Proper Brake Pad Bedding

n8marx · n8marx's Garage

I give up. I once saw a post by Warren that detailed a procedure for properly bedding new brake pads. I can't find it now. What procedure, if any, do you folks use to ready your brake pads for use?

I just installed 4 new rotors on my '86 Carrera and intend to install new pads as well. I have heard that I need to "season" the new rotors with the old brake pads and then properly bed the new pads. Is this true? Why can't you just bed the new pads on the new rotors? What's the skinny?

I need your help here. Please keep in mind this is a street car that will see a couple of track days and probably some auto-crosses this year.

TIA

jmohn · jmohn's Garage

I've never heard of "seasoning" the rotors, but I can give you Repco's description (from a few years ago) of proper pad bedding --- brake heavily (don't lock them up) from 60-70 MPH down to 20-30 MPH several (6-8) times, you should feel the brakes fade at some point during this exercise (the fade tells you the pads have been heated enough to off-gas, I never really felt them fade, but I could sure smell them), then drive for several (15-20) minutes to let the rotors and pads cool, then repeat the braking procedure once again, drive to cool off, and you're done.

Jerry M
'78 SC

Eric Coffey · 11:30 AM

The idea is to bring the pads up to maximum operating temperature (somewhere north of 500 degrees F) very slowly, but NOT overheating them. Here's a good procedure for street pads: After installing new pads, find a close, open stretch of road. Drive for about a 1/4 mile at 35-40mph, while slightly dragging the brakes. Now, drive for about a mile with no brake pressure to let the pads cool, then perform a light/medium (40mph-0) stop. You're done!

Also, it would be a good idea to install rear pads first (keeping the old fronts) and bed them in using the above procedure, except lengthen the initial brake drag to a mile at 50-60mph, and increase the final stop to a 65mph-0 medium stop. If you smell anything funny, don't worry, it's just your old front pads being tortured!

There is also a "High-speed" bedding procedure for high-friction/racing pads:

Do 4 medium, gradual stops from about 90mph-60mph, with 1/4 mile cool-down periods in between. Then 1 heavy stop from about 110mph-60-mph. Finish with 2 light stops. Repeat this procedure 2 times.

Also, if you are re-using your discs with new pads, make sure to lightly sand them to remove old pad material/glaze.

Eric Coffey · 02-04-2003, 11:33 AM

I have never heard of "seasoning" rotors with the old brake pads either. It sounds like the opposite of what you should do! You do not want to mix friction materials.

Doug E · 02-04-2003, 06:16 PM

Eric - why do the backs first?

APKhaos · 02-04-2003, 07:44 PM

New pads? This is Peter Tremper's method:

Get some highway. Cruise at a comfortable highway speed - check the revs. Maintain throttle with right foot, left foot brake to gently reduce speed by 1000 revs. Release brake, get revs back to cruise. Repeat until you smell the brakes - 3 or 4 times. Done.

Objective is to burn off the uncured resins in the pad material. Learned this after driving to VIR with new pads [thinking the drive would bed them in] and having them grab and jerk on the track. The rotors were covered in pad spooge - a nasty varnish that took some work to remove.

hgray · 02-04-2003, 08:50 PM

Try this link to Baer Racing Brakes.... in the tech section they have an article on rotor seasoning and pad bedding.

http://www.baerracing.com/Showcase/TechTips.aspx

Eric Coffey · 11:39 PM

Doug E-

Due to the strong front brake bias, the procedure for bedding the rears (in my previous post) requires more time/distance/speed to bring them up to the same temperature as the fronts. You want to do this with the old front pads, so you don't "over cook" your new front pads.

P.S. - if you want to avoid that issue altogether, just get a dual-master cylinder setup with adjustable brake bias so you can set it to 50/50 when bedding in new pads!