Soft Brake Pedal

itarumaa

Hi,

how are you all,

just wondering, my Ls400 has a soft brake pedal when engine is running. When the car is in P, the pedal is soft (and goes to floor), when in D, then it is soft but when pressed it starts to raise from the floor, also revs drop slightly when running in d and the pedal is pressed. When stopped in traffic lights in D the pedal is much harder and does not go to floor so easily than in P.

Brakes work fine, there are no leaks and system has been rebleed 2 times.

It is only that pedal is bit too soft that it should be.

Thanks.

Mr Benevolent

The LS400 forums say that it's usually caused by a faulty master cylinder, but if it's only happening in P I dunno. Upgrading to steel braided brake lines tend to improve feel a lot. The 400 is well known for soft brake feel that doesn't affect stopping.

itarumaa

Yes I was thinking as well, if the pedal is supposed to be soft in the first place.

Mechanic told me that there is no air in the system anyway, so hard to say.

Also when I turn the car off, then the pedal goes hard just like it should be in "normal" cars.

itarumaa

Works now, I connected the bleeding bottle to Brake Actuator, opened the valve and pushed the pedal couple of times.

Then I put a rock in the brake pedal, and opened master cylinder valve.

This with engine running and now the brakes are fine.

thank you for advice.