I am taking my 2002 FX4 in Saturday for new front pads & rotor turning. They are also trying to sell me on a brake fluid flush & refill. With only 42k miles, that seems a little early for that. Or is that normal for a brake job?

 

is the 42k your original brakes? If so, that's pretty good mileage, which says you're not too hard on your brakes. If it's second or third brake job, then you're pretty rough on em, and may do it because with all that hard braking, you're fluid may have "overheated" a few times which can break it down chemically. Hope this helps! Or that's how'd I'd make up my mind. FWIW, there's probably some 30 year old cars on the road with original fluid, and they can still stop on a dime.

 

Brake fluid is hydroscopic, meaning it absorbs water. The water can get through the seals and when you have had the cap open. The brake fluid heats when activated, and the water inside boils, which expands and is easily compressed. The braking force is reduced. That said, typically this is important to vehicles needing extreme braking force and vehicles which use extreme amounts of braking to get the system that hot, likely race cars or cars that are driven autocross. The normal driver probably will not notice the difference between existing fluid and new after flushing. New pads and surfaced rotors will make much more difference. you will notice now that most shops have the latest new and easy fluid flushing devices (i.e. brake flush, power steering flush, trans flush) all of a sudden, changing the fluids has become so much more important. Think back to all the vehicles you ever took into a shop, how many ever mentioned fluid flushes before this equipment became available? Shops needs to recover the cost of their machines, and it's easy money since the machine arrived.

 

Very well put, Big Red.

 

I flush mine every 30K.

As Big Red sez, brake fluid is hygroscopic (hey, someone corrected me on that earlier this week), meaning it absorbs water very easily. Brake fluid contaminated with water has a much lower boiling point than fresh brake fluid, which can affect performance and brake pedal feel. Yes, it matters a whole bunch on a race car, but I want all the braking power I can get on the street too.

I'm **** retentive about everything mechanical on my truck, so I flush my brake fluid every 30K. Especially since living in Georgia, I haven't found a cool, dry place with low humidity anywhere in the state.

 

I flush my brake fluid every two years on my vehicles as general maintenance.

 

If the brake fluid is no longer "clear" and is very dark brown in color, then I would have it flushed....

I do mine about every two years. By that time, it's brown and the new stuff is clear.

It's pretty easy to do in a garage, but it can get kinda messy.... I do my own and it's not so bad now that I know what to expect!

Good luck!

Mitch