Sticking calliper. Damn. Oh well, new discs and pads on the rear then.





C

 

It's probably worth replacing the stainless steel slide clips at the same time. They're 3D0615231 or Mintex MBA1610.
I'm amazed that the slide pins 3W0698470B aren't expensive - £13 per vehicle side at Scuderia - so I think I would replace all those as well.

 

Thanks. I expect they will be. It's in the hands of my Indy, and he's very good.

Cheers

C

 

Interesting why the low pads light never came on ? It suppose ( the rear set )to be a preprogrammed time of the motor run of the EPB .The longer it spins distance wise the motor the less pad thickness ……something like that .Pad thickness dialled into the “computer “ @ fresh pad day .
Std VAG rear EPB brakes .
Second interesting point - the inner on the pic has worn faster but I bet ( not shown ) the inner disk surface is hardly worn , scored / light corrosion?? This is most peculiar as the piston is inboard yet the out board , the carrier side always looks as disks should nice and shiny and smooth.
Assuming the sliders are properly greased up .Stiff sliders ( special brake grease ) could mean the outboard disk gets LESS pressure thus the uneven pad wear .
I think @ service annually they should pop the pads out and clean up the sliders , you can ease back the rubber boots to check.Also ideally pop the pads and clean up / lub the whole lot applying copper slip to the pads ears in the carrier .Too much dust / grime and the pads ears could jam .

Wonder how many service guys ( or home DIY ers ? ) actually do a full brake strip , clean , lub and refit if ok pad thickness annually ??

Brembos , the multi pistons in each side of the caliper are pretty much fit and forget until the pads need replacement.There’s nothing to ceases up or clean up regularly.
How ever these piston on one side the inner + a slider + external carrier require intervention between pad replacement to clean up and lub the moving slider pins .The fronts on the B are twin piston the rears single piston btw .

Thirdly you can with the assistance of a little hand ( large dentist type ) mirror get a look at the pad thickness, both sides to keep an eye on pad thickness without removing a wheel …….at the very least if you are not into DIY ing .Ie Jack mode removing wheels doing a brake service properly.

They are dead easy theses VAG brakes plenty of u tube vids of guys doing pads in less than 5 mins once the wheel is off .
The simplicity of the BGT brakes does make up for other complicated stuff ……refreshingly simple for a change.

Without sounding critical there is really no excuse to let the inner pads get like that .

 

The piston just needs working back and forth once the caliper is off .Remove the logo plate and use the retractor set with a pad to act as a disk .
Exercise it all EPB . Do my 12 v bat trick .The rest of the car will be unaware the EPB motor is working the piston in / out .

Same for the slider pins , clean them up and lub them with the special brake grease .

As I said no bodies been in there for years basically = cease up .


Pics in this thread I did last winter .
https://www.6speedonline.com/forums/...otors-bgt.html

 

Surely the EPB travel distance is not a function of pad wear (I assume it uses the same pads) unless the EPB loses contact with the back of the pad? The pad <> disc clearance should be pretty constant throughout the wear of the pad. I may be missing something.

Totally agree it's easy to check. Last time I checked there was no issue. That was <1000 miles ago. Few high speed motorway trips and there we are. No idea what the inner face of the disc looks like, but I'm sure Danny will do the right thing (and get everything lubed back up again!)

C

 

It’s calibrated from the new pad fit day , or should be .Not each individual on / off cycle .
So say 13 mm is used as a calibration number .As the pad wears the piston moves out mm by mm as time goes on .When it’s reached 11 mm from the initial start ( newpad day if calibrated ) the light supposed to come on .
Assuming in this example 13/14 mm so 2/3 mm left .
Of course in each individual on / off EPB cycle it just retracts it a mm or so , but the ECU knows where it started so is counting down to 11 mm in theory from a pad thickness of 13 mm .

Yours must have been poor poorly calibrated for the metal rivets to become exposed .Chances are the inside surface of the disks are scored .

Thats a grey ish area on U.K. MOT a ( for US guys that’s an annual kinda road worthy check ) .
Anyhow cheap as chips the rear disks as they are a very common German auto part , BMW s as well as VAG products .

In my post ^^^ the rear disk replacement, I obviously did not re calibrate , the ECU still thinks / remembers what the last guy ( A Bentley specialist who did the pads ) entered last time .It’s oblivious to my intervention.

Thats why I am not waiting for the dash light , because I can’t for sure exactly know if it’s gonna light up @ 2/3 mm or proceed to score the inside of the disks .Obviously every car wash any fool can eye ball the external disk surfaces even eye ball the pad thickness if you know what you are looking at .

 

There is no cross part for the front disks ( rotors ) they appear unique to the BGT and priced accordingly .= expensive!
How ever the inside pads have tradition wear sensors fitted , so GDN out at 2/3 mm or what ever and pop a dash light on .

 

Gotcha. Very clear, thanks!

C

 

The rear disc's on the Bentley are the front disc's of a audi A8 (same part numbers) got some in 2019 to do mine.

 

All done now. Discs were £150 of my British pounds.

C