Any generic tips on brake pad R&R?

Terry · Post by **Terry** » Tue May 29, 2007 2:13 am

Is there any trick to getting the pistons to draw back in enough to get new brake pads on? Replaced the rear pads on the Hayabusa the other day and had a helluva time getting the pads on. With six piston front calipers, I'd like to know if they're any tips before I give them a try. On the Hondas, its never been too much trouble to push the piston back in to accomodate thicker pads but with this new bike, I don't want to get stuck. As usual, in the manual it pretty much just says remove the pads and reinstall.

alimey4u2 · Post by **alimey4u2** » Tue May 29, 2007 4:13 am

I think the first thing to check, is the reservoir being overfilled on full retraction, as it could become hydraulically locked. Compensator port free & clear ??

cbxtacy · Post by **cbxtacy** » Tue May 29, 2007 10:08 am

On multiple piston calipers I remove the reservoir cap to make sure it doesn't overflow and then remove a caliper, use a screw driver between the old pads and twist it to push the pads apart while checking to make sure I don't overflow the master cylinder and the new pads usually plop right in after removing the old one's. Don't use the screw driver with the new pads because it can gouge chunks out of the pads.

Terry · Post by **Terry** » Tue May 29, 2007 11:57 am

Well, I've never removed the reservoir cap. If I did, would it reduce the pressure against the pistons? Is that the trick?

alimey4u2 · Post by **alimey4u2** » Tue May 29, 2007 12:12 pm

Terry wrote:Well, I've never removed the reservoir cap. If I did, would it reduce the pressure against the pistons? Is that the trick?

There is a rubber bellows inside the master reservoir to keep nasty atmospheric contaminants away from hygroscopic brake fluids. You "may" have a situation where you have topped up the system with fluid due to normal pad wear. When you now displace that fluid back to the reservoir ( compressing the pistons in) it "may" be getting hydraulically locked. IE No place for it to go, therefore restricting piston (brake puck) travel.....

Chris · Post by **Chris** » Tue May 29, 2007 5:12 pm

I've put a bunch of pads on through the years by using a "one man" bleeder device and cracking the brake bleed open on the caliper while pushing the pads back in at the same time. Takes a little coordination but works.

cbxtacy · Post by **cbxtacy** » Wed May 30, 2007 1:34 am

If you've replaced brake fluid as the pads wear, when you push the pistons back in the fluid has to go somewhere. I remove the cap so I don't build up pressure in the cap making it hard to push in the pistons and to remove some of the fluid if it looks like it's going to overflow.

Terry · Post by **Terry** » Wed May 30, 2007 2:14 am

That sounds like a plan as its never been open since its manufacture in late 05. Maybe I'll remove the reservoir lid and then press s l o w l y until the pistons recede before trying to fit new pads. The pads for these six pot calipers are huge!