OT - Can You Bed Brakes Twice?

Hypothetical situation:

Let's say you follow the bedding procedure recommended for the pads and rotors that you just installed. Soon afterwards you have a need to take the wheels off, do some more work and then clean the rotors with brake cleaner again. I assume that the brake cleaner will remove any pad material that was transferred during the bedding process.

What happens when you go through the bedding process again? Have the pads changed in such a way that they will no longer transfer material like they did the first time? Is it worth the trouble to bed them again?

Just curious...

Reply to
DerbyDad03
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Here is an excellent how to for bedding brakes and an answer to your question.

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Reply to
Gordon Shumway

rotors that you just

me more work and then

er will remove any pad

s changed in such a

ime? Is it worth the trouble to bed

Nothing personal, but I'm not sure that that is an "excellent how to".

As far as I know, there is no one size fits all bedding procedure. Different manufacturers have their own procedure that they want you to follow. I've installed 2 different brands of rotors and pads recently and they both had different bedding procedures.

Some examples can be found here:

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stoptech.com says this:

"Because the adherent temperature range for brake pads varies widely (typically 100°F-600°F for street pads and 600°F-1400°F for race pa ds), each bed-in needs to be application-specific. One could try to generate a one-size-fits-all procedure, but too little heat during bed-in keeps the material from transferring to the rotor face while overheating the system can generate uneven pad deposits due to the material breaking down and splotching (that's a technical term) on to the rotor face."

The zeckhausen site does however seem to indicate that going through the bedding process more than once is a good thing, so thank you for that.

In the case of my hypothetical situation, I would have to assume that if the rotors were cleaned after the initial bedding, then the brakes should be bedded in *two* more times to ensure proper transfer.

Reply to
DerbyDad03

Never "bedded" brakes. Done many brake jobs over the years, and the brakes lasted for years each time. If the rotors are grooved, I replace them too. This sounds like the agonizing over the "hygroscopic nature" of brake fluid. I never changed my brake fluid either.

Reply to
Vic Smith

I never get rotors turned, for a variety of reasons. The primary reason is a new one costs 20-40 bucks. Chevy. I do the brakes myself.

Reply to
Vic Smith

Rotors on new cars are so light, there is nothing to turn. Just replace them. My brakes last at least 110K mils or so. Only needs one brake job before I replace the car. If rotor is over torqued it wraps so easy these days.

Reply to
Tony Hwang

I never knew it was a formal procedure either. I do know when I change pads on a bike I don't plan on doing any 60 to 0 tests for a few days.

I have one bike that uses DOT 5, the 'hydrophobic' stuff. Other than not stripping paint it sucks, but I'm too lazy to do all the flushing needed to go back to DOT 4.

Reply to
rbowman

And never kept the vuhicle long enough to havr the calipers or cyls sieze or leak due to corrosion? It WILL happen eventually if the fluid is not changed.

Reply to
clare

At the cost of most rotors, and the labor rate at most shops, it doesn't make financial sense to turn grooved rotors - particularly since when turned close to the limit they are more likely to warp because they can't hold enough heat (btus) without overheating and can't shed the heat fast enough.

Reply to
clare

Well, it hasn't happened to me. My current cars are 22 and 13 years old. Previous cars were a similar age. Hell, it's not even on the maintenance schedule for my Chevy.

Reply to
Vic Smith

I've never changed brake fluid either. No unusual component failures here. In 40 years, had one master cylinder go and that was on a Fiat that was only a couple years old. Nuff said. At least one caliper would go on that car almost every winter too. Not because of the fluid, but because Fiats were crap and couldn't take any road salt. Don't know of any friends or family that change brake fluid either and no problems there either. IMO caliper failures are from salt and corrosion, not the fluid. Evidence of that is that they typically fail after new pads are put on and the outter part of the piston, which has been out of caliper housing is pitted, corroded etc. The part inside, behind the seal, in the fluid is fine.

Reply to
trader_4

As a mechanic I can tell you I've done a lot of brake jobs on older cars where there was significant rust and corrosion in the cyls.

However, that's not the only issue. Water in brake fluid boils at a lower temoerature than the brake fluid - causing brake fade under hard braking. - another reason to change fluid every 5 years or so, Newer vehicles seal the master cyl against air and moisture intrusion a whole lot better than older ones too - - -

Reply to
clare

I remember honing the cylinders to clean them up. I might even have a brake cylinder hone around some place next to the dwell meter and timing light.

I did have to rebuild the front master cylinder on the Harley last year, but there was no corrosion after 17 years, just tired seals.

Reply to
rbowman

No longer capable to be circus seals?

Reply to
Stormin Mormon

Yeah, they wouldn't work for fish anymore. Losing the front brake reminded me of the bad old days when the Harley front brake was a cable operated drum brake. You didn't have to worry about hydraulic failure. Mostly you didn't use it anyway since it had all the stopping power of dragging your feet.

Reply to
rbowman

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