Stoptech front big brake kit - can i move this to the rears?

[DavidR]

The fronts are really easy, there is a bridge held by two bolts and then the old pads lever the pistons in.

The rears are Audi standard discs and pads I fitted over summer. I cannot see the point of uprading them as their overall influence on the brake setup is fairly minimal.

[Stevo]

I just downloaded the pdf's from stoptech, thanks again to everyone.

Steve.

Another question on another topic though i will ask here as well

Does anyone know if there is a handsfree mic built into the trim of the 1999 b5 S4 facelift model?
It mentions this in the bentley CD manual i got of ebay, i'm trying to sort out a nokia handfree kit for the car.

[BW]

Bem

I wonder Stoptech on your car is four indentical 4 piston caliper ST40. 28&30mm.

You sure the rear and front has differnt dia. piston in your kits???

They must have shift a litter bit of rear bias per your rotor sizes; [355x32mm and 328x28mm rear floating directional slotted rotors, 4 ST-40 four piston calipers painted ]

Regards

[Stevo]

Well installed the Pagid blues last week on the front.
I did 2 bed-in runs and after a couple of days the front drivers side brakes started squeeling and making a bad grinding noise.
I looked at the disc and there was a distinct marking all round it. I took the wheel off and the pad had some bad sharp edges on it and had to sand them down, I also ran my finger down the surface of the disc and it was not smooth, more like a rippled surface. The brakes are now fine and a definite improvement.

[Stevo]

Bad news.
The grinding and squeal noises have come back again.
The stoptech procedure for bedding in the pads is totally different to that of the Pagid bed-in procedure and it mentions that during an initial pagid bed-in procedure that the pads should not reach temps above 400 C and i think i maybe went above that following the stoptech bed-in procedure.

When i took the pads of last time the pagids had a 2mm glazed shiny layer on them.

Any ideas on how to rectify this?

Steve.

[DaveP]

Here's my guess...

Is there still a rippling on your discs ? If so, maybe your discs are causing the pads to cut up (you mentioned sharp edges on the pads?) - when you sanded the pads they were ok...but now they've cut up again due to the discs not being smooth??

[Stevo]

Yep, thats correct Dave.
Thing is i didnt file the edges down when installing the pads initially.
Is this normal, the discs having a rippled feel when i rub my finger from the edge towards the hub?

Steve.

[DavidR]

Squealing is normal and not worrisome, although can be annoying - I make sure that all parts of the pad in contact with the caliper are copper slipped (or have similar antisqueal compound fitted)

The grinding sounds bad - ripples? Sounds like the discs cracking? I would be very surprised (Matt pretty much guranteed the discs against radial cracks - and recommended the grooved ones over drilled for that reason) but grinding that appears once the brakes get hot points to cracks (they expand when hot = noise). Check the disc surface carefully, looking for tiny wavy cracks in a radial direction on the disc face - if you see them, you have your answer - fortuntately the brakes are still under warranty...

Re bed in, I wouldn't have thought that stoptechs bed in procedure would get temps much over 400degrees, certainly they recommend bed in with ANY pad using their instructions. The grey area can be normal, its where the binding compound in the pad has melted and reset (noticeable by the smoking and smell on the 1st bed in run) and indicates a successful heat cycle.

Give me an email / phone Steve if you have further issues - I may be able to help.

[Stevo]

Its just at slow speed in traffic i.e when coming to a stop at traffic lights, i apply the brakes lightly then they squeel a lot then apply the brakes a little more to bring the car nearly to standstill and thats when i get the grinding noises.

I dont get the squeals and grinding at higher speeds when braking to come of a dual carriageway but i'm getting the occasional solid fading when braking at higher speeds.

Thanks guys.

David, i'll give u phone.

Steve.