Brake Fluid Change

curiousB · March 30, 2013

I'm guilty of not changing brake fluid in 40-50k miles. How much of a pain is it to do this? I bought fluid 2 years ago to do it with (still sealed closed). Should I throw away and buy new?

landar · March 30, 2013

Since the new fluid is still sealed and has not been exposed to air or contaminants, I would not hesitate to use it. Opened container would be another matter.

The procedure is not a real pain, IMO, but does take some time and care. Whatever you do, and you probably already know this, you do NOT want to let any air get into the master cylinder while bleeding each line. That would mean air into the ABS modulator and then you have to bleed that...not real easy.

You can go vacuum pump or just do the old fashioned way of pumping the brake pedal and opening/closing the bleed valve. That is the method I use but it does require a helper (and my 'helpers' usually do not have the patience that I do).

I always start with the wheel(s) furtherest away from the MC and work my way forward.

Here is a post on that other forum -> http://www.clublexus.com/forums/ls430/619055-brake-fluid-change.html

SRK · March 30, 2013

I don't know what kind of booster is used on the 430's, but if it is the combined master with traction and abs control, and uses a servo motor to build hydraulic assist pressure like in my 98GS, then the key has to be in the run position to get fluid to move. With the key on bleeding happens just like normal, off and it doesn't. Head Lexus tech told me that, and I think I read about it as well someplace else. It worked well for me and I found a couple of bubbles of air in the front callipers ( been there for years I think from the previous owner) and removing them sure improved the brake feel!