Have any of you replaced your brake fluid? Do you think it is necessary?. I decided to do my own 30K service except for the coolant and brake fluid change. When I brought my RX into Lexus and told them to do both they suggested that a brake fluid change was not really necessary as long as the fluid looked clear, and it did.

I was of the understanding that the brake fluid is to be changed because brake fluid absorbs moisture. But I can't imagine a sealed hydraulic system, that has never been open to atmosphere, is able to absorb moisture.

What do you think?

 

IMO...Skip it.

 

In spades.

 

IMO replacement of coolant and brake fluid every 2 years (30K miles) is reasonable for an aggressive preventative maintenance schedule. I think it all depends on how aggressively you want to do preventative maintenance.

My experience with a previous car, a Mercedes Benz, is that MB recommended brake fluid replacement every year. I don't remember what the MB coolant replacement schedule was, but I think it was less than every 2 years, even way back before the improved coolant that is available these days. It would be interesting to learn what other luxury brands are recommending, since they basically use the same brake fluid and coolant and the designs are probably equivalent in this respect.

I don't think the brake system is really a "sealed hydraulic system". If it was, you'd have a point there. I think there's an air vent to the brake fluid reservoir, to allow for the fluid level to rise and fall with the movement of the brake pads.

One thing I would never do is bleed the brakes by pumping the brake pedal. I learned from personal experience on my MB that vacuum bleeding is the only proper way to do it.

 

Good question. I live in Mexico City with my RX300. High altitude and very dusty climate. Before I came here the fluid was quite clear, but after several months a little foul in color. I also noticed the brake felt differently. I change to a Bendix DOT 4. A couple of my Lexus and Toyota owner friends down here have the done the same, and it the brake feels much better. If they had synthetic brake fluid down here, I would have used that. I also switched to Hawk brake pads for my front OEM pads. The OEMs wore out very quickly with all the hills and crazy drivers.

 

Clear where? IN the reservoir?

I would bleed at least a "full pedal action" at the far rear wheel and look at the fluid that comes out from it.


Salim

 

Good idea... before doing that I would suck out the old fluid from the resorvoir (with one of those squize bottles) and put in new fluid. that way new fliud will run through the lines

 

I will not wait for the liquid to turn reddish. Reddish color will indicate that rust has started in the master cylinder and caliper areas. Moisture enters via the tiny air hole on top of the fluid fill cap.

Every two years is a reasonable changeover period.

What I've done in my other cars is to use a big syringe with rubber vacuum hose inserted at the tip and then suction all the old fluid from the master cylinder. Then, start the brake bleeding procedure starting from the wheel farthest to the master cylinder. There's nothing like the old style bleeding prodedure (two-man operation). I've tried new tools that claim to do a one-man operation but I have not been happy with any of them.

 

today at the firestone store the manager gave me a couple of test strips that test the fluid for "alpha components" and turn the test strip a different color. the darker the color, the more bad stuff in the fluid, which leads to corrosion - supposedly. my sc and my wifes ls both showed to be fairly bad.

does anyone have an opinion of this technique?

Frank

 

Lexus dealer service centers typically try to sell you more service than is called for in the owner's manual. More service = more $$$ for them.
If a dealer told me that a manufacturer recommended service isn't really needed at this time, I'd probably take their advice. I don't think this would ever happen at my local dealer though.

 

I believe BMW stated that brake fluid should be changed every 2 years and I strongly agreed. Brake fluid absorbs moisture which causes corrosion with time. Every 2 years, I hook up my "homemade" electric vacuum pumps to the bleed screws, turn on the pump, crack the screws open, and top off the fluid reservior until clear fluid flows out of the bleed screws.
Couldn't be any easier! Rotate the tires while I was at it.

 

I've heard every two years is good enoug, depending on the type of driving you do. And remember, once it's done...it's done. Why put off till tomorrow, that which you can do today?

 

"homemade" electric vacuum pump????

HOw?

 

I change my brake fluid 30,000 when I change my coolant w/distilled water.

I open brake bleeders and attach a small clear vinyl tubing to the nipple and run down into a pint jar. 4 tubes and 4 jars total. I open the bleeders and let brake fluid run by gravity into the pint jars while refilling the master cylinder with fresh fluid. Keep filling until approx a pint of fluid comes into the pint jar from each wheel.. Now, this does take a long time but it does work!!!

 

I would think replacing brake fluid via gravity pulls would allow air to enter the system at the bleeder screws. Did you pumped bleed the system to remove any air that had entered?

"Homemade" pump?

From the compressor in an old frig that I junked. Input side is the vacuum side, output side is the compression side. Of course you must attach (weld) proper connectors to the ends so you can attach the the vacuum to whatever unit you want. I use the same vacuum unit to service all my AC needs.