All cars require five basic fluids that need periodic replacement
- engine oil;
- transmission oil (also called gearbox oil);
- antifreeze;
- power‑steering fluid;
- brake fluid.
For each component and unit there is a recommended fluid replacement interval. It is not always necessary to replace everything during scheduled maintenance: the power‑steering fluid, the antifreeze, and the transmission oil. We always follow the vehicle manufacturer’s recommendations. But we also pay attention to changes in fluid colour or low level; such factors can signal an upcoming failure.
And the last but no less important fluid for the car is the windshield‑washer fluid. This one is probably the simplest: we look at the outside temperature, choose the appropriate fluid and fill the reservoir. Refill as needed.
Engine Oil Change
It is important to understand that during operation of an internal combustion engine (ICE) fuel residues and combustion products, wear particles from moving parts, and in cases of severe wear – metal shavings and other contaminants – get into the lubricating material. All this degrades the properties of engine oil and over time it loses its characteristics and cannot perform its functions fully. That is why timely oil changes are essential.
If the engine oil is not changed for a long time, the engine can be “killed”. We will explain how to change engine oil, what the replacement interval is, and why a new oil filter is installed.
Changing the oil in engines of different cars does not differ much and follows the same procedure. First, select the appropriate oil according to the catalogue or the vehicle manufacturer’s recommendation. Then warm the engine to operating temperature. If warmed, proceed with the change immediately. Place the car on a lift and position a special container to collect the used fluid. The second option, if lifts are occupied, is on the inspection pit, where there is a special “tray” oil collector. Then unscrew the drain plug on the engine’s oil pan. Usually this is the lowest point on the pan or, for greater certainty, refer to the service manual. Unscrew the plug with a wrench, and finish by hand, because the oil pours out immediately and quickly (place a container for draining in advance), otherwise you will lose the drain plug. The oil drains quickly, usually no more than five minutes. But 100 % of the oil does not drain, which is not a problem, as typically about 2–3 % of the old fluid remains in the engine.
Should the manufacturer’s recommendations be followed? For modern engines, when oil quality improves, the vehicle manufacturer recommends replacement every 10–15 thousand kilometres. This figure is defined by the manufacturer under ideal operating conditions. The worse the conditions, the faster the oil degrades and the sooner it needs to be changed. What is considered severe conditions? These include frequent temperature changes, frost, frequent engine loads (e.g., in mountainous terrain or when transporting heavy loads), motorsport also does not help preserve durability. Usually, if driving conditions are defined as severe, the mileage before replacement is reduced by 25–30 percent. Urban driving is equivalent to severe – stop‑and‑go traffic stresses the oil as much as off‑road, mountain driving or motorsport. It should also be understood that it is better to consider the oil‑change interval in engine hours. In the city the mileage is low, but the engine runs for a long time. Average replacement intervals for severe urban use: 5,000 – 7,000 km.
Is it necessary to change the oil filter? Yes, absolutely. Working with a worn and clogged oil filter is equivalent to operating without one, because a “bypass” valve opens and oil passes around the filtering element, washing away dirt from the clogged element along the way. This is built into its design so that with thick cold oil the paper filtering element does not rupture. By the end of the engine oil’s service life it will be clogged, leading to the bypass valve opening and oil flowing unfiltered. This results in accelerated engine wear.
Our service station has all the necessary conditions for a quality oil change in modern cars. We also have a large assortment of “top” manufacturer lubricants in stock. We have a set of all required specialized tools for removing oil filters.
Transmission Oil Change
Changing transmission oil is one of the most discussed and controversial topics among car enthusiasts. There are several opposing opinions on when to change the oil in a transmission and how to do it correctly. To make the right decision, it is necessary to understand what functions these lubricants perform and how their replacement affects the performance and service life of the transmission.
Our experts identify four main functions of oil in a transmission.
