What is car hydraulic oil used for? (2022)

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Car hydraulic oil

An “oil change” is something familiar to anyone who is familiar with automobiles.

However, in most cases, this term only refers to replacing the engine oil. On the other hand, a car has a significantly greater quantity of fluids, the replacement of which must not be neglected.

Car hydraulic oil

In addition to the gear oil and the oil in the differential, hydraulic oil also has a finite lifespan. This article will explain how to change the brake servo and the oil in the power steering system.

Components of power steering systems and how they function

The power steering system is a component that, when activated, makes it significantly simpler to turn the steering wheel.

It was initially designed to be used only by large trucks, but nowadays, utility vehicles are also typically equipped with the feature as standard equipment.

The following is a list of the components that make up a power steering system:

  • Hydraulic cylinder
  • Hydraulic pump
  • Hose system
  • Tank for expansion

In most cases, a belt connected to the engine will be used to drive the hydraulic pump. As soon as this is put into motion, the pressure begins to rise, and the power steering is ready to be used.

A flanged connection connects the hydraulic cylinder directly to the toothed rack that is part of the steering system.

The cylinder will automatically support the movement of the steering wheel in the opposite direction as soon as it begins to turn in the desired direction.

The pressure is high enough to be of some assistance in this respect. On the other hand, it does not possess the strength to initiate a change.

Hydraulic oil is responsible for transmitting pressure, and as long as it is untainted and uncontaminated, the hydraulic system will function faultlessly.

How often should the hydraulic oil be changed?

The color of fresh hydraulic oil is more of a raspberry red, while the color of old hydraulic oil is more of a cloudy brown.

This could be the result of wear, the effects of heat from the engine, or the introduction of foreign bodies.

On the other hand, there are hardly any manufacturers that establish a predetermined change interval by which it is recommended that the hydraulic oil be changed.

As a general rule, it is possible to establish a limit anywhere between 50,000 and 60,000 miles. When this number of miles has been reached, at the very least, the hydraulic oil needs to be checked.

In addition to that, “old oil” (“old oil”) reveals itself most frequently as increasingly loud noises emanating from the hydraulic pump. Additionally, the steering wheel may sway slightly or turn more intensely than usual.

New hydraulic oil additionally safeguards all of the power steering system’s components and extends those components’ useful life.

On the other hand, manufacturers have not developed any standard components or processes because they are not required to make any changes.

When changing the engine oil, it is significantly more challenging to access the oil drain screw and oil filter than to change the hydraulic oil. Both of these components are located in the exact location.

Replacing the timing belt, which has intervals that have also significantly lengthened due to increased usage, is an ideal time to do so.

On most standard automobiles, today’s replacement parts have a lifespan of more than 100,000 miles.

Timing belt replacement can be quickly finished by inspecting or replacing the hydraulic oil.

You might also want to check the operation of the power steering pump while you’re here. It is in good condition as long as it spins slowly and smoothly while making little to no noise.

Performing each step of the hydraulic oil change in order

The following items are required to change the hydraulic oil in your vehicle:

  • Jack lift
  • Chocks for the wheels
  • Loading Stands for Vehicles
  • Suction pump
  • Collection canister
  • A brand new expansion tank
  • Hydraulic oil that is both recent and appropriate
  • An assistant

IMPORTANT: When changing the oil, it is necessary to ensure that the power steering pump does not become dehydrated. In that case, it might just stop working right away.

1. Raise the automobile

You will need to raise the vehicle so that the front wheels are not restricted in their movement. This is of utmost significance for the circulation of air within the power steering system.

To accomplish this, start by using the jack lift, and then proceed to support it appropriately.

IMPORTANT: Only professional car supports should be used. Other options, such as using squared wood, stones, or the lifting jack alone, are exceedingly risky.

Always position the car on the anchor points that were designed for it or that are appropriate. In the worst possible scenario, a bracket that is not positioned correctly can cause the entire body to become misshapen.

The back wheels should be secured using chocks after the front of the vehicle has been elevated.

What is car hydraulic oil used for

2. Drain any used hydraulic oil from the system

It is possible that certain parts will need to be taken apart in order to gain access to the expansion tank. In any case, the waste collection container needs to be placed close to the expansion tank.

This avoids the development of wide routes and the buildup of unneeded dirt inside the engine compartment.

Cans of windshield washer fluid that have been cut in half or old basins can serve as suitable containers. Hydraulic oil is immediately transferred into the collection container after being drawn from the expansion tank using a suction syringe.

