Greetings.

Anybody know when the brake fluid and power steering fluid is supposed to be changed in a 3.5 V6 2007 Monte LS/LT?

I had the Maintenance 2 done at 30K, and the Maintenance 1 done within the last two months at 35K. During that 35K Maintenance 1 at a nearby Chevy dealer, the service advisor encouraged me to have the brake and pwr steering fluid flushed and changed. Is that about the right time/mileage to have it done, or was I being "upsold" something I didn't necessarily need for the dealer's greater profit? I ultimately chose not to have it done, but am wondering if I made a mistake. The car was not (nor is it currently) exhibiting any brake or steering problems.

-M

 

dude was tryin to score on ya man...

no need at all haha...

no need to really flush a power steering system, unless you contaminate the power steering fluid with something else...

same with the brake fluid...

 

Actually, brake fluid breaks down over time. It also absorbs moisture from the air. As a result, it can rust the metal components in a brake system, as well as wreak havoc on an ABS unit. I recommend every 2-3 years on the brake fluid, (depending on climate, drier areas can get you closer to the 3 year mark). Color is another indicator. If it's a clear to a light yellow color, it's still good. If it's brown to dark brown, it's time for it to be flushed. The power steering fluid shouldn't have to be changed unless the pump goes out or foreign matter gets in the fluid.

 

Brake fluid is hydroscopic, and will absorb water as it gets old. This can cause the brakes to start performing poorly, as the water will lower the boiling point of the brake fluid.
There's usually not a recommended mileage for changing the brake fluid, but it's generally a good idea as the car gets up there in years. Pretty easy to do, just potentially messy.

 

You're supposed to change fluids?!?!?1?!?

I've never before in my life heard of changing the power steering fluid, unless you had to change out the whole system and just redid it anyway. I think the biggest rip off I ever heard of was an "engine flush" which would be done during an oil change... no need for that at all in my opinion.

I've never changed the brake fluid in a car. Never really noticed the peddle fade or anything either though. How does moisture get into the brakes? It's a sealed system. Unless you're leaving your master cylinder open all of the time, then you shouldn't have a problem.

 

I've never heard of a recommended interval for flushing power steering and brake fluid, but I have heard it should be done from time to time. Commonly I've heard it's best to judge by fluid color.
On my cars, I never ran into a scenario where I felt the itch to do that (except the Impala we just got). Usually something happens (leaky brake line or something leaks with the power steering) before i see the fluid looking bad.

The Impala I did not do a true "flush". But the brake and steering fluid when I got it was black. So using a item that looks like a big turkey baster, sucked the fluid out of the resevoirs and put clean fluid in. Again, not a true flush or change, but I see it as a significant injection of clean fluid (better then 100% of the old stuff). Depending how things look in spring/summer, I may flush the entire system on the Impala.

 

Ideally it is sealed. It is not 100% air tight though. There is water in all air. Brake fluid is hygroscopic. According to the laws of diffusion, there will always be a consistent supply of water in contact with the brake fluid. Therefore, the brake fluid is always absorbing water.

Granted it's a very very slow process, which takes years to degrade the fluid.

No, you won't notice a difference in pedal feel over time. The mechanical parts in your braking system will wear much more quickly than the fluid will, causing a much more drastic effect on braking distance/feel.

Is it worth the $5 and 20min of work for peace of mind that the brake fluid is fresh on a 10yr old car? Yes.
That's a start to completely flushing the brakes. The other part would be to put a full bottle of fresh fluid upside down in the master cylinder, then bleed the brakes at the bleeder valve for each wheel until the fresh fluid was sucked in. Doesn't take all that much fluid to be honest.

 

I use the 'turkey baster' method to renew power steering fluid occasionally.

I am a proponent for periodically (every few years) flushing old brake fluid for the reasons already mentioned. If it looks dirty/dark, do it sooner.