steverhode

I am going to get a 400h, but I'm hoping you can give me some more info from an owner's perspective.

When I think back on my test drive the other day of the 2008 400h the other day, the only negative that is staying in my mind is the vibration on brakes when coming to a stop around town. Now I know that some or all of this is normal due to the regenerative power, converting braking into battery energy.

What I want to know is:

1) Does it get any smoother when the car is no longer new?

2) And, more importantly, is this something that, based on your experience, will continue to bug you some after you buy the 400h or will you eventually stop thinking about it much?

I'm sorry. I meant to post this into the 400h forum. Perhaps if any of you visiting the 350 forum happen to be 400h owners, you can share your thoughts.

jednav

I'm not sure of the 400h, but the braking ability of my 350 is superb, no vibration whatsoever.

Test another 400h. Vibration is not normal at all.

Lil4X

Sounds like warped rotors. If the steering wheel rocks left and right under moderately hard braking at freeway speeds, your front rotors are warped, If you feel this vibration at lower speeds, try to drive another example and see if it is common to the model. I don't believe it is - although there were some issues with the programming of the regenerative brakes early on that might have something to do with this.

If you are considering buying this particular car, have their shop check the front rotors for lateral run-out. If they are out of spec, they should be REPLACED, not turned on a new car. There is a TSB on this issue. Most of the problems were solved early in the RX 330 run, but some grease-monkey with an impact tool may have overtorqued the lugnuts, warping the rotors. Not something you want to live with.

steverhode

I'm NOT buying this particular 400h. It's the wrong color. And, what I felt, happened on a slow speed stop at at about 20-0 or 10-0mph. It was like a studder, much like when anti-lock brakes kick on a hard stop. The salesman told in advance to expect something like that since it was the brakes converting braking energy into battery reserve.

MadloR

This type of "vibration, harmonic, jitter etc" can be caused by several factors...

One is rotors, either rusty (i.e. vehicle has not been driven for a very, very long time), or warped (brakes were not allowed to be bedded in, hence first shock of cold - heat - cold cycle caused the rotors to warp).

Tires, you may have a bad tire or if the tires have worn unevenly or developed a pattern. Probably not the case if a new car, but sometimes dealers pull fast ones, like swapping tires with the demo vehicle that the sales manager drove.

Suspension, highly unlikely on a new vehicle but you never know... if a suspension bushing is defective or something in the suspension is loose, under braking this "looseness or weakness if you will" can become more evident under load.

The RX 400h is not known for poor or uneven wearing brakes. The regenerative system does not by nature "add" any additional harmonics or instability while braking. I find the brakes on my 400h to be smooth, just like any well designed braking system.

Occasionally, the system will experience a hiccup if braking under load and incurring a bump or road imperfection, within a split second the regenerative system kicks off and for a split second (but, the seat of your pants feeling, seems more like a full second or two) it feels like the brakes have disengaged while the actually the hydraulics for the friction part of the braking system kicks in (the pads actually squeezing the rotors).

This particular condition I avoid almost all the time due to instinct, whenever braking with a conventional vehicle I have always let up on the brakes just before going over a bump or pothole, so as to let the suspension do its job while then immediately getting back on the brakes to slow the vehicle down. Doing so has served me well, while braking with the regenerative system deployed on our 400h.

Cheers,

MadloR

herbvdh

I have no vibration in my brakes at all. My thought is maybe the ABS kicked in for some reason that would give you vibration also.

SLegacy99

Are you feeling actual vibration or are you just not used to the braking of this car. Its very different, because of the regenerative brakes. As you press harder, the hydraulic brakes kick in making a bit of a jolt I found. I dont drive the 400h often, but I think Im getting the hang of smooth braking, but like I said this car is really unique.

If its any consolation, Car and Driver said that based on the wear and tear of their test 400h, they believe that the brake pads will never require replacing. So theres a few hundred dollars saved.

steverhode

I think that might have been it. I'm still getting a 400h. My color combo is supposed to be here by Dec 4th and perhaps sooner. I'm getting really excited about owning it.