Cleaning caliper pistons/ Cleaning???

I put new pads on my 400f and now my brakes drag (front). Someone on this board suggested I nedd to clean the pistons. What is the proper method for doing this? I checked to make sure the pads are flat , and they are. I also put my old pads back in and the problem was gone (no more drag).I am assuming that whoever said the pistons are sticking is correct.Whats the next step??

how bad are the pads dragging??? if they only hit a little bit and make a scraping sound it is not a problem. if they actually make the wheel slow down then your calipers need to be cleaned. just remember the only force pulling back the pads is the return of the master cylinder. there is no spring the pads simply rub a bit without applying much pressure. to clean the caliper you must remove all the fluid from the system and dismantle the caliper per the instructions in your service manual. use a good quality brake parts cleaner that wont flashover so that you dont have any happy little fires in your garage. good luck, I have never dismantled the caliper on my WR but on my Buells it is a very simple procedure that only takes a few minutes.



sa dah tay


There are a few reasons why the pads will drag.

First thing, reset them by pushing them back into the caliper slightly. Then pump them back out. If they still drag, you either have sticky pucks or too much fluid in the master cylinder.

The only way to clean the caliper is to remove it from the bike. Compresses air, some small wood or plastic blocks, (and some safety glasses) will allow you to blow out the pucks.

Yamaha recommends replacing the seals at each rebuilt. For the price, I would do it.

Clean things up with brake cleaner followed by compressed air then reassemble.

In some cases, certain high performance brake fluids don't mix well and cause some sticking as well, so you may want to rebuild the whole system if you have been doing this.

Also keep in mind that you'll need to tap the caliper, line and cylinder when ever you refill them (get's the air bubbles out). And of course, park the pucks before you bleed as well.

Be patient and do all you can to consider where the air get's trapped. Goes along way.

Hope this helps.


The above advice is great. I just wanted to second checking your fluid level. Since I neglected to mention that when I posted about the brake caliper.

I'm sure this is a simple problem.

Good Luck,

the fluid level is the first thing to check....damn, I always forget to tell/do that. wonder I always screw stuff up on my bikes. attention to detail, attention to detail, attention to detail.

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