2007, 150k miles. When pressing the brake pedal to start my car, I get a distinct sensation of back pressure as the engine cranks. Just started this a few days ago. The engine starts normally and the back pressure stops when the engine starts. I do not have any other braking issues or noises while driving and no brake malfunction lights on dash. Could this be a forewarning of any kind that anyone has experienced?

 

I have noticed this occasionally in other vehicles I have owned (Sienna, Legacy) but never thought much of it. I have not had any problems that could be connected to this. I would guess your car is fine.

 

When mine had that problem. My battery was dying. Maybe go out and get your battery checked? It could be on the verge of dying

 

well well well...
I had the same problem starting on Friday night, when you start the car, the brake pedal seems to pump back at you... weird...
Saturday rolls around, and what do you know... my LS isn't starting properly, like a low battery type of start. Tried charging it up Sunday, battery charger light turns green, and thought, YES! dont have to buy a new battery.. but dang it! it didn't work, it won't hold the charge. Today, I just bought a new battery and installed it. Brake recoil is gone and my car starts up strong again.

 

Wow, my battery was "sluggish" today and I thought there was a problem with it. Now I'm convinced I better change my battery tomorrow for sure. Thanks for the comments.

 

I wonder if the pedal does that upon startup - when the battery is low - because the actuator can't maintain pressure when the car is off due to the low battery? Then when you start it the electric motor in the actuator kicks in, raises pressure and the pedal goes up. I often hear a distinct electric motor sound that lasts maybe two seconds sometimes when the car is off and parked....it may do this a few times after I shut it off. I read somewhere that pressure will bleed off after the car shuts down (slight internal leak?) and pressure needs to be built back up.

Sounds like an unusual design of the brake system/master cylinder.

 

unusual alright! we get this stupid actuator click...

 

Mine was doing if a week before my 100k service. I told my service advisor about how I had to jumpstart my car a couple time the week prior. he says that it was part of the service and that it would be check. $577 later, I get the car back and it has trouble starting that night. I almost didn't want to bring it back to them thinking that it could be from a problem he said I should get fixed. Before they finished my 100k, I was advised that my belt tensioner was starting to show signs of wear and that it should be replaced and also the control arm bushings were bad. I figure I could have an independent do my bushings and also the tensioner. I had a coworker check voltage on my battery and it was low ( I think 10.5 or so) so I just brought it back to Lexus and they ended up having to recharge the battery to test it because it was too drained to check. Advisor came back to me and told me its been 3 1/2 years since the battery was replaced and that is usual length for a battery. $120 later I have a new battery and hopefully the issues don't come back.

 

There was probably a miscommunication between the service advisor and the tech...like he never told the tech...or he did tell the tech and he forgot...or it was written down on the service order, but the tech forgot to do it.

I don't even know what goes into a 100,000 mile service, if I could take a guess it would be the usual laundry list of inspections...brakes, undercarriage, fluids, battery and charging system (lol), and just about everything else in the car, rotation...then an oil change and spark plug change. That about right? I wonder if they change the coolant? Probably not included in that price.

I'd also probably add that dealers sometimes have their own set service schedule that mirrors the manufacturer, but with other things added or taken out depending on the vehicle's history.