Bedding in new brakes and discs what procedure?

[rob8457]

Just fitting new discs and pads to a mates car what is the best procedure for bedding in the brakes and discs, it seems everyones opinion differs.

Bobby

[HYFR]

just do loads of massive stops from 70 - 100 mph down to 30 / 40 .... with time in between to let them cool

you want to get sufficient pad transfer to the discs.

[sonny]

Im not being pedantic but im
Sure its the other way round, lower speed braking followed by high speed braking.

Irrc its around 30 low speed and 10 high speed breaking procedures.

I posted the Audi bedding in procedure, do a search it should
Pop up

[Shoppinit]

This is what I do:

1. Warm up the brakes with some gentle braking.
2. 10 big stops from 60 to 5mph. I don't mean slamming the anchors on and letting the ABS take over. Brake as hard as you can without the ABS kicking in.
3. Drive for a while to let the brakes cool down. Do not at any point stop dead with the brakes on or use the handbrake.

Some pads can't handle 10 big stops. If I get fade or they start smoking / catch fire before then obviously don't continue.
Works for me.

[rob8457]

Just done a search but still confused as there is still no definite procedure to bed em in properly, have Audi got a spec on it?

Bobby

[adsgreen]

Shoppinit's method is accurate and not far from audis own recommendation. IIRC audi state lower speed and more stops but the net effect is the same.
Only (minor) tweak would be to change "gentle" in step 1 to "firm". Nothing major - think the kind of deceleration you get in 1st gear when you let off at high rpms. Enough that a passenger would notice it as you need to make sure heat is getting into all the system and not just the high spots. Very easy to brake too lightly in these cars given the huge braking capacity.

Also remember that when you are braking from high speed its better to push on the pedal not stamp. Once you start braking and the load transfers to the front wheels you can add more and more braking without lockup. Try the same pedal position/force too quickly and the wheels will try to lock.

If you're worried about overheating then break it up into 2x5 stops with a 5 min cool down in between.

Alternatively get the car on a trackday - by far the best way to bed in pads.

[Shoppinit]

Alternatively get the car on a trackday - by far the best way to bed in pads.

And wear them down to the metal, all in one go.

[Mr Footlong]

Carbotech's take on bedding their pads in at least, is shown here - http://forum.rs246.com/viewtopic.php?f= ... 30#p509779

[Nobby]

This is what I've used for quite a few years - and came directly from Pagid.

GUIDANCE ON PAD INSTALLATION

When installing Pagid Racing Brake Pads, we recommend you observe the following:

CLEANING DISCS

It is always good practice to clean the surface of the disc to remove any previous pad deposits and contamination.. This is best done by having the discs surface ground,, if this is not possible clean the disc surface with a medium grade emery cloth.. This will all low the new pad to achieve better contact with the grain off the disc surface.. As many high performance friction materials impart a friction transfer layer on the disc surface, this should be cleaned away when new pads are fitted.. This is especially the case when a change off compound is made. Failure to clean the disc surface will result in reduced friction and reduced brake pad life.

MOUNTING NEW PADS ON USED DISCS

When fitting new pads to used discs care must be taken to file the top and bottom edges to 45to allow pads to clear high ridges on disc radius. This will allow the pads to fully contact the disc surface. If the contact area is reduced, hot spots can occur and damage friction material reducing efficiency. If you are changing to Pagid RS pads from another manufacturer, please take care to remove all surface deposits from the disc. If this is not done, bedding in may prove difficult and reduce life and performance of the pads.

BRAKE DISC CONDITIONING (NEW DISCS)

When fitting new discs care must be taken to heat cycle the disc by gradually introducing moderate temperatures into the disc before high temperatures are reached. The introduction of high temperatures into the brake disc too quickly can result in thermal shock causing cracking and disc distortion. Thermal shock can be reduced by also allowing the disc and pad combination to cool gradually after extreme use, and allowing the vehicle to come to a complete stop when the brakes are at extreme temperatures should be avoided. (Holding vehicle in the pit lane on the foot brake). Thermal shock can result from the level of thermal energy applied, or from the rate the heat is applied and removed. Try to keep the energy levels gradual by using warming up cycles and cooling down cycles where possible. This practice will prolong the life of both pad and disc, improve overall brake performance and help to prevent failures.

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.

[HYFR]

just take the car to Brands Hatch ... that was I did on my last set of new pads/discs ! LOL

[rossi46]

FWIW, Audi told me the following ;

Suggested procedure for fast road/track use ;
60mph > 20mph Light braking , 50 times
60mph > 20mph hard braking (no abs) 50 times
60mph > 20mph hard braking (ensuring abs kicks in) 10 times
A 2min gap between EACH run is required.

[Shoppinit]

That's more than 3 and a half hours to do bedding in?! No thanks!

[bam_bam]

FWIW, Audi told me the following ;

Suggested procedure for fast road/track use ;
60mph > 20mph Light braking , 50 times
60mph > 20mph hard braking (no abs) 50 times
60mph > 20mph hard braking (ensuring abs kicks in) 10 times
A 2min gap between EACH run is required.

That sounds like 4 laps the N-Burger.

[rob8457]

See what i mean everyone says different come on Footlong - Bam bam - Shoppinit put me right hear as still confused.com

Bobby

[bam_bam]

See what i mean everyone says different come on Footlong - Bam bam - Shoppinit put me right hear as still confused.com

Bobby

*here

Footlong should be discounted (no offence) as he is referring to CarbonTech.
I should be ignored as I had nothing meaningful to add.
Shoppinit's advice is usually sage (except when trying to steer you around Bangkok).
Mr. Green and Sonny are both in the same boat as Shoppinit but know even less about Bangkok.

You could de very little better to follow either Shop, Sonny or adsgreen's advice. Stop being a pussy and get out there.