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Discussion Starter · #1 ·
I need to replace the rear brake pads but do I need to bleed them also or can I just slip the new pads on?
This would be the first time replacing the pads on my bike.
 

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harm said:
I need to replace the rear brake pads but do I need to bleed them also or can I just slip the new pads on?
This would be the first time replacing the pads on my bike.
No you don't need to re-bleed them but push the pistons back into the caliper with the old pads in place. I use a plastic wedge that comes with Hayes brakes. Once you have done that, put that yellow block that came with the brakes (it has tabs that center it into the caliper slots) into the caliper and squezze the brake till both pistons hit the block. Remove block, put new pads back in, Remount and off you go. It's good to reset pistons every time you put new pads on. Follow caliper alignment to.

Here is the procedure with some piston maintenence:
http://bike.shimano.com/publish/con...wnloadFile.html/04) Brake Reset Procedure.pdf
Here is a similar article using a modified yellow piston block. Do not modify the block for the SLX calipers.
http://bike.shimano.com/publish/con...ownloadFile.html/08) Saint Brake Pro Tune.pdf
 

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No need to bleed, but you'll need to push the pistons back in to the caliper: with the old pads still in place, just push a large screwdriver in between them and slowly push them back until the backplates are against the caliper. The pads can then be replaced. Giving the pistons a clean with brake fluid on a cotton tip will help prevent dirt from being pushed into the caliper seals.
 

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Just to clarify something that Austerlitz said above - DO NOT use brake fluid to clean around the pistons and the seals; this will destroy the seals and, ultimately, the brakes. You need to use mineral oil as that is what the brakes and seals are designed around.
 

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DGB said:
Just to clarify something that Austerlitz said above - DO NOT use brake fluid to clean around the pistons and the seals; this will destroy the seals and, ultimately, the brakes. You need to use mineral oil as that is what the brakes and seals are designed around.
An important clarification. 'Brake fluid' is either mineral oil or DOT, depending on what the system is designed for. For cleaning pistons, use mineral oil for mineral oil-based brakes; DOT for DOT-based brakes. The best thing for both types of brake system is a silicone lube or spray - many people just use brake fluid because that's what they have sitting around.
 

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Speaking about Shimano SLX brakes that the OP is asking about, they use mineral oil. I agree with what you're saying that you must then use mineral oil for these brakes.

The point I'm making is that some people may interpret "brake fluid" as what they put into their car's brake system (DOT) and may think that it can be used with mineral oil based systems (Shimano/Magura).
 

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Discussion Starter · #7 ·
Thanks guys for your help! One more thing, can you adjust the amount of travel on the brake lever when pulling for the brake to be fully compresed?
 

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DGB said:
Just to clarify something that Austerlitz said above - DO NOT use brake fluid to clean around the pistons and the seals; this will destroy the seals and, ultimately, the brakes. You need to use mineral oil as that is what the brakes and seals are designed around.

Personally I wouldn't put ANY kind o brake fluid anywhere near the externals of my calipers. They make brake cleaner specifically for this, cheap and available in a high pressure spray can at any car parts store. Dries with zero residue... one drop of mineral or DOT fluid gets on your pads and they are ruined...
 
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