy.
What Not to Use in Jacks?
Not all hydraulic fluids are suitable for jacks. Here are some of the oils you should not use as jack oil.
- Brake Fluid:
Never use brake fluid as a jack oil substitute. It’s thinner than the less viscous hydraulic oil and is made from glycol, which is extremely harmful to the jack’s seals. Besides, nearly all the brake fluid used in the automobile industry are glycol-ether based (not petroleum based), which is not recommended for jacks as it can cause damage. - Extremely Low Viscosity Oils:
Oils with a viscosity lower than 10 don’t have the needed thickness to make jacks work safely and efficiently. - Extremely High Viscosity Oils:
These kinds of oils can fail at the time of releasing the pressure and can leave the jack stuck in the upper position. Never exceed a viscosity higher than ISO40 as a hydraulic jack oil substitute. - Compressor Oil:
The minimum viscosity of compressor oil is ISO 68. As mentioned above, it’s too thick to use in a floor jack and is over the recommended value to ensure safe use. - Cutting Oils:
Cutting oils shouldn’t be mixed with hydraulic oils because they have chemicals that, when combined, could cause a harmful reaction. Even if you remove the old hydraulic fluid, cutting oil is very abrasive and will damage your jack’s moving parts in no time. - Others:
You should not use penetrating oils such as WD40, lubricating oils, highly inflammable oils such as kerosene, etc. in vehicle jacks.
David Castillo is an automotive industry expert specializing in vehicle electronics and stand-alone fuel management systems. He has over 20 years of experience and owns a car repair garage and tuning shop.
David still runs his shop but is now more focused on pre-purchase car inspections and writing for FinePowerTools.