Modern Brakes Fitment and ‘Bedding in’ Guide
Welcome to the Modern Brakes Fitment and ‘Bedding in’ Guide
The automotive industry is fast changing in all areas – not the least brakes!
Aftermarket demand for OE quality replacement parts, often indicated by quality assurance standards such as ECE R90 (European standard) or ISO9001 (International standard), is ever increasing, and in my opinion this is a very good thing!
This market demand has led manufacturers to look at new ways of producing and ﬁnishing products and also led to new technologies being used in aftermarket brake replacement.
We are now seeing brake rotors from many leading brands being ‘coated’ in an anti-corrosion material that has some beneﬁts:
- Fast ﬁt – no “pre-cleaning” required
- No oxidation in the ﬁns – providing better heat dissipation while braking
However, these coatings also have drawbacks when rotors are not installed and then ‘bedded-in’ correctly.
We are ﬁnding that a number of customers have the same complaints when replacing disc rotors and pads, these are –
- Pads seem to be taking longer to bed-in or “not working”
- Squealing or excess noise
The days of ﬁtting rotors, cleaning off the anti-rust coating, installing brake pads then hitting the road to bed-in the brakes via 4-6 medium to hard brake applications – you know the old “Get a bit of heat into ‘em” method, are LONG GONE! The new coatings on rotors and, now seen in a large number of brands, ‘bed-in coating or strip’ on brake pads, along with new technologies in friction material (pads) and metallurgy (rotors) means that we have to use different techniques when installing and bedding-in brakes.
The New Way
1. DO NOT apply brake clean or the like to any coated rotor – these chemicals will break down the coating, forming lumps on the pad contact face which leads to DTV (= Shudder!)
2. Clean and lubricate caliper slides, also lubricate the back and end of the brake pad (sparingly, wherever it contacts caliper and bracket) with an approved, high temp brake caliper grease. This allows the pad and caliper to move and slide freely, which helps eliminate vibration and as we all know – vibration is noise!
3. Bedding-in brakes is all about getting the pad material to “talk” to the disc rotor material. I know this sounds a bit out there – but, under a microscope brake pads that are bedded in correctly deposit a transfer layer of material into the disc and vice versa! When bedding-in on the road it is absolutely imperative not to get the brakes too hot too quick! At ﬁrst think clean, like a windscreen wiper, the bed-in coatings on pads are there to help clean the coating off the rotor face. If you get the brakes too hot straight away you “cook” the coating into the rotor and pad face which leads to “glazing” of the rotors. This also means that the pads and rotors aren’t “talking” = poor pedal feel/pads aren’t working, and noise.
Today‘s Modern Brakes Fitment Bed in Procedure
So, with all of this in mind the Modern Brakes Fitment ‘bed-in’ procedure to follow is
- 4-6 very light braking applications, do not stop the vehicle completely (60kph to 40kph), think clean – NOT HEAT! Then progress to 4-6 light braking applications (60kph to 20kph) allowing at least 300m between applications.
- After this, drive the vehicle for a few k’s under normal trafﬁc conditions using the brakes appropriately. Then – a ﬁnisher, 4 medium braking stops (80kph to 40kph) also allowing 300m between braking stops.
- Finish your test drive under normal conditions. Advise your customer that it will take up to 500km of normal driving conditions to fully “bed-in” their new brakes and advise them not to get them unnecessarily hot during this time. Take your time during the initial bed-in process, a longer test drive.
By following these simple procedures you should experience very little, if any, trouble when ﬁtting modern day brake rotors and pads, regardless of the brand.
Yours in automotive, Ben Falcke