Caliper problem?

[Masiv44]

Brand new discs and pads put on in October.  One is doing a full, even sweep of the disc, but the other seems to be applying more pressure and only to the main central part of the disc.

 

The shiny disc was slightly warm after driving for a few miles, while the other was cold.

Everyone think the caliper is f#[]#[[?

[NemesisUK]

Looks more like the pad is at fault. 

Who fitted the pads and discs?

[katabrontes]

Looks as if it's the pad being a bit proud in the centre (unless two big chunks have fallen off each edge!) Surely the pad will wear a little and then bear evenly on the disc.  Seems pretty unlikely that the caliper is at fault as it is pressing the pad centrally against the disc.

[Masiv44]

33 minutes ago, NemesisUK said:

Looks more like the pad is at fault. 

Who fitted the pads and discs?

Main dealers, when I bought the car in December.

 

The thing is, that soon after I bought the car I was looking through all the service print outs and noticed that the service they did just before I bought the car  said there was very uneven wear between the two rear sets of pads. 2mm/7mm iirc.  They only replaced the discs and pads. The service sheet stated possible caliper fault, but they didn't replace it.  I contacted their service department and they said that 'calipers were within tolerance.'  

 

I'm just being very aware, that the further it gets from me having purchased the car, the harder it'll be to get them to replace it if it is faulty.

[Spock66]

Could be the slider pins rather than the caliper itself.

[cdmaskell]

Contaminated pad at extremities?

[NemesisUK]

2 hours ago, Masiv44 said:

Main dealers, when I bought the car in December.

 

Take it back and ask them to rectify it or if they state there is no problem, get it in writing.

[Brian26]

Hi Michael, It may be worth contacting Lexus customer services as I think it shows very poor customer support on behalf of the dealer. You may be surprised if they do get involved.

Bri

[HPS13]

On the lower photo that you posted you can see evidence of excess heat damage due to the caliper binding. With the symptoms you describe - previous uneven pad wear recorded and at present, one caliper is hot and the other is cold, the following would be parts to check / replace. 

1. piston(s) in the caliper is partially seized.

2. Sliding pins are seized inside the caliper preventing the caliper from moving. 

3. Flexible brake hose is perished internally and causing the caliper to bind on. 

[Masiv44]

1 hour ago, HPS13 said:

On the lower photo that you posted you can see evidence of excess heat damage due to the caliper binding. 

Do you mean the colour? 

[HPS13]

Yes, if the photo is accurate. Looks like the disc has overheated. 

[VFR]

Odds on (as has been said) that the slider pins are not working as intended.

An easy fix if you have the tools etc but as you paid a “dealer” get them to sort it. 

A caliper in most cars has a piston only on one side, so that is doing the work to squeeze the pads onto the disc, it does though rely on the the sliders to exert the same squeeze onto the other side. 

Bit of friction, not sliding as they should, contamination, no correct grease etc etc & etc you have what the pictures tell us.

[Masiv44]

2 hours ago, HPS13 said:

On the lower photo that you posted you can see evidence of excess heat damage due to the caliper binding. 

Do you mean the colour? 

[HPS13]

Yes the colour and also the shine on the disc. 

[Masiv44]

I'll get onto the dealers today. If they did the sliders when they checked / serviced the brakes then why would it be causing a problem so soon? 

Rather than start a new thread, can someone tell me or point me in the way of how to change the unlock feature on the remote from open the driver door to open all doors? 

[steve2006]

You may find this hard to believe but unless specifically requested the slide pins are generally not removed and re-greased during a dealer brake service.This often results in the Lexus seized calliper problem which I strongly suspect is the cause here.

The only specific parts of a brake calliper alone that can seize are the pistons and the pad slides as these are the only moving parts in it, the only other moving parts are the slide pins…. the usual cause.

I have never heard of any 4 pot callipers seizing up the reason probably being that these do not have slide pins.

Do you have any other symptoms like juddering brakes or pulling to one side?

[Masiv44]

No, all seems otherwise fine.

[Masiv44]

8 hours ago, steve2006 said:

You may find this hard to believe but unless specifically requested the slide pins are generally not removed and re-greased during a dealer brake service.This often results in the Lexus seized calliper problem which I strongly suspect is the cause here.

The only specific parts of a brake calliper alone that can seize are the pistons and the pad slides as these are the only moving parts in it, the only other moving parts are the slide pins…. the usual cause.

I have never heard of any 4 pot callipers seizing up the reason probably being that these do not have slide pins.

Do you have any other symptoms like juddering brakes or pulling to one side?

Wow! My local guy would clean and regrease as a matter of course when doing a brake service on my cars. 

[Malc1]

At every annual service I specifically ask my Indy service guy to overhaul the calipers, make sure they’re properly functioning ……. and in 248k miles, 29 years,  I believe I’m on  “ originals” 

I’ve never seen a bill for replacement calipers whatever 

Malc