larryp

This is a tough problem to describe, but I'll give it the same shot on this forum just as I've done at every 4000-mile service at the local dealership. Hopefully someone can give me some insight into fixing this troublesome problem.

When depressing the brake pedal, my RX has what feels like a 2 or 3 mm gap from the time I depress the pedal until the brakes actually engage. An example would be sitting on a 'slight incline", I can softly depress the brakes and the RX will continue to roll, once I push a little harder it abruptly catches the brakes. A second example is in stop and go traffic, if the car is rolling at 2-5 mph and I try and feather the break it won't engage until I pass the 2-3mm gap and it makes for a very jerky/hard stop.

I've had newer RX loaners and have compared the braking to my three other cars and all of their braking seems much more responsive. In that, from the moment you rest your foot on the brake pedal, the response is firm and consistent from a light feather to heavy braking.

I'm aware of the TSB's out there for the brake rotors (been replaced twice under TSB) and the brake booster (complete loss of brake pressure - pedal w/out pressure going to the floor)... and I've expressed these service bulletins to my service advisor. He continues to claim the service tech feels the brakes are within specification. Last visit after two years of complaining my service advisor said he would bring up the issue with the regional Lexus service advisor - three weeks later no answer.

To me it feels like a bad master cylinder...has anyone else experienced this issue? Any thoughts?

jim256

do you actually mean 2-3 mm? 0.1 inch or less? Every car I have had has more play in the initial brake application than that.

larryp

Hi Jim...

There is more play than 2-3mm...It's just hard for me to tell. What I'm trying to express that there is a gap between depressing the brake and getting brake response. It's not like pushing the pedal halfway before it engages. It's more like when you feather the brakesthere is no response and looseness until you push very hard causing an abrupt braking response.

xfirechief

How many miles on the brake fluid? I just had mine flushed at 50K with new synthetic fluid & the brakes are much better. Besides getting rid of the old fluid I suspect that if there was any air in the lines it was flushed out too.

tfischer

If there is some air in the brake lines, you will get a kind of soft feel to the brake pedal, because you are compressing the air first, before you are forcing the fluid through the system. It sounds like this could be a possibility. As far as I know, and I am no expert in this area, the only way to tell is to flush the brake lines and put in new fluid.

Depending on the miles on you car and/or its age, this might be a good thing to do anyway.

larryp

Good question Chief... I've spent the premium taking the RX to the dealership for all of its service. I just had my 40,000-mile service completed - I don't recall seeing on any past service invoice a brake flush.

I've had this problem since I purchased the car so I'm not optimistic a brake flush will resolve the problem. I have brought up this issue with the dealership every time I go in for service. I told the dealership on my last visit it's a shame when you purchase a $40,000+ vehicle you want a great driving experience every time you get in the car. Unfortunately, that hasn't been the case with my RX330 to date.

cantsleepnk

I know exactly what you're talking about larry cause my RX has the same problem.I always feel that my pedal is too soft upon the first application however it gets better after pumping the pedal once or twice.It makes driving (braking) smoothly in stop and go traffic very difficult. I know it's not right because me and my wife always feel a noticable difference between our car and every loaner RX we've had.
I tried to have my dealer address this but to no availe.They changed the front rotors and pads twice per TSBs but the problem always returns after a few hundred miles.A fluid flush did not help much either.I mentioned changing the brake booster per TSB but they said my car is not included.
Let me know if you find a solution for this.The brakes and the transmission are the only complaints I have about my RX.

salimshah

The only specification I know of is distance underneath the pedal to the floor, the first time you pump down on the brake pedal [rule of thumb your left toe should be able to get under the brake pedal when it is fully depressed]. You can think of this as the max throw ditance of the brake pedal. There is no spec for minimum travel to engage. In reality this distance depends upon previous application of brake and normal [don't confuse this with bad] wobble of the disc which pushes the pistons back. This wobble may be tad too much in your case. This wobble is due to how true your discs are as well as the play in the bearings. The other lesser suspect is the auxiallary brake [there may be too much travel].

There may not be anything wrong [out of spec] with your brakes. It could be a matter of getting used to your brakes.

