New brakes time

Waiex191 · September 03, 2023, 09:07:00 PM

Take a listen to the noise my right caliper makes when I squeeze the brakes:
https://youtu.be/9d0rIhnQXyU?si=iECI-r3tNhZMEg1g

It was doing that before too. I took my calipers all the way apart again and didn't see anything. Made sure they were clean, and reassembled with plenty of fluid during assembly. I also replaced the copper washers which I skipped last time.

Any ideas on the noise and if it is a clue or not?

Brakes have improved a little bit but still not good.

red · September 04, 2023, 07:16:03 AM

Waiex,

Dis-assemble, clean and lube all of the pivot points on the front brake lever, first.
Keep us posted.

Waiex191 · September 04, 2023, 07:22:07 AM

Quote from: red on September 04, 2023, 07:16:03 AM
Waiex,

Dis-assemble, clean and lube all of the pivot points on the front brake lever, first.
Keep us posted.

I'll do that. The brake lever feels great though, I have been pumping it a lot. When I put a finger on the outside of the right caliper I can feel it as well as hear it.

Waiex191 · September 04, 2023, 11:48:10 AM

I did the bungee the lever to the handle trick overnight. Big improvement, and I've got the bungee back on it. Haven't had a chance to do the pivot yet.

red · September 04, 2023, 03:32:14 PM

Waiex,

The caliper body has to slide left and right, to center itself on the disk. Make sure that the caliper is free to move as it should on the mounts. You may need to remove the brake pads to check this. Do not move the brake lever, and you should be able to re-install the brake pads without much trouble.

If the caliper is not free to move, one pad may remain touching the disk, causing the disk to get HOT (not just warm) and that can cause a brake failure or even a lockup.

Waiex191 · September 04, 2023, 04:02:32 PM

Quote from: red on September 04, 2023, 03:32:14 PM
Waiex,

The caliper body has to slide left and right, to center itself on the disk. Make sure that the caliper is free to move as it should on the mounts. You may need to remove the brake pads to check this. Do not move the brake lever, and you should be able to re-install the brake pads without much trouble.

If the caliper is not free to move, one pad may remain touching the disk, causing the disk to get HOT (not just warm) and that can cause a brake failure or even a lockup.

These are 4 pot calipers that bolt hard to the forks - they don't float like my old Suzuki calipers that only have a piston on one side.

Old Rider · September 04, 2023, 04:23:17 PM

I think that is just the pads slapping into the rotor take a close look and se if they move

Old Rider · September 05, 2023, 02:57:34 AM

Or the pistons slapping into the pad. If it is the piston coppergrease or special brakepad tape on the backside of the pad is a solution.
On my last pad change to High sintered i got a similar sound, but that was when driving in slow speed and it was the pads moving forward inside the caliper and make a clicking sound when brake aplyed .Some more coppergrease stops that .

Waiex191 · September 05, 2023, 07:26:55 AM

I looked last night and didn't see them moving. Pads are on the rotor and they just squeeze.

Waiex191 · September 08, 2023, 02:24:14 PM

I added a bleeder banjo bolt at the MC and also did some reverse bleeding as some have described. No real change, I am going to try rebuilding the MC next. I also have another set of calipers on the way from ebay.

RPM - Robert · September 08, 2023, 09:56:49 PM

There is a secondary super tiny hole in the mc that gets clogged easily. When it's apart you can shine a light up the bore and make sure it is unclogged. I don't know how big the dang thing is but seems like it's 0.0001" you won't be able to get the brakes to bleed if that is clogged.

Waiex191 · September 08, 2023, 10:00:20 PM

Quote from: RPM - Robert on September 08, 2023, 09:56:49 PM
There is a secondary super tiny hole in the mc that gets clogged easily. When it's apart you can shine a light up the bore and make sure it is unclogged. I don't know how big the dang thing is but seems like it's 0.0001" you won't be able to get the brakes to bleed if that is clogged.

Thanks! I'll look for it.

melloncollie · September 10, 2023, 10:54:12 PM

Any luck with your brakes? Earlier you were concerned there was a leak: did you see fluid anywhere it shouldn't be? Is the fluid dropping/lever getting soft overnight? Any blemishes on the pistons that you saw during rebuild that might cause a leak past a seal?

Waiex191 · September 10, 2023, 11:14:38 PM

Quote from: melloncollie on September 10, 2023, 10:54:12 PM
Any luck with your brakes? Earlier you were concerned there was a leak: did you see fluid anywhere it shouldn't be? Is the fluid dropping/lever getting soft overnight? Any blemishes on the pistons that you saw during rebuild that might cause a leak past a seal?

I saw no leaks. There was some corrosion on the part of the piston that pushes the pad, but all outside the seals. Plus it was like that before. This week I'm going to pop off the MC and replace the seals, and look for the tiny hole Robert mentioned.

It's not getting soft overnight, just never getting hard.

Waiex191 · September 16, 2023, 01:59:58 PM

The small hole in the MC seemed clear. There are only two holes unless I missed one. I put new seals in the MC and it seemed a lot better, but now I have a sizeable leak getting past the piston. Very frustrating.

I also found my used MC had a busted brake lever.

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New brakes time