syzygy

Hey guys, I was driving my father's LS 460 yesterday and noticed somewhat of a "surging" phenomenon upon braking.

Applying light but steady braking resulted in oscillating braking behavior. It seemed as though the braking would oscillate in intensity/efficacy from moderate to "extremely grabby."

For example, decelerating from 60 MPH might look something like this (length along one dimension is proportional to time) -

60...57...54...51...47.44.39...36...33...30...27.22.18...15... and so on

........................."brake surge".............."brake surge".....

Is this a cause for concern?

It has not caught the attention of my father - I suppose he's either gotten used to it or hasn't noticed, but I just wanted to be sure.

rominl

iTrader: (4)

doesn't sound normal for sure, brakes should be linear. it doesn't feel like vibration i suppose?

maybe bring it to dealer to check it out

frotiss

mines do the same they said its normal for that car

Johnny

Never happened to me on either the 460 or 600. The LS has big hefty discs which in my tenure did not fade or suffer any runout (warping) caused by overheating discs that are too thin to begin with - an all-too-common annoyance with most cars. Better bring it in to check for that or some play in the bearings (although rare, you never know). Another possibility would be tires (balance or uneven wear), or even caster & camber.

Nospinzone

What you are describing sounds like hard spots on the brake pads. This typically occurs when brakes are not properly broken in. With new brake pads the driver should stop the car with long gradual stops, as opposed to jamming on the brakes. Hard braking with new brake pads causes hard spots on the pads. This in turn causes the brakes to grab and release thus giving you that surge sensation.

The only thing you can do is get new pads and probably have the rotors turned just to be on the safe side. Then, tell your Dad to brake very gradually for the first 500 to 1000 miles. After that he can start braking hard again!

joedaddy1

iTrader: (1)

maybe you are feeling the transmission down shifting...
i know i feel it when i drive our LS and always think "8 is way too much..."

syzygy

Interesting. I appreciate the responses, all.

My dad does have a habit of braking hard at the last moment at stop lights, much to my mother's dismay. Nospinzone may have resolved the issue with his post. I will look into it.

On a slightly unrelated note, I must say it's truly a pleasure driving the LS 460 (I personally have an '09 IS350). Definitely garners plenty of looks from women on campus when they see a 21 year old driving an $80,000+ "executive-style" luxury sedan. Car has surprisingly powerful acceleration for being such a large sedan, as well. Very impressive.

Johnny

I garner lots of looks from some 60-year old sweeties. Perks up my Botox...

jlawr

I used to look for James Garner (teeheehee)

Mike_TX

What would you have done with him if you'd found him?

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eXstasy

Before doing this you can try to re-bed the pads to even out any uneven deposits you may already have on the rotors. If this does not work, then go for pad replacement and/or rotor resurfacing.

g26

It is a barely noticable surging (good description), slightly herky-jerky stopping action. It is VERY subtle and I do not think most people will notice it. However, I just started noticing this after the last service in which they rotated the tires and checked the brakes as part of the service (all green boxes checked on the itemized maintenance list).

I will be bringing the car in to get checked out as soon as I get a free afternoon. I get the feeling I will get a "this is normal" or "buy this, this and this" routine......

I see one other poster here who notices this braking behavior. Could this really be something normal?