Salim

larryp

Hi Cantsleepnk:

Thanks for validating the problem…after being told by the dealership many times there isn’t an issue its nice to hear I’m not crazy. I will certainly keep you abreast if I can come up with some type of resolution. After 40,000 miles I’m finally on a mission to resolve all of my “major” RX issues. It seems like every problem that has been recognized by Lexus/Toyota (and some that have not), I’ve had with my RX330. Prior to listing them I just want to state my car is garage kept and not driven hard. Note: This is the first vehicle I’ve ever owed that I had to search out TSB’s!

Front Rotors replaced twice – Repaired by TSB
Wind Noise – Repaired by TSB (not fixed taking back next service)
Transmission whine at low RPM – Waiting on A/C part per TSB
Radio Error 400 – Can’t play CD’s – Waiting on new Radio - warranty
Front left mirror; broken motor – repaired warranty
Brake Pedal Lag – service advisor said he would talk with Regional Lexus service – No
response going on 4 weeks.

Transmission Lag (talked about a lot on this forum) – Just found TSB TC005-03. Engine Control Module (ECM) Calibration – Shift Feeling Enhancement. Will present it next service.

I promise I’m not one of those “hypochondriac” car owners. I own four other cars 2002 BMW, 2004 Jetta, 1999 Expedition and a 1994 Camry – I have had less headaches combined with my other vehicles compared to the ’04 RX. Like you CS, if I could resolve the brakes and transmission problems I would be happy with my RX. I’m on my last straw though.

larryp

Hi Salim:

Thanks for the feedback... I've had my front discs replaced twice per TSB and the problem has remained constant. I do understand what your saying about the measurable travel, but what is difficult to convey is that there is a considerable "pedal lag" compared to other RX's I've had as loaners (and as you can see from my earlier post - I've had a bunch!

cantsleepnk

I 've had all of these issues except for the mirror motor. I'll never buy a first year model vehicle again even if it's from Lexus. At least Lexus aknowleged most of these issues and fixed them.

tfischer

Larry:

. . . but aren't you glad you didn't buy that Land Rover?

larryp

Tfischer,

Touché' ..... that's why I bought a Lexus!! :-)

Funny Note: My Lexus service advisor is a pretty nice guy (I know he has to walk the company line), He said to me spontaneously on my last visit, "You're not going to buy another Lexus are you?" - My reply, "I will but it's going to be a car."

tfischer

It's pretty hard to go wrong buying a Lexus car. I had the coupe (SC400) for about 10 years, and now have an SC430 convertible, now in year 6. Neither has ever given me any trouble. In fact, my brother has my old SC400 and it is still operating trouble free.

The '04 RX330 is my 3rd Lexus, and I thought I would like it more than my previous SUV (I need something that's a bit more practical than the SC), but I love it and think it must be the best SUV on the market. I feel sorry for people who have to have, or think they have to have, larger SUVs than this. It's only 8 inches longer than the SC (and 11 inches shorter than an Accord) yet it seems gigantic to me, and seats 4 adults in style and comfort, accomodates large boxes when necessary, and it goes through the snow, and that's all I need in my larger vehicle.

Clearly, no one model is suitable for everyone, and not every car is perfectly assembled, but these Lexus folks sure have the car building thing down pretty well.

larryp

It only took 44K for me to finally enjoy driving my '04 RX 330!!!

Front Rotors replaced twice – Repaired by TSB
Wind Noise – Repaired by TSB (2nd time but now fixed)
Transmission whine at low RPM – Repaired by TSB
Radio Error 400 – Repaired by TSB
Front left mirror; broken motor – repaired warranty
Brake Pedal Lag – I wasn't crazy, they finally replaced the master cylinder and fixed my problem!!!!!!! The braking is tight and responsive.

Transmission Lag (talked about a lot on this forum) – Just found TSB TC005-03. Engine Control Module (ECM) Calibration – Shift Feeling Enhancement. Will present it next service. - Fixed made a huge huge difference - smooth shifting as one would expect from a Lexus!!!

I feel like I'm in a new car!!!!!