Randomly brake pedal slowly goes to the floor

2006 TOYOTA CAMRY

170,000 MILES • 3.3L • 6 CYL • 2WD • AUTOMATIC

JRENNHACK

MEMBER
3 POSTS

I change rear caliper. Bled brakes and went for a drive. And the brake pedal all of the sudden went straight to the floor. I let off hit it again and it was fine. Then next time it went down slowly to the floor. Basically just randomly works fine then bam doesn't. There is no leaks at all anywhere. No air in the system for sure. Could a collapsed hose cause this or a bad master cylinder? Even though there is no leaks of any kind that's noticeable?

Feb 16, 2020 at 10:14 AM

ASEMASTER6371

✓ASE Certified Mechanic
52,796 POSTS

Good afternoon,

Yes, this sounds like a bad master cylinder.

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder

Common for the symptoms you described.

You will need to replace the cylinder, bench bleed the cylinder and then bleed the lines. If you have ABS, you will need to have a scanner that can allow the ABS unit to be bled or you will not be able to get the air our of the lines.

Roy

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Mar 5, 2021 at 10:50 AM

JRENNHACK

MEMBER
3 POSTS

Okay, guess that's what I'll replace next. Hopefully it solves the issue.

Mar 5, 2021 at 10:50 AM

ASEMASTER6371

✓ASE Certified Mechanic
52,796 POSTS

If you do not have an external leak, it would point directly to the master cylinder.

Roy

Mar 5, 2021 at 10:50 AM

JRENNHACK

MEMBER
3 POSTS

That's what I thought just figured better to ask and be 100% sure. Thank you. Hopefully this will fix the problem.

Mar 5, 2021 at 10:50 AM

ASEMASTER6371

✓ASE Certified Mechanic
52,796 POSTS

You are welcome.

Always glad to help.

Roy

Mar 5, 2021 at 10:50 AM

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