Skip the auto shop - Our mechanics make house calls

Q: What does flushing car fluids mean?

asked by on

What does flushing car fluids mean?

A: Flushing car fluids generally refers to hav...

Flushing car fluids generally refers to having a sealed systems fluid completely replaced usually with the use of a machine that is capable of complete fluid exchange. Systems that are generally flushed in our modern vehicles include the coolant system, brakes system automatic transmission, engine, power steering system, fuel injection system, and sometimes even the AC system.

This process is generally done with the use of a machine designed to remove the original fluid in the system, pass fresh fluid or a cleaner through the system and replenish the proper fluid when finished. Flushing can also be done on fuel system lines in the event of a contaminated fuel system. This helps to remove the old fluid which may have lost its lubrication or other properties and removes scale, dirt, and debris, which can affect proper operation and cause further damage. Flushing the system to remove debris would be similar in concept to clearing a partially clogged drain. Using the pressure to force the dirt and old fluids out of the system and replenishing the vital new fluid will help to ensure proper operation and extend service life. For example, coolant over time becomes acidic and corrosive and turns into an electrolyte. Along with losing the lubrication properties which help to keep seals soft and prevent rust and scale, this chemical change can cause actual engine damage to the cylinder walls, head surface, water pump or radiator. In the case of the transmission, the fluid provides the pressure needed to apply the internal clutches for gear selection and lubricates to protect from dirt and wear. Over time, due mostly to heat, these additives will break down and the fluid will lose its ability to protect the internal parts. Flushing restores the fluid and cleans the system. Think of it like a detox cleanse when starting a diet. The key to any vehicle’s long life and lower cost of overall operation is proper maintenance. Flushing should be a vital part of this process.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car will start but will not go into drive or reverse. It revs up just fine, transmission was not slipping. Rear tire was covered in fluid.

Hello. I would need to know what kind of vehicle this is to be able to help you with specifics. From what you are explaining though it sounds like a transmission failure. When there is a transmission problem the vehicle...

Q: Too Much ATF?

Hello. The shop you took the car too is absolutely correct. Your transmission is like your brain, if anything goes into it that may be foreign will fail. Your engine is like your body. You can add things to it...

Q: Clutch pedal goes to floor when pressed

With the symptoms you have described, the most likely cause is a leak in the clutch hydraulic system. If there is a leak on the system it causes air to enter. Since air is not able to be compressed the...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...