hms09

2002 LS430. My brake pedal has gradually become really soft and mushy. I had the master cylinder replaced about 1000 miles ago and the mechanic then said the pad ,rotors and calipers were good. The pedal never has been really hard, but gradually has gotten to this very soft and mushy state. Could this be a sign of air in the system? Any suggestions? What kind of pedal feel does others have?

Thanks,
Harry

bmore430

Air leak or pinhole in the lines or master is going bad already

Lynzoid

Nnnope bmore430, not likely.
This is the first time i heard about ls430 master getting replaced. No, really, that reliable.
This is known issue and was discussed here previously in depth.
Basically it's either sticky cylinder (most likely one of fronts - there's 8 cylinders in front in total) or (and) hoses deteriorating and contaminating the brake fluid (this leads to accumulation of gunk inside cylinders and that makes pedal awfully 'untrustworthy').
You need to get some repair kits (there's separate kits for cylinder seals and dust boots and kit with new springs, that hold the pads in the caliper) and carefully replace everything, plus replace all 4 hoses. Then bleed thoroughly and you'll get your 'good' brake pedal back.
I did.

bmore430

It seems like quite a coincidence this happened right after he said a new master cylinder was installed. Was it an oem lexus replacement or a rebuilt parts store unit?

hms09

I really don't know. The work was done by my usual Toyota dealer. I will find out. I don't think they would have used a rebuilt unit.

toddmorr

unlikely the toyota dealer have bled it improperly. i like lynzoid explanation

honasbone

I may be technically challenged here. I'm having trouble searching your posts, Lynzoid. I know I can look at all of your posts. But since there are hundreds of threads under your name, i'm not sure how to get to the specific thread that talks about caliper repair kits.

My issue is when I push the brakes, the pedal travels quite a bit and requires quite a bit of extra force to stop. A second pump alleviates most of this - the travel shortens up quite a bit and the force exerted to stop is decreased. I'm thinking these repair kits may help.

That all said, where do you purchase these repair kits? Can I get them from Sewell? Not seeing it on their site.

Sorry to sort of hijack the thread.

LS430Lexus

Also curious about the color of the fluid. If contaminated, my guess is the fluid would turn dark. In any case, if you go to the trouble of replacing hoses, try stainless steel. Not absolutely necessary but a nice upgrade. My fluid was contaminated. Flushed entire system and replaced hoses with Stop-Tech stainless steel. Brakes are firmer, pedal higher and less fade. Fluid has remained the color of cooking oil.

Combine that with replacing the cylinders as Lynzoid suggested and I believe your problem will be solved.

Sorry, my guess is that they used rebuilt master cylinder.