brake pedal goes to the floor after changing pads

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brake pedal goes to the floor after changing pads

Postby l1ttle_d3vil » Sun Mar 03, 2013 6:16 pm

hey guys, changing the front brake pads in my 1998 Toyota Regius and now the brake pedal virtually goes straight to the floor. Done a bit of searching on the net and found every suggestion under the sun, from bleeding the brakes, twisted brake line, to adjusting the rear handbrake and the brake booster is stuffed.
It is a Toyota Regius with ABS, everything was fine prior to this, just a routine change as they were getting a bit worn.

To drive, it doesn't feel like the front brakes are doing anything at all.
If I stomp on the pedal it will be firm-ish then slowly move to the floor.
If I pump the pedal it will be nice and hard, but once I hold my foot on it, it will go to the floor.
If I jack it up and get someone to stand on the pedal, I can just turn the front wheel, so they are doing something, just not much!

I changed the pads as usual, pushed the piston back in on each side to get the clearance needed, and refitted the pads. Some people have suggested pushing the piston back in can force the seals in the master cylinder to pop inside out and end up leaking...? True?
Others have suggested doing this on an ABS vehicle can cause an issue with the ABS, so you need to crack open the bleed nipple and remove the cap on the m/c before pushing the piston back in.
Someone else has said they ended up with air in their ABS resiovoir and had to bleed this before it fixed the problem.

Is there any truth to this stuff, or any ideas on what to check / do next?

Thanks
-Matt
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Postby Crucible » Sun Mar 03, 2013 7:42 pm

It does pay to crack nipple so you are not pushing fluid back into the abs actuator, I never bother and do alot of brake pads, never had a problem. Master cylinder seals...maybe but again not a common case, ive never had that prob to date. Fluid will bleed back into resevoir through ports infront of seals normally.

I would suggest pulling the front wheels off and check your work. Twisted brake hose yes, if you havent chamfered the pads and the rotors are worn with outer lips it will give you a soft pedal as the pads will not sit flat against the rotors.

You can always clamp hoses and try pedal, take one off at a time to see which side is the problem.
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Postby l1ttle_d3vil » Sun Mar 03, 2013 8:00 pm

Crucible wrote:It does pay to crack nipple so you are not pushing fluid back into the abs actuator, I never bother and do alot of brake pads, never had a problem. Master cylinder seals...maybe but again not a common case, ive never had that prob to date. Fluid will bleed back into resevoir through ports infront of seals normally.

I would suggest pulling the front wheels off and check your work. Twisted brake hose yes, if you havent chamfered the pads and the rotors are worn with outer lips it will give you a soft pedal as the pads will not sit flat against the rotors.

You can always clamp hoses and try pedal, take one off at a time to see which side is the problem.


Aah, always a simple solution you never think of yourself! :roll: Just clamped the brakes off and its the LH side causing the issue. Hoses aren't twisted, will pull the wheel off and recheck everything.
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Postby Grrrrrrr! » Sun Mar 03, 2013 8:05 pm

Also a vote for the opening of the bleed nipple when pushing the pistons back, chances are the fluid has been in there since the pads were put in, so it's full of absorbed moisture and general gunk, so pushing it back thru the rest of the brake system just seems stupid.
Reality: A nasty hallucination that is caused by excess blood in the alcohol stream.
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Postby l1ttle_d3vil » Sun Mar 03, 2013 8:50 pm

Sorted! One pad had slipped back so one of the locator lugs on the side had slipped behind the caliper... if that makes sense :lol: clearly not paying enough attention when reassembling them!
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Postby jr007 » Mon Mar 04, 2013 6:16 am

Meh, they're only brakes, don't pay too much attention 8O
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