alufront

Im a true admirer of Lexus accomplishement throught the years.
I own 3 lexuses. But two of it has brake problem. One is a lS400 2000,which i have posted the problem already. Another is the LX470 1999. 6 months ago, I felt the brake pedal to be extremely low, so I change the following:

1- 4 new cross-drilled rotors
2- all new brake pads and shims
3- drained and replaced the brake fluid

afterwards, the brake pedal was excellent, but after a month, the whole thing went back to low-pedal status again. For High speed or emergency brake , i must Pump!! of press the brake pedal more than once so it will reach its normal height. Therefore, went back to the lexus dealer ,and proceeded with the following

1- replaced the whole brake system, the whole master cylinder plus its accesories. (1400 dollars)
2- bleed teh system electronically with the lexus scan tool.

I though the problem was solve , but to my surprise, the brake worked well at the begining, and last week after 3 months, it was back to its low pedal status.

so went back to bleed the system again, but it will only work well for a few days and the low pedal cancer will come back.

what is the problems?????? Lexus engineer does not have a clue about it.

V8_Fan

Are you certain the dealer changed the entire master cylinder/electronic booster unit or did they just change the booster unit? (Toyota price of the booster is like $1200, master+booster $1500, then add on 2+ hours of labor; lexus dealer will charge more). From the symptoms, I would guess the seals within the master cylinder itself is going bad. The pedal going to the floor happens when any master cylinder is going bad. The Toyota master unit uses an electronic booster rather than the traditional vacuum booster. When you turn the key to "on" but no the engine on, you should hear the electronic booster pump. At any rate, the part and labor, if done at a toyota/lexus dealer, are under warranty for something like 1 year (that is, if the part is OEM and you buy from that dealer and have the same dealer install it).

alufront

Thanks Jim:
it is whole mastercilinder +electronic part. I got a good deal since I buy wholesale.

My brake is low but not literally low as to touch the floor, the brake does all the process as you described. The lexus dealer has no clue why does the pedals below normal levels. I have complained but no satisfiying answer and solution yet.

I just have to keep bleeding the brake system electronically each time the brakes goes low.

I have all repair manual,and have done all the steps to check the low brake pedal that it instructs, but no luck yet.

I really like this Suv, 60,000 miles, with 2007 upgrade , grille, wheels, lamps(rear and front) , 4300 philips HID , cross drilled rotors, can you provide more suggestions

Greatly appreciated
ALufront

Neil64

Did you ever resolve the issue?