- Lubricating. Since the gears of the transmission are constantly meshed, a substance that reduces their friction is needed. Oil makes the engagement smooth and the parts wear more slowly. The oil carries away metal shavings from friction elements, which could act on the metal as an abrasive.
- Protective. Transmission oil forms a kind of protective film that shields components from corrosion and oxidation. The unit operates for a long time without failure.
- Cooling. During vehicle operation, the temperature at the gear mesh can reach 250 °C. The oil does not heat above 150 °C, meaning the components transfer excess heat to it.
- Hydraulic function. This is more typical for automatic transmissions, robotic transmissions. It also appears in active differentials such as Haldex. Transmission oil performs the direct work of compressing friction packs to transmit torque.
Changing the oil in the transmission of modern cars is often not mandated by the manufacturer, however, continuous vehicle operation leads to wear of even the toughest parts of the machine, regardless of brand.
At 100,000–150,000 km mileage, fine metal particles from natural wear of gears and bearings fill the fluid. Thus, the physical properties of the oil change, its thermal conductivity increases and its lubricating properties deteriorate. The “mechanical” design does not include a special filter, so the “dirt” remains in constant motion inside the gearbox, increasing wear.
The result of continuous oil heating can be the formation of foam inside the unit. A foamed oil mixture with wear product contaminants loses its lubricating and protective properties, which is especially dangerous for an automatic transmission. At the moment of critical oil contamination in the “auto”, engine torque simply ceases to be transmitted, depriving the vehicle of the ability to move. The answer to the question of whether the transmission oil needs to be changed is quite obvious in this case.
Oil Change Interval
The oil change schedule for a manual transmission (MT) can be found in the vehicle’s technical documentation. Unfortunately, manufacturers often do not consider it necessary to write about this in the manual. In this case, you should listen to the advice of professionals. Experts recommend changing the transmission oil every 100The oil change schedule for a manual transmission (MT) can be found in the vehicle’s technical documentation. Unfortunately, manufacturers often do not consider it necessary to write about this in the manual. In this case, you should listen to the advice of professionals. Experts recommend changing the transmission oil every 100,000 km of mileage or every 7 years of standard vehicle use, whichever comes first. If your car is subjected to frequent loads and the operating conditions leave much to be desired, the oil should be changed every 60,000–70,000 km. The interval also depends on the type of oil and the vehicle class.
Types of Oils and Their Usage Specifics
All transmission oils differ by type and application. Each transmission type has its specialized oil.
For example, a manual transmission uses 75W90 transmission oil, which can be found in most gearboxes and differentials. However, many modern MT manufacturers have moved from “colored” synchronizers to friction ones, and 75W90 is no longer suitable; such MTs require DCTF. The same applies to differentials: if a differential has an LSD lock, the oil must be appropriate. Automatic transmissions usually use the ATF line of oils, the abbreviation standing for Automatic Transmission Fluid – this is the fluid for automatic gearboxes. For CVT continuously variable transmissions, and for dual‑clutch robotic transmissions, DCTF is used.
When considering oil types, a vehicle owner should know that the composition characteristics intended for manual transmissions differ significantly from those of automatic transmission oil. They cannot be substituted for each other.
How We Change Transmission Oil
Changing the oil in the gearbox is recommended in autumn or winter. It is during this period that the unit experiences the highest load and a high probability of failure. An urgent oil change is also needed for newly purchased used cars with mileage over 60,000 km.
Assume the car is at the service station and the engine oil has been changed. If not, place it on a lift or equipped inspection pit.
With manual transmissions and reducers there is no particular difficulty, we drain the old oil through the drain hole. Inspect the magnet, if present on the drain plug, for metal suspension. Through the filler hole we pour the required volume according to the service instruction or catalog of new oil. The filler hole is not always a sight glass for level. If the filler hole is absent, we pour the new oil through the drain hole, all equipment for this is available.