A syringe that is appropriate for use with oil and fuel should cost about 25$ and be readily available.

3. Remove any remaining quantities by draining them

It is impossible to remove all of the hydraulic oil using the syringe. Because of this, it is necessary to “sacrifice” a few drops of fresh oil to flush out the old fluid entirely from the system. You’re going to require help with this.

First, it is necessary to disassemble the expansion tank all the way down to the hoses. After that, the feed hose is detached and placed inside the collection container. Because it is the thickest, it can be identified very quickly.

The next step is to cover the hole that leads to the inlet with tape or another suitable auxiliary material. The reservoir has just had some new hydraulic oil added to it at this point.

When the handwheel can no longer be turned any further, the helper shifts the engine into gear and starts moving the handwheel alternately from left to right.

It is essential to add fresh oil consistently since the hydraulic pump draws in fluid at an instantaneous pace.

If this is not done, the pump runs the risk of drying up, which must be avoided at all costs. The vehicle’s engine is turned off as soon as the container containing the fresh raspberry red oil is reached.

It is now time to flush the hydraulic system, so get started on that right away.

4. Replace the expansion tank with a new one

The expansion tank has a filter that is placed there permanently and cannot be taken off. As a result, the expansion tank must always be completely replaced anytime a component of an assist hydraulic system is repaired.

TIP: Replace the expansion tank’s existing screw terminals with new ones, then cut the supply and outlet hoses on the tank located below the nozzles.

Hoses have a propensity to leak and can lose their tension at points of compression. Therefore, it is essential to always connect the new expansion tank at a new position when using hoses that have been cut shorter.

There is not a 1:1 correspondence between the cross sections of hoses and nozzles, given that a new expansion tank can be purchased for only 5 to 15 dollars.

Depending on the type of vehicle being serviced, these additional charges for the oil change might be acceptable in specific circumstances.

However, if the hoses already have pores in them, it is in the best interest of the business to replace them. Hoses that are porous or fractured leak more frequently, which can have disastrous consequences.

TIP: Examine the hoses to see if there are any signs of rodent bites. They leave a mark consisting of two holes, which makes them easy to recognize.

It is imperative that immediate action be taken in the event that a rodent has made its home in the engine compartment.

They can be permanently eliminated through the use of an ultrasonic device in conjunction with a comprehensive engine flush.

5. Add hydraulic oil

Finally, add fresh hydraulic oil. While the assistant pours oil into the engine, the engine is restarted, and the steering wheel is turned in a constant back-and-forth motion between the two sides.

The hydraulic system will be vented as a result of this action. When the oil in the expansion tank reaches its maximum level, you should stop adding more. After unscrewing the cap, it is lifted and positioned over the expansion tank before being lifted once more.

On the integrated dipstick, you will be able to view the current oil level. It ought to be at “full,” or as close to that as possible. On the other hand, the hydraulic system should not be at its maximum capacity.

In the event that the maximum level is reached, use the syringe to withdraw a small amount of oil at a time until the ideal level is reached.

TIP: Always make sure to use the appropriate type of hydraulic oil. The necessary information can be found on the certificate of registration for the vehicle or in the operating instructions.

The use of the incorrect oil can cause the hoses to deteriorate from the inside, which can lead to serious consequences.

Always make your purchases based on the volume of the filling. Because of the length of time between changes, it is not practical to use large containers because they are less expensive.

The cost of a liter of hydraulic oil ranges anywhere from 10 to 50 dollars.

The repercussions of using hydraulic oil that has seen better days

The use of contaminated oil in the hydraulic system is detrimental to all of the system’s components.

Particles in the oil flow cause significant wear and tear to the vehicle’s components, most notably the power steering pump.

The microparticles tend to accumulate in the seals, which eventually causes them to become worn out. A malfunctioning pump for the power steering reveals itself to the observer as a very loud grinding sound.

It is not difficult to replace, but it is costly. The cost of a brand-new power steering pump can range anywhere from 150 to 500$, depending on the manufacturer.

It is possible to significantly extend the service life of the power steering pump at a cost that is affordable by providing it with new hydraulic oil and a replacement expansion reservoir.

Get rid of old hydraulic oil as soon as possible

Old hydraulic oil, like all other lubricants, is a waste product that poses a problem and cannot be disposed of in the garbage or flushed down the drain in the same way.

It is recommended to transfer the used lubricant into the container that was purchased specifically for the new product. After that, you can take it back to the store where you originally bought it.

The dealers are obligated to take it and must have suitable partners to dispose of waste materials professionally.

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