TriniLex

I have noticed that my brake pedal goes to a normal halfway point at a traffic light. If I apply some more pressure the pedal will go slowly down to the ground.
I have no leaks on the ground. The reservoir is above the minimum line
There is a audible squeak when I release the brake pedal.

The brake booster was replaced on the recall a while back.
Could this be the brake booster again?

or is it the master brake cylinder?

thanks

RXGS

iTrader: (2)

I would check to see if any of the calipers are sticking. At some point every car I have owned has had a lousy brake pedal feel and it was either slider pins that were gummed up or calipers that were completely seized.

TriniLex

I will look into the caliper issue.
It does have a audible squeak when I brake while backing out of a parking lot (no squeak from caliper going forward though ?)

But would this cause the pedal to go to the floor. Seems to be doing it more now when I press really hard.
Also there is a louder squeak at the foot pedal area when the pedal is released.

There was a recall on the break booster

IN 2010 it has the recall described as: A0M/ALG REPLACE MASTER CYL CUP-HIGHLNDR/AVALON/IS/RX ~ ~ALG-SAFETY RECALL ALG - CERTAIN 2006 MODEL YEAR LEXUS IS AND GS VEHICLES & CERTAIN 2004 THROUGH 2006 MODEL YEAR RX VEHICLES BRAKE MASTER CYLINDER CUP REPLACEMENT ~ ~SSC 9LG ~ ~A0M/ALG REPLACE MASTER CYL CUP-HIGHLNDR/AVALON/IS/RX

Can that be the culprit again?

anyone experienced in how lexus warranty on recalls?

thanks

thomas1

That doesn't sound normal at all, sounds like the booster is damaged or you have a vacuum issue.

DennisMik

The master cylinder could be leaking internally - bad o-rings.

A bad vacuum booster or bad vacuum lines usually cause hard to press pedal, not pedal going to the floor.

TriniLex

Just drove it home
Perfect no problems
I dont get it

TriniLex

The master cylinder looks like a straight forward job.
The vacuum booster is the black circle thing that the master cylinder is attached too?

On the recall they said they replaced the "cup" of the master cylinder. Where is that located?

5W40

http://www-odi.nhtsa.dot.gov/acms/cs...0V499-4567.pdf

LBZmax

Hello did you ever figure out this issue i am starting to have same issues for several months now and and seems to get worse.