gripau1

Is there an official way from Lexus on how to do a brake fluid flush? I was told that I was doing it wrong??

I firstly remove the old brake fluid from the reservoir and replace with fresh fluid.

From there I bleed each the brake line via bleed nipple (starting from the furtherest line from the reservoir) by pumping the brakes until fresh fluid comes out.

I was told to put the ignition to the ON position (but not start the car up) and pump the brake pedals 40-50 times before bleeding the fluid. I've never done this step on a SC430 but on the Soarer this is what I needed to do because it uses a Nitrogen accumulator as a brake booster.

kjcole

I will be interested in the proper procedure as well. I've always flushed the brake system the way you described, that is, without the key on and the excessive pumping. Curious.

Kelly

tuterz

iTrader: (11)

anyone? .. im doing this soon..

kjcole

This might be close since the LS is a rear driver like our SC

http://www.lexls.com/tutorials/brake/bleeding.html

gripau1

I decided to bleed the brakes this morning as it was due anyway.
Out of my own curiosity, I did the usual, suck out as much of the oil brake fluid from the reservoir and put new Toyota DOT 3 brake fluid.

This time I left the ignition in the ON position (engine off) and undid the bleed nipple (rear wheel) and what do you know as soon as press on the brake pedal the nitrogen accumulator was activated and out shoot old brake fluid.

This beats constantly pumping the brakes up and down until new fluid comes out.

It seems the nitrogen accumulator assist the pumping of the rear brakes. Unfortunately the front brakes needs to be bleed the traditional way.

I hope this helps people.

thombiz

I flushed and replaced the brake fluid on our GS300 and SC430 a couple months back and there is a specific way in which flushing should be done. I don't exactly remember each step so I will continue to search for it, but part of the process is found on post #8 here: https://www.clublexus.com/forums/sc-...003-sc430.html

The LS Brake Flush Procedure above is NOT the correct way to do it, due to the existence of a fluid "pump" on later model Lexuses. From what I remember, it is important to follow the correct procedure or risk damage to the fluid pump. I'll get back when I find the correct procedure.

Ok, I found part of it, see: https://www.clublexus.com/forums/sus...luid-help.html See Post #3.

Press the brake pedal 40 times to obtain the proper brake fluid level in the res bottle.
Bleed the fronts first in the conventional way. (Yes the fronts first.) Top up the res as you go and don't let the level fall below the min line. ie open bleeding nipple, press, hold, release, close the bleeding nipple. Same as any car.
Then, when you do the rear calipers, turn the key to on, get someone to press the brake pedal and let the brake motor push the fluid out for you. Only let the brake motor run for 10 seconds or so at a time. Keep an eye on the res as the fluid will come out fast. Don't turn the engine on when you do this, just the key to the on position.


I'm going to add some additional thoughts.
First, take a turkey baster bulb or similar available from auto parts store and remove as much of the old fluid as possible from the brake resevoir, then fill with new brake fluid. The "baster" I got from Autozone dribbled and leaked, so I can't recommend them as a souce. As for brake fluid, I watched a Youtube bleed procedure and they recommended Valvoline Dot 3 Synthetic brake fluid. You'll probably need about a quart of it. Then follow the procedure above. Always top off the fluid resevoir after each wheel. When you do the rears, the fluid pump will come on and it will move a lot of fluid in a hurry, so monitor your collection bottle. When you have about 1/2 to 3/4 of a cup of fluid, stop and refill the resevoir.