Poor breaks after new birfs?

Curran

 
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I just threw in some new Longfields in the front for the upcomming weekend at CMCC ( :) ) and now my brakes feel rather week. I can stand on the break pedal with both feet and can't get 'em to lock up.
Any suggestions on what to look for or check? :confused:

Curran
 

Curran

 
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I really didn't mess with the brakes aside from moving them out of the way to get inside the knuckle.
I'm dumbfounded. I've removed the breaks twice previously in the same way with out issue.
 

Curran

 
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If I pump the pedal, there is not much of a difference. You can feel a bit of pressure build up, but it gradualy fades away and doesn't seem to decrease stopping distance. I wonder if I could have jamed a brake piston some how.
 

Curran

 
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And wheel bearings are adjusted within spec (according to my cheapo fish scale) How would that effect stopping distance?
Thanks Dan.
 

cruiserdan

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If the wheel bearings are loose the rotor rocks back and forth, kicking the pads and pistons back in. When you apply the brakes the first "push" has to move the pads back out to contact the rotor but you run out of pedal before it really grabs. Subsequent pumping restores a "normal" pedal until you move out again and knock the pistons back in.
 

Curran

 
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Ahh, that makes sense. But I doubt that that is the problem. The bearings were with in spec. My current best guess is that the rotors got a bit dirty in the quick exchange ( I was out of break cleaner ) and the shoes aren't getting a good bite.
It's geting late and dark. I'll give it a look again tomorrow.
Thanks.
Curran
 

Cruiserdrew

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I was just going to say that you got grease on the rotors. Clean them up really well with brake cleaner and I'll bet you'll be happy. There is no other reason that a birf swap would affect the braking.
 

IdahoDoug

 
 
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I also favor the "jammed piston" scenario if the brake cleaner doesn't change things. You'll need to really wash them down as well as see if you can rinse the pads.

DougM
 
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"I really didn't mess with the brakes aside from moving them out of the way to get inside the knuckle."

I suspect this is your problem, possibly you have introduced air into your brake system via a leaky.....?

Bleed the front brakes, it's cheap, easy, and if I'm wrong, it wouldn't be the first time.
 

IdahoDoug

 
 
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Auk,

That's a SWAG without the S part. No way moving a brake component with the hose attached would cause something to leak/suck air. If a hose/seal were that badly rotted, it would have gushed every drop of brake fluid out a long time ago.

DougM
 
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IdahoDoug said:
Auk,

That's a SWAG without the S part. No way moving a brake component with the hose attached would cause something to leak/suck air. If a hose/seal were that badly rotted, it would have gushed every drop of brake fluid out a long time ago.

DougM
Yes sir
 

Gauge

 
 
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Radd Cruisers said:
My guess is grease on the rotors.

Gets some brake cleaner.

Yea. I agree. I have had this happen to me before as well. Once the grease burns off everything is as good as new. You would be surprised how much a few greasy thumb prints can affect breaking performance.
 
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When you backed teh calipers off the pull it off the rotor did you bleed out through the stem or did you just push back in to the reservoir??
if the brake clean doesnt solve the problem make sure you didnt back some build up in the lines into the master cylinder or into the calipers them selves. a quick bleed will tell you whats going on. if you have pressure at some of the points but not at others chances are a blown seal in the master.
theis a a ling shot guess and the others are probably right on greasy rotors.
 
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