Our 2004 Tahoe has 76,535 miles as we speak. Last brake fluid flush was 3 years ago at 59,260. First flush was 10/20/2008 at 29,338. Had a LOF today and advisor said 3 years is the GM recommended interval . OK, says I, will bring it in next week.

Went thru my owner's manual and lots of fluid change intervals are in there....but not brake fluid. Just curious (after 12 years).....why this is not in my schedule.

Thanks

 

I've had cars with 250,000 on them... no brake fluid changes...

Not saying that's a good thing, but they seemed to stop fine

 

yep, same here.
Why its not listed, who knows. Industry standard for changing is every 2 years. Will you notice a difference; nope....maybe if you were a competitive race car driver and the boiling point of the fluid mattered. It does look nice when the fluid is new.

 

I believe the performance loss comes from moisture that is adsorbed by the fluids over time. It's my understanding its moisture that turns the fluid its off color from new. Moisture in the system can cause rust and sludge as well as sponginess as it compresses differently than the brake fluid itself...
My "flush" process is to siphon out what is in the reservoirs i.e. brake, power steering, refill with fresh and be done, as an option you could re-siphon out after refilling it and running it for a day or so, this should give you a high percentage of "new fluid" in the system without having to open the systems up or drain it. Do I have a set period of time that I do it? no not really, my truck is now 9 yrs old and I have done it 1 time.

As for brakes, you really should have the system bled at each pad change, this will flush the system and remove any air that has entered the system over time.

my 2cents

 

The general consensus is more for time, than mileage, if at all.
Many things can cause debris or mositure in the lines, but, remember that what may be in there, is moved into the cylinders, before being discharged. So, when you do bleed, don't chinch on the volume of fresh fluid, ie: a copious flush.

 

yea, when changing pads it's not hard to loosen the bleeder and let some out... i bleed it out, dig it deeper just to throw it away, i bleed it out... lol

it's acidic, so don't get it on your paint!

 

Many of us use a length of clear Plastic Tubing, slipping it over the end of the Bleeder, and down into a Container. The old fluid then can be properly disposed of.

 

the discolouration imo is from the seals in the system. yes b fluid is hydroscopic...but I have seen open containers of brake fluid 1year old look clean and clear like the day they were opened.