Dual piston calipers two pistons per caliper, the top piston is pushing out on both sides but the bottom is not moving on both sides

Tiny
EFFECTPRO
  • MEMBER
  • 2012 SUBARU FORESTER
  • 2.0L
  • 4 CYL
  • 4WD
  • AUTOMATIC
  • 70,000 MILES
Mind that I have replaced the entire caliper on both passenger and driver sides, and bled both starting with the passenger side. This issue I was having with the old calipers and am still having with the new ones. They're not sticking. But only half working. Could it be a hydraulic pump problem? Couldn't be a hose issue because fluid has no problem coming out the bled screw and the brake isn't sticking. So I'm at a point where I think it has to be the pump.
Wednesday, September 4th, 2019 AT 6:48 AM

3 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good morning,

Did you verify the slides for calipers are free and moving easily? Most of the time it is due to the pins seizing in the caliper mount.

Roy
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Wednesday, September 4th, 2019 AT 7:59 AM
Tiny
EFFECTPRO
  • MEMBER
  • 2 POSTS
No, they weren't sticking, but I replaced those. Also since my post I have discovered that It is probably my master cylinder. I had no leaks and nothing was seized up. But I was losing pressure. I have replaced the master cylinder and have more pressure than before. Now today I'll be bleeding all the brake lines. Hopefully this will be the fix I'm looking for.
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Thursday, September 5th, 2019 AT 5:53 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good deal.

Roy
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Thursday, September 5th, 2019 AT 5:55 AM

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