Lexus RX-450H breaks stuck, won't drive away.

[Chris-LEXUS]

Hi, I struggled to find any relevant information on this issue or clearly related to the issue I experienced so hopefully this may help someone in need. Sorry for the self answering post.

Issue/situation:

• Gearbox moves into drive, parking break releases but car doesn't pull away. Feels like the car is rocking, rear breaks seem to be stuck.
• Car was taken to a car wash the day before and parked on a step hill. Parking break engaged strongly.

Solution:

• Throttle down hard unstuck each of the back wheels in turn. Careful as obviously the car will jump forward. There was a loud, almost cracking noise as the breaks released.
• No damage to the break discs evident, function as before.

 

Has anyone experienced this before? I was tempted to spray the discs with WD40 but that seems quite mad. 

[cruisermark]

I would get the parking break mechanism looked at?

Do you use the parking break often?

Is there a chance it was seized due to lack of use?

[Chris-LEXUS]

Thank you for the reply 🙂

^{"I would get the parking break mechanism looked at?"}

My service is due soon, I'll get them to check everything.

_{"Do you use the parking break often?"}

All the time.

^{"Is there a chance it was seized due to lack of use?"}

It had been used extensively before hand, 1000km and almost every day for 2 weeks. I just find it strange the only time this happened, I had washed the car before. Maybe the wet / hard breaking caused the seizing? 

[jumbojake]

all brake discs corrode as soon as you park the car ... the car wash might have used some chemicals to increase the effect, but also powerful jets get into places water normally doesn't.   It's not clear if your problem is the pads or the handbrake shoes.. possibly the handbrake  as that was used.  The rear pads are not used very often (only by the computer if hard braking)

note sure WD40 is a wise idea... I know it is water repellent (not lubricant), but it is an oil regardless and I wouldn't want to contaminate the pads.

maybe layoff the handbrake after a carwash (we don't use it much) .. and get it serviced next time to ensure mechanism is greased up (servicing rear brakes on a hybrid are a real pain .. Lexus wanted to charge a fortune to look at ours) 

[steve2006]

Chances are water has entered the drums during the car wash, the parking brake was applied, the water dried out and the drum gained a layer of rust which bound the brake shoes to it, once you broke the bond the car then moved.

You only have to wash your car to see rust appearing on the discs within hours.