PureDrifter

iTrader: (10)

you need to bleed the brakes.

1st gens dont have as much an issue with brake firmness as the 2nd gens.

skperformance

iTrader: (6)

well i loosened the nut for the plunger and moved it out some so it engages the booster quicker behind the pedal. Then sprayed some tb cleaner in the vac hose , I'll see how it goes tomorrow .

DIY LS400

^ was it hard to reach back there?

For a soft brake pedal, isn't it the master cylinder that's usually the problem? I only mentioned the booster because I read on here that 2nd gen GSs have a problem with them breaking.

skperformance

iTrader: (6)

Easy enough to reach , just take a 14mm wrench and loosen the locking nut then turn the plunger a cycle or 2 and tighten up the bolt again.
You do not want to do it too much as it is just engaging the booster with less travel. The proper way to do it is to get the plunger to engage faster with less travel and then move the brake pedal stopper the same amount so the pedal is also moving closer to you . So you will have more travel but same effect before it gets bottomed out. turning the plunger too much is going to cause the break to be activated all the time so they overheat as it is almost like lightly riding the break pedal.

I have driven all day hoping would not be causing the brakes to be engaged quicker and so far it is better , not perfect .
I still wish to find stainless brake lines , i have a set from an IS i am going to test fit to see if the fittings match , then all of us are in business, then to bleed those 4 pots which is a pain to do properly.

DIY LS400

wait by plunger you're talking about the actual rod that comes in from the booster, right?

Why is it a pain to bleed the 4 pots correctly? Is it because it doesn't have a bleeder for the outer set of pistons like most aftermarket kits do?

skperformance

iTrader: (6)

yes and yes

DIY LS400

How many turns did you turn the rod and the brake pedal stopper? I might want to try this out.

bankr

My 99 LS had a low brake pedal feeling. I mentioned it to the Tech when my car was in for some other problem. When I picked it up he said he had adjusted the master cylinder, I don't know what this amounts to, but it feels normal now. He acted like it was no big deal, there was no mention of it on the shop ticket.

Banker

bankr

Oops, sorry. Should have signed "Bankr"

DIY LS400

Interesting... maybe it's the same thing skperformance did?

skperformance

iTrader: (6)

after a week it is getting by the day , pedal has become firm in application without sinking to the floor anymore. For some reason it must be cleaning the plunger or activator inside the booster. Also i did throw some throttle body cleaner but doubt it would slowly make it better over instantly.

PureDrifter

iTrader: (10)

wanna take a pic of exactly what to adjust (or is this in the manual, i havent seen my car in over a week )

Blavatsky

+1, I'd like more info on how this is done before I start pricing a new master cylinder
Pedal is definitely not grabbing like it should, now that i've noticed it, gets very annoying.

skperformance

iTrader: (6)

Like i mentioned before it is the plunger . The plunger is connecting the arm of the brake pedal to the actuator of the booster on the other side of the firewall in the engine bay.
It is just a threaded rod that can be turned by hand once you loosen the locking nut.As soon as you take a flashlight under the dash you will see the arm and rod and it will make perfect sense. You are turning it to activate the pedal for faster engagement.

If any of this sounds complicated have a tech do it otherwise you will overheat your brakes from too much rotation.

DIY LS400

^ Which way did you turn the rod, clockwise or counter? Did you get it right on the first try or did you do trial and error?
Also how can you tell if you over did it and the brakes are slightly dragging, common sense?