bedding in new brakes
Discussion
They do say you should not use new pads and discs together but that is quite difficult.
I always bed my pads this way (car and mountain bike).......as recommended by Mintex and in my brake books.
A few gentle stops (50mph to 30mph) to match the pads to the discs, be careful not to generate too much heat.
Now do many hard stops from 70mph or 80mph down to 20mph until you can smell the pads (4 or 5 normally gets it done for me). This burns off the chemical bonding agent. Drive for a few miles after this burning process without braking to ensure every thing cools off. On my bike I ride down a big hill with the brake on.
As you use your brakes this burning process happens all the time. If you do lots of gentle brakes then another burning in process will return the effeciency.
However some pads come pre burnt, check with the pad supplier.
I always bed my pads this way (car and mountain bike).......as recommended by Mintex and in my brake books.
A few gentle stops (50mph to 30mph) to match the pads to the discs, be careful not to generate too much heat.
Now do many hard stops from 70mph or 80mph down to 20mph until you can smell the pads (4 or 5 normally gets it done for me). This burns off the chemical bonding agent. Drive for a few miles after this burning process without braking to ensure every thing cools off. On my bike I ride down a big hill with the brake on.
As you use your brakes this burning process happens all the time. If you do lots of gentle brakes then another burning in process will return the effeciency.
However some pads come pre burnt, check with the pad supplier.
Jwb said:
They do say you should not use new pads and discs together but that is quite difficult.
Do they? Where? What about new cars? A new pad will be flat. A new disc will be flat. It must surely be the fastest combo to bed in.
The best way to bed them in is to avoid prolonged heavy braking (heat), and use the handbrake: i.e. do not wait with pads clamped to hot discs as the disc may warp. Mind you, that's not just when bedding in...
Globulator said:
Jwb said:
They do say you should not use new pads and discs together but that is quite difficult.
Do they? Where? What about new cars?They do say that, but I doubt anyone ever does. As far as I understand it, bedding new pads in consists of wearing the pad to fit the contour of the disc (not an issue with brand new discs and pads) and cooking the surface of the pad. Bedding new discs on consists of clearing the surface of any contamination and corrosion and impregnating it with the material from the pads. The theory is that if you're changing discs and pads, it's best to bed in the new disc to the old pads and then fit the new pads. It's a lot of faffing about though and I don't know anyone who does it. I've never had any trouble fitting brand new discs and pads and just bedding them in as normal. Bedding them in properly is very important though, you definitely need to do this to get the maximum performance.
My AP brakes came with a full page of instruction on how to bed them in.
It is basically talking about the heat temper of the disc being the most critical so as not to warp the disc.
In brief:
10 miles light braking from 60 to 30 in blocks of 5. No heavy braking to a full stop.
100 miles increasing brake pressure. Still avoiding full stops from 70+.
By now the area around the mounting bolts should be light blue.
Further 100 mile increasing pressure then after that full stops can be used. by now the disc should be an even dark/light blue.
Track days.
One warm up lap gradually increasing brake pressure at each corner but do not left foot brake to heat things up. Cool down lap at end of session ideally not using brake at all.
Do not hold brake on at a standstill as this will locally cook the disc and cause shudder.
Steve
It is basically talking about the heat temper of the disc being the most critical so as not to warp the disc.
In brief:
10 miles light braking from 60 to 30 in blocks of 5. No heavy braking to a full stop.
100 miles increasing brake pressure. Still avoiding full stops from 70+.
By now the area around the mounting bolts should be light blue.
Further 100 mile increasing pressure then after that full stops can be used. by now the disc should be an even dark/light blue.
Track days.
One warm up lap gradually increasing brake pressure at each corner but do not left foot brake to heat things up. Cool down lap at end of session ideally not using brake at all.
Do not hold brake on at a standstill as this will locally cook the disc and cause shudder.
Steve
steve_d said:
Track days.
One warm up lap gradually increasing brake pressure at each corner but do not left foot brake to heat things up. Cool down lap at end of session ideally not using brake at all.
Do not hold brake on at a standstill as this will locally cook the disc and cause shudder.
Steve
LOL, I've never seen anyone do a warm up lap on a track day, nor a cool down lap! (well hardly anyone!)
combemarshal said:
LOL, I've never seen anyone do a warm up lap on a track day, nor a cool down lap! (well hardly anyone!)
I always work up gradually on a track day and always cool off before the end of the session, and plenty of others do the same. Perhaps not so common at Castle Combe?
GreenV8S said:
combemarshal said:
LOL, I've never seen anyone do a warm up lap on a track day, nor a cool down lap! (well hardly anyone!)
I always work up gradually on a track day and always cool off before the end of the session, and plenty of others do the same. Perhaps not so common at Castle Combe?
Trust me, they don't!
A good reference on brakes and their bedding in can be found at:
www.stoptech.com/tech_info/wp_warped_brakedisk.shtml
the whole article is very good but the generic bedding in procedure is in the 'Prevention' section. Certainly saved me replacing my disks before necessary.
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