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Discussion Starter · #1 ·
I was told that the factory Hayes metallic pads have a built-in safety feature that causes the pads to stop working long before they wear out in order to prevent metal-to-metal contact...can anyone confirm this?

Reason I ask is that I've noticed significant loss of braking power and the problem does not seem to have gone away after fine-sanding the pads and rubbing alcohol on pad & rotor. I have about 2-3mm of pad material remaining.

Thanks!
 

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never heard of that. have you adjusted out the free stroke so there isnt excessive cable slack that the lever needs to pull? do you rotors have black stuff on them?
 

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It's false as far as I know, unless they've changed the design in the last two years. I've ground the pads down to the metal backing plate without noticing it. I heard the grinding before I lost all of the power.
 

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2-3mm is about as much as a brand new pad.... and your brake is mechanical too so no fluid contamination
 

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El Fuego said:
I was told that the factory Hayes metallic pads have a built-in safety feature that causes the pads to stop working long before they wear out in order to prevent metal-to-metal contact...can anyone confirm this?
It sounds like someone's telling you some porky's.

El Fuego said:
Reason I ask is that I've noticed significant loss of braking power and the problem does not seem to have gone away after fine-sanding the pads and rubbing alcohol on pad & rotor. I have about 2-3mm of pad material remaining.
Have the pads or rotor been contaminated with anything?
Are they new brakes?
Do you know how to adjust them?
 

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I used to set those up fairly often and to get maximum performance I found you should not use the barrel adjuster at the caliper to adjust the outboard pad. That should only be used to take up cable slack. Obviously I cannot see your brakes but if by chance you have the throw of the lever reduced significantly...you will lose power.
 

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Discussion Starter · #7 ·
Thanks for all of you who have chimed in with suggestions. Here's an update using my existing pads:

I fine-sanded the front and rear pads and rubbed alcohol on both rotors and that restored front braking power. However, the rear cannot be locked even if I'm OFF the bike and pulling it along. So, since the fronts were working, I decided to swap the brake pads between front and rear to rule out this being a brake pad issue. After the swap, the fronts continued to work great and the rears did not (so, now I'm thinking this is a rotor issue). I checked the rear cable housing and everything looks good. I checked the rear rotor and it's similar to the front, both in appearance and touch. I even fine-sanded the rear rotor and still cannot lock the rear wheel while OFF the bike and pulling it along.

Can anyone solve this mystery?
 

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Discussion Starter · #9 ·
cobba said:
It sounds like the rear brake needs some adjustments made to it, have a look at the following installation guide:

http://www.hayesdiscbrake.com/pdf/MX-1Install45-15216D4LangEnglish.pdf
I just want to add that the brakes have been on the bike for years and have functioned normally throughout. There was no trauma (like a bad crash or anything like that) that would have caused it to lose power. I noticed the loss of braking power going into some turns while riding one day.

I wonder if it's a caliper issue? Although, visually the caliper looks to be doing its job when depressing the brake lever...
 

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El Fuego said:
visually the caliper looks to be doing its job when depressing the brake lever...
Do you mean that the arm on the caliper moves when you pull the brake lever or that you can see the outside pad push the rotor against the inside pad?

If you can see the pads clamping against the rotor how much lever pull is needed for this to happen?

How much clearance is there between the inside pad and the rotor?

Is there any slack in the brake cable? - Can you pull the brake lever in a bit before the arm on the caliper moves?

El Fuego said:
the brakes have been on the bike for years and have functioned normally throughout.
Over the years how often have you been adjusting them and what adjustments do you do?
 

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Discussion Starter · #11 ·
Update: brakes have been fixed

I spent an hour ago looking at how the lever pulls the cable pulls the caliper pushes the pads in, etc. and this is what I found.

What was happening was that while I was going through all available travel as I squeezed the brake lever, the caliper was not able to move inward enough on the rotor to cause normal stopping pressure. The existing brake pad material was too thin to help squeeze out remaining "space." I tried turning the fixed-pad dial but it made no discernible lateral movement as I turned it clockwise or counter-clockwise--perhaps it is broken. So while my pad material was wearing thin, I was not able to move the fixed pad closer to the rotor to compensate. So, I put in new pads and the problem went away because the thicker pad material did not require the caliper to laterally move as much in order to generate stopping power.

Thanks again for all who chimed in. I understand how difficult it is to diagnose something w/out physically seeing it.
 

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The inner pad adjuster on some MX-1's can be turned out using a 3mm allen key as well as the plastic dial. A plastic cap might need popping of from the middle of the adjuster in order to use the allen key.

The inner pad adjuster can sometimes freeze up if it hasn't been turned for a while or if it gets brake dust and dirt in the threads.

I suggest that you try and free up the inner pad adjuster, it'll make future adjustments a lot easier as pads wear.

I have a set of HMX-1's which are basically the same as the MX-1's but an older version. They were on a second hand bike I bought and the inner pad adjusters were frozen when I got it. My HMX-1's didn't have the option of using a 3mm allen key on the inner pad adjuster. To free up the adjuster I had to pop off the plastic adjuster, spray WD40 around the threaded barrel and make it turn with a pair of pliers. Once I got it turning a bit I flushed water over it as I continually turned the barrel in and out, this cleaned the threads up made it turn very easily. I popped the plastic adjuster back on and I haven't had a problem with the inner pad adjuster since.

mtnbiker72 said:
to get maximum performance I found you should not use the barrel adjuster at the caliper to adjust the outboard pad.
I don't really agree with that statement, but I guess different people like different setups in regards to how much lever you have to pull for the brakes to work.
 

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Discussion Starter · #13 ·
cobba said:
I have a set of HMX-1's which are basically the same as the MX-1's but an older version. They were on a second hand bike I bought and the inner pad adjusters were frozen when I got it. My HMX-1's didn't have the option of using a 3mm allen key on the inner pad adjuster. To free up the adjuster I had to pop off the plastic adjuster, spray WD40 around the threaded barrel and make it turn with a pair of pliers. Once I got it turning a bit I flushed water over it as I continually turned the barrel in and out, this cleaned the threads up made it turn very easily. I popped the plastic adjuster back on and I haven't had a problem with the inner pad adjuster since.
Thanks, cobba. I actually have the older HMX-1, as well. I'll try to pop off the plastic adjuster and use some lubricant in there to see if I can free it up.
 

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If you try to do this on your frame make sure you take off the wheel and remove the pads so no contaminates get on the pads and rotor.
It'll be easier to do if you take the caliper of the frame, if you remove the caliper with the adapter still attached you probably won't need to realign the caliper when reattaching it.

To get the plastic adjuster knob off I used a screwdriver.
To get movement back in the adjuster I used a pair of pliers, I can't remember if they were long nose or standard it was over 3 years ago when I did this and I can't actually remember what part I was gripping with the pliers. Once the plastic adjuster knob is taken off you'll be able to see what parts were under it, how the knob fits on, what part it turns and hopefully you'll work out what to do and maybe fix it.

2 weeks ago I would of been able to have a look at my brakes and work out precisely how I fixed them but the bike is currently about 300 miles away and I probably won't see it for months.
 
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