Expert opinion required

[Crowtree]

So here is the deal, a mobile mechanic started working on my RX400H Replacing the discs and pads and front calipers, he then tells me the rear calipers were also seized and the near side rear brake hose was knackered as he could not bleed the brakes. 

I've since found out that he was probably talking codswallop as this car needs to be on a specific machine at the main dealers as the braking system is " quite complex " 

Could anybody confirm the fact with out this machine he would be unable to take this job on and complete it. 

My next course of action is the small claims court as he is not responding to any contact from me asking for a refund on the rear calipers and hose and foot brake replacement the car didn't actually need ! 

 

Any help gratefully accepted

John 

[NemesisUK]

Did you give permission for the extra work?

[sorcerer]

I've not got a 400h so I may well be talking codswallop but, I know that the 400h is built on the same body shell as the 300 and I also know that all cars have brakes. I can't imagine that there would be anything more complex or different about the brakes on the 400h other than the regenerative braking system to charge the traction Battery - the brake discs, pads, calipers and hydraulics should surely be the same as the 300 I would have thought?

If I'm right then no special machinery would be required and any mechanic should be able to get the job done easily. If I'm wrong, just ignore me

[NemesisUK]

As the hybrid uses an electric pump to create hydraulic pressure in the brake system it may be as with the SBC system in early Mercs, that there is a reservoir held under pressure and this may mean that Techstream is required to correctly bleed the system? On the Mercedes one can bleed without STAR (the MB equivalent of Techstream) but it doesn't bleed the whole system. Shouldn't  be a problem if one is simply bleeding after pad change, rather than renewing brake fluid as part of the 2yr service?

[lurch]

I believe this is the case. I always take mine to roys motor company an independent toyota/Lexus specialist , Ian there told me something on the lines above before . I'm sure he would answer your question over the phone if you gave them a call and asked for Ian 01603 424877 . Based in Norwich so can't be too far from you. Have used them for over 25 years and have been superb .

Phil.

[steve2006]

Did you retain the old, removed,supposedly faulty parts?

[Britprius]

To bleed the brake properly on the Toyota/Lexus range of cars Techstream or a suitable equivalent is a requirement. The braking system has a brake stroke simulator in it to use regen braking whenever possible. I have posted the hydraulic circuit elseware on the forum "cannot find it at the moment", but looking at this will tell you why the equipment is needed.

Further a linear solenoid calibration should also be carried out on the brake actuator when ever the brake circuit is opened.

John.

[Crowtree]

13 hours ago, Britprius said:

To bleed the brake properly on the Toyota/Lexus range of cars Techstream or a suitable equivalent is a requirement. The braking system has a brake stroke simulator in it to use regen braking whenever possible. I have posted the hydraulic circuit elseware on the forum "cannot find it at the moment", but looking at this will tell you why the equipment is needed.

Further a linear solenoid calibration should also be carried out on the brake actuator when ever the brake circuit is opened.

John.

So basically if the guy who worked on my car didn't have specific equipment he couldn't do the job and could assume the calipers were seized on account of them being " locked in place " either hydraulically or electronic ? And he would have issues bleeding the brakes so could assume the hose was faulty ? 

[Britprius]

 

It would be possible to tell if the calipers were seized, and also a visual check would show some problems with the brake hose. However it would not be possible to properly bleed the brakes without the correct equipment. It is possible to do a fudge job of bleeding the brakes "if you know how", but this is not what your paying for.

To be fair to the mechanic if he has never worked on hybrid braking systems before it would be easy to assume the braking system is like any other car, but this is far from the facts.

I managed to dig out the typical hybrid brake circuit so that you can see it's complexity.

 

John

[Crowtree]

Thank you so much for the info, I'm basically about to take the guy to court for a partial refund. I had a caliper seize on the front near side, so I decided to replace all the discs, front two calipers and all the pads. The guy started work on the car and called me out to say the rear calipers were also seized, I found this hard to believe as I'd driven back from Cornwall to Norwich the day before yes the front near side was scoring the disc for the last 100 miles but was fine to drive with care.

He showed me he couldn't push the piston back in on the rear calipers with big grips BUT I'm assuming this would be because the brake system ' locked ' so to speak. 

He also showed me the rear brake shoes for the foot brake and said they were very low on pad material BUT my local Lexus Specialist tell me these shoes are almost never replaced as they only open and close when the vehicle is stationery so they simply don't actually wear out and need replacing, he clearly didn't know these shoes only have a small depth of material and mine were actually hardly worn at all after talking with Lexus. 

As for the rear near side brake hose he could get no fluid out when he tried bleed it so again I'm assuming this is because you can't just bleed the brakes like you would on a standard car brake system ?

 

I wrote to him with registered post with a complaint and asked for a partial refund and he never responded, I wrote again and hand delivered the same letter and it was returned by the post office because he refused to sign for it ! 

 

When he had put the car back together I had some front brakes and managed limp it to the Lexus specialist who put it on their machine, reset everything including the ' Christmas tree like dash board of lights ' that had come on and adjusted the rear foot brake as it wasn't working correctly.

 

After all this and the guy charging me ten hours labour I think I have a pretty good case to take to court ! I just wanted confirmation that this car needs to be on a specific  machine in the workshop and you simply can't do this job on axle stands on the drive. 

 

Thanks guys 

[Britprius]

I think you have the answer from Lexus.

The Mechanic obviously did not know about the Lexus braking system. Brake fluid does not come out of the rear brake bleeders in the normal way by pressing the brake pedal, and as you have been told by Lexus the rear parking brake shoes have very little lining material on the when new. They also do not ware under normal circumstances as they are only used when stationary. There are times however that we drive off forgetting to release the parking brake for a short distance.

Good luck with your claim, and please let us know the outcome.

John.