With automatic transmissions it’s a bit more complicated. Each hydraulic‑mechanical, CVT, or robotic gearbox (they all belong to automatic transmissions) has its own procedure. It is very important to know and follow it. Our specialists will select the appropriate oil and the required replacement kit (filter, gasket) for it. The drain‑and‑fill method changes only about 30 % of the oil, and to replace it completely requires knowledge and specialized equipment. For a full oil change we have a special stand that we integrate into the cooling system and, by a displacement method, replaces all the oil. However, you need to understand which gearboxes can be changed this way and which cannot. In some automatic gearboxes, oil change means removing the pan, cleaning and checking for metal particles on the magnets and replacing the filter, sometimes there are two.
In most cases with a serviceable automatic transmission, it is sufficient to partially replace the oil by opening the pan and changing the filters. There is no need to force out the old oil.
It should be remembered that such units are very sensitive to their level. Moreover, overfilling the oil in an automatic affects the transmission just as negatively as underfilling.
It is crucial to set the oil level in the automatic transmission correctly, so start by checking the transmission fluid level in the automatic gearbox.
For this, the gearbox needs to be warmed up (drive the car about 10–15 km), then place the vehicle on a level surface (do not shut off the engine), let the engine run for about 5 minutes at idle, for 3–5 seconds in turn engage the main AT modes, shift the selector to P (on some cars to N, check the manual) and pull out the AT oil dipstick. Then the dipstick is wiped with a clean lint‑free cloth, reinserted firmly for a couple of seconds and pulled out again.
In normal condition the dipstick reading should be midway between COLD and HOT. The main thing is that the readings must not be higher than the HOT mark. It is also not permissible for the ATF level to fall below the COLD mark.
Note that if you rely on the reading when the AT oil has not been pre‑warmed, the data will be inaccurate. As a result you may make a mistake and overfill the AT, because with heating the transmission fluid expands and thins. However, some gearboxes are checked cold.
Please note that the dipstick location can vary between vehicles. Also not all transmissions have a dipstick; there may be a sight plug.
Replacement of Coolant (Antifreeze)
Coolant continuously circulates through the cooling system to collect and transfer the heat generated by the running engine. If this system does not operate correctly, the power unit will overheat, which can lead to severe wear and serious failures. For example, an overheated engine may seize, resulting in costly and complex major repairs.
Antifreeze is the common name for automotive fluids that cool and do not freeze at low temperatures. However, the beneficial properties of modern formulations are not limited to that. Their composition includes complex additives that protect surfaces from corrosion, scale formation, and foaming. Every motorist should know how often antifreeze needs to be changed and how the replacement should be performed. The answers to these questions are found below.
1. Overheating that hinders normal engine operation
The normal operating temperature of the engine ranges between 85–90 °C. Clearances and materials of the power unit are designed for this range. Overheating leads to a loss of power while fuel consumption increases. Insufficient cooling deforms the rings and cylinders. Increased clearances cause exhaust gases to enter the oil or lubricant in the exhaust manifold. If the ICE regularly operates above the specified temperature range, its service life is reduced by roughly 2–3 times.
2. Corrosive impact
The cooling fluid contains water. It is water that transfers heat, not antifreeze. Water in the cooling fluid begins to provoke oxidation processes. To reduce the effect, modern antifreezes contain additives, but they lose their properties over time. Corrosion not only destroys the surfaces of the main line and radiator. It reduces the flow capacity of the channels and increases resistance. The corrosion layer has a lower thermal conductivity, which reduces the efficiency of the cooling system. All this creates extra load on the engine and heat‑dissipating equipment.
3. Sediment precipitation
This problem is characteristic of silicate‑based antifreezes. Over time, some substances in their composition precipitate as a sediment of very fine silicon particles. During fluid circulation, the movement of these hard components creates a significant abrasive effect.
