Shop Talk Blog

The Official Blog for Texas Final Drive

Hydraulic Fluid Questions for Newbies

by Dr McCaslin | Oct 18, 2017 |

Hydraulic System, Hydraulics



In this Shop Talk Blog post, we are going to discuss some questions about hydraulic fluid that are for people new to hydraulics. We've tried to track down some practical answers to very common real-world questions, like whether hydraulic fluid will kill grass, and what to do when hydrualic fluid gets on asphalt.

Will hydraulic fluid kill grass?


Undiluted hydraulic fluid has a bad reputation for killing grass, and rightly so. To make matters worse, if it soaks into the ground it can kill new grass when the lawn is reseeded. The best solution is to dig out the contaminated soil and replace it. Some people may try cleaning the grass off with Dawn dish washing liquid (which is great for cleaning up hydraulic fluid), but that only disperses the hydraulic fluid over a wider area and doesn’t do anything about its effect on the soil.  Try to avoid hydraulic fluid spills on soil and vegetation.

Will hydraulic fluid damage asphalt?

The answer is yes. Untreated oil stains (including hydraulic fluid) will begin to dissolve the binder that holds the asphalt together, which will weaken it severely. According to GP Maintenance Solutions, you should pursue one of the following courses of action after a spill, all of which begin with mopping up as much of the spill as possible:

  • Spread cat litter over it and firmly pat it down, leave overnight, sweep it up the next day, and finally rinse with water
  • Pour a couple of cans of Coke on the spill, leave overnight, rinse with water the next day
  • Use an oil-stain remover, following manufacturer's instructions

Can hydraulic fluid freeze?

Cold temperatures can cause hydraulic fluid to gel, but it will not freeze like water does. When it does thicken, however, you need to allow it to warm up before trying to work with it as you would under normal circumstances. The gel can be so thick that it really won't flow, which is the whole point of hydraulic fluid.

Will hydraulic fluid damage paint?

Fortunately, the type of hydraulic fluid used in construction equipment does not typically damage paint. If you get it on, say, your truck, you’ll of course want to wash it off. Most people recommend using concentrated Dawn dish washing liquid to remove it from your vehicle.


How do you get hydraulic fluid out of clothes?

You can find advice all over the web about how to get hydraulic fluid out of clothes, and suggestions include things like Simple Green, WD-40, Dawn dish washing liquid, and Resolve. The best approach involves the use of a degreaser on the problem spots (assuming your clothes weren’t totally drenched in hydraulic fluid) followed by laundering your clothes as you normally would. If the stains persist, soak your clothes overnight in a mixture of oxygen bleach, with a small amount of laundry detergent mixed in. Then, launder again.


Why does hydraulic fluid turn milky?

According to Hydraulics & Pneumatics, hydraulic fluid that looks milky has been contaminated with water. On a similar subject, if your hydraulic fluid looks foamy, then air has entered the hydraulic system. Both of these are bad for your hydraulics, but there are ways to remove contaminants from your hydraulic fluid.  Your next concern would be determining how the air or water got into your hydraulic system.


We hope you found the answers to these questions about hydraulic fluid helpful. If you ever have a question about hydraulic motors and final drives, feel free to contact us! We'd love to help you out.  And, if you have any questions you'd like to see us cover in the blog, please leave a comment below.


Texas Final Drive is your partner in providing new or remanufactured final drive hydraulic motors from a single mini-excavator to a fleet of heavy equipment. Call today so we can find the right final drive or hydraulic component for you, or check out our online store to find your O.E.M. manufacturer brand motor now. 

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Topics: Hydraulic System, Hydraulics

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