New Disks / Pads - Bedding In
 

What the process for bedding in :

1. New Disks & New Pads
2. New Pads & Old Disks
3. New Disks & Old Pads

Ideally I want the answer to Number 1, but thought this is as good a place as any to answers to all 3.

I can never remember which requires which process i.e hard and fast or slow and gentle. I know what the :wife: prefers........;)

Silly question?

Why would you have new discs and old pads, Id have thought bad practice ?

Hard and fast is good to avoid a lot of heat build up ? but I am no mechanic..

That could make the pads glaze though,doesn't it depend on the make?


I once had new stop tech brakes on an m3 and they wanted high speed hard braking then cooling off, repeat several times but others have been different:deadhorse:

If I remember right when I used PF pads they took some bending in. Varying speeds & hard on the b peddle. Very good pads though.

I like mine :nod:

when i bed new brakes in i normally press the brake pedal gently while driving along to take the top surface off mate.

I've allways been told new discs if you brake hard you'll warp them straight away

With the new ksports i went gently on them for the first couple of hundred miles to let them bed in. Then put a few 70 to zero stops on them, but guess that wasn't enough as they faded badly on my first lap of the Ring this year. After that, they came back nicely and were great at Goodwood.

But i wouldn't give them a load of heat cycles straight away, go easy for a bit first i'd say.

From the Ferodo site

During manufacturing, all Ferodo racing products are subject to “chemical bedding” to stabilise the materials and resins used in construction of the pad. Although this “prebedding” is an effective method and sufficient for low temperature use, the ultimate results are achieved by actual bedding on either the car or dyno...
*
How ? ...
This subjects the pad to the correct heat and torque loads seen in race conditions. These methods transfer pad material into the face of the rotor leaving a “transfer film” the friction generated between the pad face and this transfer film determines the performance of the “bite”. Correct bedding also ensures that materials which may become compressible are stabilized with the heat and pressure to avoid a “spongy pedal”.
Why? ...
When bedding in the car always try to bed on used rotors. If bedding on new rotors follow the rotor bedding instructions of the manufacturer, as it is important to heat cycle them first before bedding the pads. After fitting the new pads prepare the car by blocking off 50 percent of the brake cooling / air ducts to speed the “heat up time”. When leaving the pit lane apply brake gently at low speed to ensure pads are fitted correctly, build up temperature progressively to approx 350° C (670° F). This enables the heat to distribute around all areas of the pad.

When brakes are at suitable temperature begin bedding process, achieve approximately 70 percent of race speed then perform 25-30 brake applications at half normal race pedal pressure holding on for 4 seconds.
When this is completed use a slowing down lap to allow brakes to cool. Return to the pit lane and allow pads to cool completely, check rotor appearance. Transfer film should be constant around rotor face, any “patchy” deposit will result in brake pedal judder. The use of temperature paint on rotors enables more accurate bedding procedures.

**at all times when "bedding" make sure you obey local speed limits and respect other road users**

unless your using something like Performance friction discs (which are heat-treated as std) then you will have to condition the discs!!
do NOT be tempted to follow the race style bedding of short sharp shock treatment or you will most likely warp the discs or at min shorten their life

in general just use the brakes "reasonably" with no excessive or prolonged braking for the first 100-150miles, then for the next 50miles gradually build up the strength and length of the stops until you are using the brakes virtually to their full effect.........

the 'Quickfit' type recomends about having to fit new discs and pads as sets is simply an up-sell in basic terms - as long as your pads or discs have no strange wear marks or angled patterns then ideally you would fit new discs to old pads and vice-versa due to the potentially differing bedding needs

for the race/rally cars we can often simply use time to pre-bed new pads on used rotors and also then bed a spare set of rotors, etc. so they can be fitted & used instantly if required