Brake Issues

[Nikey30]

Hi All

I am seeking some advice on a current issue I have with my front AP BBK. I have recently swapped from AP discs to Performance Friction due to a vibration/pulsing on the AP discs which led me to believe I had warped them - even though I have never tracked my car. Anyway I have had the PF Discs on for approx 1500 miles (road miles only) and in the last few weeks the pulsing/vibration has returned and when driving yesterday the vibration was that bad that when braking lightly at lowish speeds I could here a slight knocking, obviously something isnt right.

So I pulled one of the front wheels off last night and have taken some pics of one of the discs and I also removed the one of the pads to see what could be causing this problem. I am running Pagid RS14 pads and these are the same set that I ran on the previous AP discs.

Should I have put new pads on when I put the new discs on the car?

From my investigation via the internet I think I may have pad deposits on the discs and the pads are potentially glazed. Can anyone take a look the pics and confirm if I am correct? I am no expert but would think the discs should have a cleaner/shinier look?

If this is the case then obviously a new set of pads are needed, I know that an agressive pad can clean discs up and remove deposits, so I assume the Pagid RS29 would be a potential option? Or do I need to get the discs removed and cleaned up at an engineering shop prior to the install and bed in of the new pads?

I would really like to get this resolved as I feel I am going round in circles with the brakes on my car.

Any guidance appreciated as I dont want to use the car at present due to the vibration as concerned its going to cause other issues within the steering/bearings etc.


Thanks
Nick

[alexk]

Nick,

Start with installing the discs properly.
What you are showing in the photo is the front left arm.
This disc should be installed on the right side...

[shane@mbtech]

Looks like pad deposits to me.

Get some abrasive pads in to clean them up.

[shimmy]

I had troubles with my AP back in 2007-2008 a number of times, always thinks it was warped and ended up being pad deposits.

I think you have used old pads that are thicker in the middle and this has deposited pad material of the centre of the disc.

Not sure how to fix but I would be tempted to buy new pads, and either skim of sand down the discs to remove deposits and bed them in again (and then swap the discs around )

Prob best to do it before the discs are goosed

[CraigMillwardCroft]

Has anyone got running in details for Pagid RS29 going to try and put them in today. :thumbs:

[The Gorilla]

Hi,

You should always bed new Discs and
Pads in.

Its boring and takes a little time.

I always take New Discs through the heat
cycle as well to make sure they get nice
and blue.

With regard to the discs in the picture
as Lawsy said they need cleaning with
an Abrasive Pad.
Carbon Tech or Carbo Laronie's will soon
rip it off, but are not cheap.

Or have a light 'skim' to clean them up.

Regards,

The Gorilla.

[Pooky]

As said above all the Pagid RS range need bedding properly, instructions for this are on the Pagid motorsport website. Just running on the road won't bed them, you need the proper heat cycles to build up the transfer layer.

The deposits are caused by not having the transfer layer and then high friction causing high surface temperatures.

Running your discs backwards won't be helping temps either...

[O'Neill]

I remember reading when using a race pad gently ie lots of road use, you need to go through some bedding in cycles before using them hard again or you'll get exactly what you're describing :thumbs:

[83SY]

Has anyone got running in details for Pagid RS29 going to try and put them in today. :thumbs:

I drove to Spa, bit excessive but bedded in nicely! :-D

[CraigMillwardCroft]

I drove to Spa, bit excessive but bedded in nicely! :-D

I will run them on my local bypass, that should do the trick :whistle:

[northernjim]

Has anyone got running in details for Pagid RS29 going to try and put them in today. :thumbs:

Guidance On Bedding In Procedure

Geometric Alignment Of Pad Surface To Disc Surface (basic bedding in)

4-6 brake applications with medium pedal pressure from approx 90mph to 50mph, not allowing wheels to lock. (No brake dragging)

Allow for a distance of 300 - 400metres between brake applications for cooling period.

Pads should not reach temperatures above 400°C during initial bedding in. Check that pad
surfaces have at least 80% contact with disc before allowing more heat into pad surface.

Immediately followed by :

Bedding In At High Speed

1 brake application with medium to high pedal pressure from approx 110mph to 50mph
without allowing wheels to lock.

Allow 3-4 recovery brake applications with light pedal pressure.

Repeat high speed applications including recovery applications another 2-3 times.

Allow a cooling off distance of 500 metres between high speed applications.

*



I've found pagids a little tricky to bed in, for me it works to just use the car normally/gently for a few miles, and then follow the bedding in procedure.

[Equinox_csl]

Depending on how much pad transfer you have on your discs you may end up re-facing them, if you do then fit a new set of pads they will be perfect. Common cause of pad transfer is either keeping your foot on the brakes after using them at a junction or something like that or if the car stands for time outside water will sit between the pads and the discs and can result in the same effect, slight vibration when cool but terrible when hot and would need a re-face.

Hope that helps a little.

Equinox

[Nikey30]

Hi All,

Big thanks for all the comments. As you can imagine I am not happy with the garage that put the new discs on - to now find they have put them on the wrong way round :bigcry:

Anyway I will get a set of Rs29's ordered first thing in the morn and get the discs off for a skim this week, then hopefully I will have some decent stopping power!

Cheers
Nick

[phoenixcsl]

Are my pf discs round the wrong way too? :clown:

[CraigMillwardCroft]

Going by the first thread on this subject yes if Performance Friction Disc's. What does there website tell you or install leaflet :thumbs: