boofus1

Recently a professional driving instructor told me it was a good idea to change out all the fluids on my '08 C6 with 21K miles. He said he just felt it was a good practice, that the existing fluids might have partially broken down/degraded. I always thought keeping them topped off was good enough. So at my local Chevy dealer a complete change out is $740!

What are people's views on the merits of complete fluid change outs versus just keeping them topped off?

MikeERWNC

7 years on the brake fluid? Many people have done much worse things.
I would be replacing the DOT3... But I am bias, I do all of my fluids very 50K. 1.5 years.

It is just for piece of mind and to keep my work car fully maintained.

simplegto

That price is crazy. I change mine but do it myself.

ufso

Bought my '05 in '04 and the only fluids I have changed out is the oil, once a year (12,000 miles or once a year, whichever comes first.) Car has only 38,000 miles...

EVRose

I would change coolant and brake fluid only due to their age, not mileage. If manual trans then clutch fluid too. Thats it.

spdkilz911

Had all of mine changed a couple months ago. Car only has 40K on it but it's an 08. The brakes are unbelievable after the fluid change.

Larry Myers

$740 for fluid change is a giant ripoff.

Best advice: follow the guidance contained in the owner's manual.

AORoads

I'd do them all: brakes, rear diff, man trans, clutch, PS, coolant on an almost 8 year old car. I'd also find an indie shop that doesn't charge as much for fluids and labor, but uses OE fluids, or at least Mobil1 fluids.

Rogers 07

I agree, it is a good practice to change the fluids after 5 or more years! Other than the cost at a dealer, changing the differential, trans and brake fluids fairly frequently particularly if you race it or drive it hard, is really cheap insurance for longer equipment life!!!

Dano523

Yes, good idea, and lot cheaper if you learn how to change the fluids yourself instead.


On mine the clutch fluid is always being changed out via the ranger method to keep it clean, the brakes fluids get changed out after heavy tracks sections since they may have been pushed close to the point of boiling (quick with a power bleeder), the motor oil changed yearly or better, and other fluids every few years instead.

Of these every few year fluids, the one that needs it the most is the diff, since the diff has locking clutch discs and the material from the discs as they wear does contaminate the fluid. If you have a manual trans and hard on it, then sync's can wear as well, and this contamination in the fluid is a good thing to get out with a fluid change as well.

v26278

The fluids protect the internals of all the mechanical components, one look and you can see that they do get contaminated. Also, the anti-corrosion chemicals in the coolant break down after 5 years. I would follow the owners's manual schedule at minimum, and increase the frequency if you're hard on the car. I change my oil every 4k miles (2x per year) as per the OLM, and my clutch fluid every year (owners manual specifies every two years) based on the heavy clutch use involved in daily city driving and my desire to pre-empt any problems with the clutch hydraulics, its cheap insurance.

FAUEE

Brake fluid is one that is a VERY good idea to change out. Brake fluid absorbs water, which dramatically decreases its effectiveness. There's a chart out there somewhere that shows the degradation of brake fluid with time, and the boiling point of it drops dramatically after even just a single year.

LS WON

I had the dealership change all of my fluids to Amsoil. It didn't cost that much even if you include the price of the Amsoil fluids.

1bdvet

I have 05, two years ago had all fluids replaced! Car now has 49,000, where good for couple more years.

C6ToGo

I agree. Learn how to do simple maintenance and you will achieve self-satisfaction and a sense of accomplishment.

Looked on my service history spreadsheet for my '07 A6. $129 for 5 fluid changes AND 2 filters:

Prestone DOT4 brake fluid swap
Prestone PS fluid swap
Prestone DEX-Cool anti-freeze swap
Mobil One and Delco oil filter
Trans filter with Valvoline Dexron VI Synthetic

Dealer swapped my diff fluid a while back under warranty.

C66 Racing

I am a big proponent of fluid change out as well. I think the real problem is that over time the factory fill fluids, particularly tranny and diff will shear down in viscosity. This occurs when the molecules that make up the fluid break, becoming smaller - thus lower viscosity. I had the factory fill tranny fluid on my 06 CTS-V tested at about 10k miles and it had already sheared low of out grade. Lower viscosity leads to lower fluid film strength which in turn can lead to increased wear. Aftermarket synthetics are less prone to this viscosity shear down.

donnie1956

I just purchased a 2006 and need to change all the fluids. Where can I find the info on how much and what grade/type of product for each area?

ruxvette

I agree...with the addition of rear diff change just to make sure it is the latest and greatest oil.

Gearhead Jim

Your Owner Manual should have the specs, except the differential fluid is now a much better product from GM. Dealer can tell you the name/number of the new fluid, a bit pricey but worth it. I think it's called "Dexron LS Gear Oil", or something similar.

Gearhead Jim

And I would stay with the offical GM fluids through the indie shop.