4. Cavitation erosion
Cavitation is understood as the natural process of bubble formation from gases in heated liquid. When these cavities collapse, a significant amount of energy is released, creating excess pressure in the vehicle’s cooling system. Moreover, the collapsing bubbles damage metal surfaces, leading to leaks. The new antifreeze contains special additives that minimize cavitation processes. However, over time the properties of the additives are lost.
Now any doubt should be dispelled that the quality and condition of the cooling fluid must be monitored regularly.
How often should antifreeze be changed in a car?
Many motorists ask themselves this question. But there is no universal correct answer for all cases. Experienced specialists even advise not to rely entirely on the vehicle manufacturer’s recommendations. The regulations provide average guidelines that do not take into account operating conditions and the quality of service maintenance.
Whether a coolant replacement is needed and how often to change antifreeze depends not only on the car make, but also on its mileage and the type of formulation used. Approximate intervals indicating after how many kilometres a new coolant should be added.
G11 class antifreezes. These are traditional antifreezes with an inorganic composition. They usually contain a large amount of additives and are suitable for older car models or engines made of aluminum, cast iron and aluminum alloys. At what mileage should they be changed? Approximately every 50–60 000 km.
G12 class antifreezes. These are carboxylate formulations with organic additives. Their base is ethylene glycol, but the additives contain carbonic acid. Such substances should be replaced every 120 000 km.
Hybrid formulations. These may include G12 category antifreezes with varying numbers of pluses. Organic and inorganic substances are mixed, making the product a hybrid. They are more efficient compared to traditional or carboxylate formulations because they combine the best qualities of both. Their replacement interval can be from 90 to 120 000 km of mileage.
Low‑glycol formulations. They are most often labeled as G13 class antifreezes, as they differ fundamentally from others in composition. The base of such coolants is propylene glycol. They are safer for the vehicle’s system, therefore they are also called low‑hybrid. Some G12++ antifreezes also belong to the low‑glycol group. They can be changed infrequently: every 250 000 km.
There are other factors that affect the coolant replacement interval.
- Cooling system wear level: the older it is, and the more corrosion or deposits on the hoses, the more frequently antifreeze should be changed. If you see rust particles in the coolant after draining, you should top up with fresh fluid more often. 30%.
- Vehicle operating conditions: under increased loads or high temperatures the quality of antifreeze in the system decreases. Therefore after a hot season or operating the car under high stress it is advisable to check the coolant.
- Unscheduled top‑up: if you want to use a formulation of a different class or type, regardless of mileage, the old coolant should be drained.
Under normal conditions and when using a quality antifreeze, replacement is required every 90–150 000 km of mileage. However, some motorists cover that distance in just a few years. In such a situation the antifreeze replacement interval will change. For low mileage you should follow the intervals specified by the coolant manufacturer, as they determine how long the formulation will retain its properties. Depending on the production technology, automotive coolant can be used for 2–5 years.
How we change antifreeze
First we review the vehicle’s technical documentation. It always specifies the optimal replacement intervals for fluids, as well as important nuances of the process itself. Most often the service procedure follows the algorithm below.
Selection of the appropriate coolant. If a concentrate was chosen, it must be diluted in the required proportion with distilled water.
The vehicle is placed on a work position. All subsequent manipulations can begin after the engine has cooled. This requires at least 30 minutes after engine shutdown.
Under the radiator a pan or other container is placed to collect the spent coolant. Then the drain plug is removed. Now the remaining coolant must be poured out from the expansion tank. This may require a flexible hose or removal of the tank. Unscrew the drain plug from the engine block, if present.
If the fluid has not been changed for a long time, it is better to flush the cooling system using special formulations or distilled water.
After that, the new antifreeze is poured in. How much to add? It is best to follow the mark in the expansion tank. After replacing the antifreeze, you should monitor the temperature sensor indicator for a while. Perform several heating and cooling cycles of the engine, topping up as needed. Check the heater’s operation (it draws heat from the engine cooling system). Verify the level in the expansion tank and the replacement can be considered complete. We recommend checking the coolant level each time you open the car hood.
