bwb911

I just purchased my 16 year old son a 1999 Lexus ES300.

We decided to replace the rear brake pads. A fairly easy and straight forward job.

After the replacement, we bleed the brake lines. Without the car running, the brake pedal is hard as a rock. But with it running, the pedal feels like mush and goes to the floor.

So I do my research and discover that we need to bleed the front brakes with the ignition in the on position so that the ABS motor will start working. We try that but the pump does not start pumping and nothing happens. I pull some of the ABS relays (just to see what will happen) and the ABS light will come. Otherwise, the ABS light is off.

So, finally, my question(s)...does this sound like an issue with ABS or am I doing something wrong?

tomf

Normally after replacing break pads, the engine must be started and the brake pedal pumped several times until the mushiness goes away. Did you do that?

bwb911

Thanks for responding.

Yes, I pumped the brakes several times with the engine on.

Since the bleeding, I have driven the car about 100 miles. The brakes still feel like mush.

I was able to do several panic stops (in an empty parking lot) and the ABS did engage. But due to the mushiness, even getting the ABS to engage was difficult.

LeX2K

There is no special bleeding procedure for your car bleed the brakes as per normal RR RL FR FL wheel. Best practice is use two people, bleeder open pedal pressed to the floor, bleeder closed, pedal released. Do this 15-20 times on each wheel. Do not bleed the brakes with the engine running the pedal will be way too easy to press and can drop quickly causing small bubbles.

Did you at any point let the master cylinder run dry?

bwb911

Thank you for your response.

Lots of good points on the bleeding process. I did not let the level drop in the master cylinder, so I don't think any air entered.

I'm going to re-bleed the system but this time use a some vacuum pump to pull the fluid.

I'll let you know if that makes a difference.

LeX2K

Unless you 100% seal the bleeder nipple to the caliper, using a vacuum pump can create more problems than it solves.

goose300

Sorry to dig up a somewhat old thread, but I am just curious if you ever solved this issue? I have been having the same exact issue on my car since I've purchased it last fall.

I've replaced the master, and bled numerous times and still did not solve the issue. I've tried bleeding with the car off, bleeding with the ignition on (but car off) and even tried the vacuum pump method which did not really work at all. I've had the case where I've bled it, it returns to a almost perfect pedal feeling, then goes mushy over the next few days/

Have you figured out any solution to this?

bwb911

I never did figure this out.

We must have bleed the system 4 times; all different ways. The pedal would always end of sinking to the floor, when the car was on.

Sadly, the car was totaled two weeks ago.

goose300

That's very unfortunate, sorry to hear that. Hope everyone involved is ok.