Cleaning up a rear brake caliper

[Sandblaster]

First and foremost.... Ignore every thing I say.
I am not a professional mechanic, I have no training, and generally I ride stuff that is completely unsafe and I do things that should never be done.
I just thought you might appreciate a emergency brake clean up.
I recommend that you get a service manual and follow the instructions to the letter.

A buddy of mine has to go riding tomorrow and of course he waits until today to bring me his brake.
I have no pads or seals to rebuild this rear brake caliper.
Therefore I will do the best I can with what I have to work with.
In the mean time I have ordered him caliper and master cylinder rebuild kits and new pads....
To start with we have to start disassembling this mess.
It's best to clean your brake BEFORE you start but whatever I'm in a hurry and I'll do it wrong anyway..

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To do what I want I have to disconnect the brake hose.

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When you disconnect the brake line you open up a direct path to the inside so I plug the hole with a bolt so I can continue cleaning without contaminating the insides.

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[Sandblaster]

Next I removed the caliper mount.
This style is easy, just pull them apart.

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After removing the mount I removed the two pad pins... What a mess...

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I removed the bolt that is in the hose mount because I need to blow compressed air down that hole to remove the piston.
What a mess...

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[Sandblaster]

When using compressed air to move the piston I like to use a shop rag to make a barrier to keep the piston from shooting across the room.
Yes, they will shoot across the room

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Put your rubber tipped nozzle in the brake hose hole and give short bursts of air.

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Typically they will shoot out with a noticeable pop..
If you don't use a rag to keep the piston from shooting out, be sure to aim it in a safe direction because the piston will easily shoot out 12 or more feet even under fairly low air pressure.
This one oozed out because the piston and seals were completely gummed up.

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[Sandblaster]

Disgusting.

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I clean the bleeder valve with a guitar string.

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[Sandblaster]

I make sure that the guitar string can go all the way in with no obstructions.

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Whatever it takes... get it clean.

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Ooooohhhh Purdy...

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[Sandblaster]

If I had my way I would replace the seals, pads, and pad pins.... but... I don't have replacements so he is gonna get what I give him and like it...

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Again, I clean everything..

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[Sandblaster]

Assembled.

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Because the pads are wide open I give the caliper a quick shot of air down the hose hole and they snap shut.
If yours is slow to close, better give it a complete rebuild...

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Half done...

[Roostius_Maximus]

Aren't you supposed to hold that caliper with your fingers in the pad location and nails towards the piston before using the blow gun?



seen it happen

[Sandblaster]

If you do, please take pictures...

[Sandblaster]

I ordered some rebuild kits so I will do some complete rebuilds for the front master and the calipers...