* It is advisable to combine the antifreeze replacement with a timing drive (GRM) service. In this case the engine is partially disassembled and the cooling pump is often replaced. The pump is the lower point of the engine; removing it allows draining almost all the old fluid.
Brake Fluid Replacement
Brake fluid is a vital service fluid, whose quality directly affects your safety. Thanks to brake fluid, the force applied to the brake pedal is transmitted through the lines to the braking mechanisms, ensuring the vehicle stops. Untimely replacement of brake fluid, accompanied by degradation of its properties, can lead to brake system failure and consequently cause accidents. For example, worn fluid can “boil” during intensive driving and the brakes will fail.
To ensure effective brake system operation, you must monitor the condition of the brake fluid. During vehicle operation, brake fluid tends to change its properties, notably absorbing moisture, separating, and oxidizing. According to many manufacturers’ recommendations, brake fluid should be changed at least once every two to three years, depending on mileage or service interval. We recommend focusing primarily on the moisture content of the brake fluid rather than mileage. It should not exceed 3.5%. This is checked with a special device available at the service.
The higher the moisture content, the lower the brake fluid’s boiling point, which can lead to vapor lock (boiling) and brake system failure. If the device shows moisture above 3.5%, it signals the need to replace the brake fluid. If you do not have a measuring device, the fluid quality can be assessed visually – a dark, heterogeneous fluid with sediment indicates replacement. And if, for example, you purchased a used car and do not know when the last service was performed, it is best to replace the brake fluid immediately.
Before replacement, our specialists select the optimal fluid for your usage. For everyday cars, DOT4 or DOT5 is used; for sports cars, a more robust fluid is employed. For example:
We perform the replacement on a lift with all wheels removed. Inspect brake hoses for cracks. Clean and develop the bleed fittings. Carry out the replacement by displacement method (classic) or with a special vacuum device. For some brake systems, the electronics (ABS, ESP) must be put into service mode.
Power Steering Fluid Replacement
The power steering assist (hereafter PS) is one of the most important vehicle control components. Introduced in the 1940s, this type of assist is successfully used in modern cars, easing steering effort.
The PS system requires periodic service. To prevent failure of the pump and steering rack seals, it is recommended to replace the PS fluid every 40–50 thousand kilometres.
First, we determine which type of fluid is required for your vehicle. Usually, the fluid type is indicated on the cap of the power steering reservoir.
Common types: PSF – POWER STEERING FLUID, Dextron – also ATF for automatic transmissions, HF – Hydraulic Fluid.
In normal condition the fluid is light, fairly transparent and does not have a burnt smell. Replacement is required in case of fluid contamination.
Dirty fluid accelerates wear of components in the power steering, especially the steering rack. Due to dirt, foreign noises may appear and the steering wheel feel becomes very stiff. If necessary, the expansion tank should be cleaned or even replaced. It should be noted that the service life of each of the mentioned fluids directly depends on the operating regime as well as the age and mileage of the vehicle.
We use two replacement options, partial and full.
For a partial replacement we remove the power‑steering fluid reservoir cap and remove the filter screen, if present. Using a syringe we completely suction the fluid remaining in the barrel. With the wheels lifted we turn the steering wheel left‑right to push out the old fluid from the steering rack. We fill new fluid up to the upper level on the dipstick. We circulate the new fluid through the system and set the level.
For a full replacement we remove the power‑steering fluid reservoir cap and remove the filter screen, if present. Using a syringe we completely suction the fluid remaining in the barrel. We replace the reservoir with a new one, or if possible clean the existing one. We connect the hoses that go to the reservoir to a special test bench and fully flush the entire system with new fluid. With the wheels lifted we turn the steering wheel left‑right to push out the old fluid from the steering rack. This procedure is required when repairing the steering rack or replacing the power‑steering pump.
