Hi Roy
I have not been familiar with the term of bedded in breaks before.
I just read a little about it, and I have to say that I have not done anything to bed the breaks in properly. I actually have to say that I thought that new breaks would bed in by them self during every day driving. Guess I was wrong..
How do you bed-in your breaks, Roy?
Hello Frederik,
This partly depends on whether the new pads are against old already used discs or fitted at the same time as new discs, as in your case. When new pads are being fitted with new discs they should both have nice flat surfaces and consequently bed-in much quicker. With already used discs, the surfaces will have small (or sometimes large) grooves and the pads will take a little longer to wear to a corresponding shape. Until the surfaces match, the peaks of the metal will cause the pad in contact at that point to get very hot as a lot of the pad area is not yet touching to spread the load.
The aim of the bedding-in period is to bring the new pads up to working temperature gently over a small period. So the speeds should be kept low (no more than 50 kph and light or gentle and short braking periods, so they don't heat up too rapidly. Do this for between 80 and 200 kms. I usually fit mine then use the car in and around London where the speed limit is often 50 kph anyway so it is easy to stick to that; and leave plenty of room so you can do short gently applications. Used discs will mean the pads take a little longer to wear to the discs, new discs mean they should bed-in faster. Obviously if you did have an emergency then you would have to use the brakes accordingly, but if you are driving correctly at low speed and leaving plenty of room, you should not have an emergency anyway!
If the pads are used at higher speeds or in heavy braking, they will heat up too quickly and may become glazed which will cause a loss of efficiency. I once tried some of those brake dust shields (as an experiment - not for me as I never liked them but for other club members). They fit behind the alloy wheels to keep them cleaner, but they also caused the pads to glaze/loose efficiency because they became too hot. I described this in our magazine and said owners should not use these dust shields because they stop the cooling air flow.
The Discs and pad I am using are standard from my local parts dealer. The pads might also be of some age, if the have been on the shelf for 20 years, but can age alone deteriorate pads?
Yes age can cause a deterioration in the pads. Usually they get harder and have less efficiency - especially with these horrible non-asbestos pads. The older asbestos pads were much better but we all know they stopped these because of health concerns. (however the non-asbestos pads are not a lot better because of the excess black dust they produce!)
My view is the Kevlar based EBC greenstuff pads are what you need today. Similar to the old asbestos, less disc wear, less dust than the latest pads, 20% better braking too.
Roy