1

I have AVID Juicy Brake pads, the time has come to replace the front pads. The old pads are very worn. The new ones have lots of "pad" compared to the old ones, of course. I've tried to install the new ones but there is not enough room for them in the caliper.
I've tried pushing the pistons back with a screwdriver (they moved a little), swearing, shouting, pondering over cups of tea and watching You Tube on the subject.

Should I let some brake fluid out to allow the pistons to open more?

4
  • 3
    Pushing the pistons back is the way to do it. It's a slow operation that needs lots of care to avoid damaging the pistons. There are special tools but some soft wedge tool would do the job. Screwdrivers are dangerous!
    – Carel
    Jun 12 '16 at 18:00
  • are you sure you;re swapping like-for-like pads? I mean, the pads are compatible with the callipers aren't they?
    – PeteH
    Jun 12 '16 at 19:12
  • 10
    Put the old pads back in, and push them apart with a screw driver.
    – mattnz
    Jun 12 '16 at 22:30
  • 2
    In my case (not Avid brakes) I have had to remove a little fluid to get new pads in place, but this was because the brake also needed bleeding. As air gets into the system the volume increases. You are trying to compress extra air when you try to pry apart the new (thicker) pads. I'd suggest trying to remove some fluid, but with the assumption you may have to add more back in when you bleed the brakes after doing this.
    – Lee-Man
    Jun 13 '16 at 18:13
1

I think you have to open the bleed port. Beware of spilling, and have a towel with some isopropyl alcohol to wipe it down if it spill.

That guy mentions your brake model and the bleeding port trick.

2
  • I had the same issue and I just fixed it. However dont remove too much oil. It's easier to remove some than adding some. Wipping the excess as you unscrew the bleed port should be sufficient.
    – Nicolas
    Jul 26 at 13:13
  • The guy at my LBS told me it's not a good idea to do that. My brake lever had a similar issue. The problem was in the master cylinder. It was corroded and not doing it job properly.
    – Nicolas
    Aug 13 at 16:53
1

This is a sign that someone has bled your brakes improperly.

When bleeding the brakes, you're supposed to remove the wheel and brake pads, and put a bleed block in. The bleed block will only fit if the pistons are moved back to their original positions with a tool such as rubber-covered cone wrench handle (don't use any metallic tools to do this on ceramic pistons). If the bleeding is done without the bleed block and with worn pads, it will overfill the system with fluid, preventing installation of new unworn pads.

So-called quick "lever bleed", by opening the lever fluid cap, screwing a container of brake fluid on it, and repeatedly activating the lever, is one way to bleed your brakes improperly (unless you remove the wheel and brake pads, and put the bleed block in while doing a lever bleed, but that would be so much work and usually "lever bleed" is done to avoid doing much work).

The other answer explains how to fix this condition.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.