DIY LS400

I recently bled the brakes on my car hoping the feel would improve, but it hasn't. It is very soft and almost touches the floor. However they grab and stop the car very well.

I searched and I found that someone said that all the LS400s he drove had a soft brake pedal.
I was wondering if this is really the case for UCF LS400s.

Also while you guys are here, have any of you had problems with a PS hose leaking? I have a leak somewhere, but I haven't had time to go underneath to see where it's leaking from.

j stuff

iTrader: (5)

my PS hose was leaking as well, my mechanic got some generic hosing and cut it off to fit. Replaced my leaking hose and refilled PS fluid. All is well now

PureDrifter

iTrader: (10)

that wont work with the high pressure hose, it will need to go to a hose specialty shop and be rebuilt, or a new OEM part installed.

and the reason the fogs look yellow-er is because ur factory HIDs have been colorshifted, eventually your 4300k fogs SHOULD shift to a similar color, probably after the first 50-80hours of use.

and UCF21 does NOT imply the 98-00 model, UCF20 actually is the chassis code for ALL 95-00 LS400s, the UCF21 was a special model, which had air suspension and some other goodies

TJW98LS

iTrader: (1)

Mine are very firm compared to many cars ive driven... Jaguar, lincoln, benz...


Mine have incredible stopping power.

jcrome04

Mine are firm and grabby! I like the fogs, but I'm a personal fan of 2500k or 3000k, I'm a sucker for yellow fogs

DIY LS400

o thanks for the info! I don't know which hose it is yet. I'm going to check it out when the weather gets nicer.

I know that HIDs get more blue over time, I didn't realize it also happens to new ones have to be "broken in". Those low beams are still the factory bulbs.

What did the UCF21 have then, air suspension, navi, nakamichi[?] sound, fully loaded? My car has all the options, except the navi, nakamichi sound and air suspension.

anyway, I believe it was SKperformance who said, in another thread, that all the LS400s he has driven had soft brake pedals. What could be causing this the, broken master cylinder? Perhaps I bled them in the wrong pattern, I did it FL, FR, RL, RR. Does anyone have access to a Lexus FSM?

skperformance

iTrader: (6)

I did say all the ones i have driven are very soft pedals. If you make an emergency stop and jam the pedal it will sink to the floor but stop you fine. Right after that the pedal continues to get worse sinking more and more until you finally hit the floor. It drove fine to me until i let my wife drive it and she got scared and said you have no brakes since the pedal was almost to the floor. . I need to find out why the vac assist is not up to par.

DIY LS400

^ It could be the master cylinder, brake booster or there's still air trapped in the system.

I read on here that the 2nd gen GS's have a problem with the brake booster failing. Is it possible that LS's use the same one?

CK6Speed

iTrader: (1)

My 99 LS400 that had 55K miles on it had what I would consider a soft pedal feel compared to all my other cars which had rock solid firm brake pedals. My 93 SC400 was the exact same feel, and to some degree my 94 ES300, but not as soft as the LS and SC. Now, that said the brakes themseves grab really well. Probably the most grabby feeling brakes of any cars I've owned. They stop the car very well, but too me the pedal feel was kind of lacking.

Oh, my wifes old 2004 RX330 actually felt okay. Not rock solid firm, but not really soft either compared to my other Lexus cars.

skperformance

iTrader: (6)

I would say it was fine if it was linear on every stop . Like i mentioned above if i make an emergency stop every single small stop on that trip feels way to far for pedal travel. I am going to start by replacing the hose to the booster and running some throttle body cleaner through the hose to clear up the area of the manifold .

I have a feeling the booster itself has a small rip in the diaphragm and is causing the issue.

DIY LS400

Does anyone know if the LS and GS share brake boosters?

Blavatsky

I have noticed recently mine are pretty soft....topped off my brake fluid, waiting to see if I can tell a difference (it was a little low).

As stated before, if I need to stop quick the car defintely stops HARD...but if I'm just kind of applying the brakes to roll to a stop it feels like you have to push in a good bit before any stopping power is really applied.

DIY LS400

^ If it's low, it could mean you're brake pads are worn.

Yea that's exactly how my pedal feels, I have to push maybe almost an inch before you can feel the brakes grabbing slightly and the pedal goes to about an inch off the floor when I push it all the way I can.

Neofate

iTrader: (1)

There is alot of play in the LS line.. and I think many of the Lexus brake designs in general. IE: That is the intended function. Yours might be a little off, which with so much leeway from the factory it seems very odd when it is off even slightly.

Someone asked if the GS shares brakeboosters. I do not know if the parts are exact, but just like other car manufacturers alot of the accessory equipment is either identical, or VERY similar in design on other models by design. No need to redesign the brake booster radically for each variation of car model.

While on the subject of brakes. How low do pads generally have to get before the brake sensor flips a light on the instrument cluster?

qha_vn

when i first drove my 90 ls400, the brake pedel feel was as if i nearly lost it. pedal sunk deep to the floor and there was almost no feeling of stop point. the car stopped great however

the feeling is now the same after a year of driving. this is totally different from my previous 88 nissan bluebird which had a very firm pedal feeling

i read somewhere in this 4r that there is an after market metal brake line upgrade that provides better pedal feel. anyone tries it? whats your feeling?