Brake Master cylinder trying to bleed?

Tiny
JEFF HERMAN
  • MEMBER
  • 2003 HONDA CRV
  • 2.4L
  • 4 CYL
  • 4WD
  • AUTOMATIC
  • 320,000 MILES
The pedal pressures up but then collapses. When trying to bleed master the rear line bleeds fluid but the front line only does when almost all the way disconnected. Bled all 4 corners and pumped out most of the old dirty fluid. Ran ABS with scanner and only got kickback from 3 solenoids but don't think that would affect bleeding. I thought I saw fluid at the back of the master, but I dried it up and can't get it to leak again. No sign of fluid coming through the firewall and booster vacuum line is dry. I was going to disassemble the master tomorrow and make sure all the ports are open. Do you think the master is junk?
Friday, February 28th, 2025 AT 11:11 PM

5 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,264 POSTS
Yes, it sounds like it, how old is the brake master? Here is the correct way to bleed the new brake master on the bench before installation:

https://www.youtube.com/watch?v=WDxvEQrMkBg

Here is the correct way to install the brake master. Check out the images (below). Please let us know what happens.
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Saturday, March 1st, 2025 AT 12:00 PM
Tiny
JEFF HERMAN
  • MEMBER
  • 468 POSTS
It looks like an aftermarket replacement. I picked up a used working factory unit and I'll be installing it today.
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Saturday, March 1st, 2025 AT 1:36 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,264 POSTS
Okay, that should fix it, let me know how it goes.
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Sunday, March 2nd, 2025 AT 11:39 AM
Tiny
JEFF HERMAN
  • MEMBER
  • 468 POSTS
Brakes are working well with the used Honda master cylinder. On to the next project, lol.
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Sunday, March 2nd, 2025 AT 12:04 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,264 POSTS
Nice work! Use 2CarPros anytime we are here to help.
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Sunday, March 2nd, 2025 AT 12:16 PM

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