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Brake Problem - Long Pedal Travel

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  #1  
Old 07-23-2015, 11:45 PM
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Default Brake Problem - Long Pedal Travel

The brakes on my daughter's 2001 Disco II have deteriorated recently. When started and moving down the road the first pedal push goes close to the floor before the brakes engage. On the second pedal pump the brakes come up much closer to normal , but then the cycle repeats next time the pedal,is pushed (after some additional,driving). I bled the brakes from furthest to closest with no real change in the long pedal travel. With engine off, brakes pump up solid and stay there so master cylinder okay? With engine off, pumped up brakes and held them and started the engine, brake pedal moves close to the floor so booster okay? Checked the pads and all are still good thickness. What am I missing? Thanks.
 
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Old 07-24-2015, 05:16 AM
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I'm experiencing the same exact thing. I have been since I bought it about 3 months ago.
And brake fluid remains at a stable level at the max fill line for me.

2001 D2 117k..also green. Maybe it's just the green rovers (;

I take it this is not how the brakes normally should operate so I'm sure someone will give us insight. But boy do the brakes work when you need them: someone cut me of while I was doing 60 mph yesterday as they pulled out from a stop sign only seconds before I reached it. Stopped no problem at all, just barely missing the back of that car. Definitely left some rubber on the road from that one and my boss who lives a quarter mile away heard the squeals from his house haha - but it stopped much sooner than excepted; I thought I was going to hit them.
 
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Old 07-24-2015, 05:31 AM
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Sounds like maybe a caliper is not sliding on the pins correctly. They can get corrosion over time and might need to be removed and cleaned.
 
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Old 07-24-2015, 01:49 PM
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I have same problem on mine(also green), i put the hand while pushing the pedal on brake booster under the dash and i can feel air coming out,so i removed brake booster,ordered another one.put hand under dash and see if you have same problem.There is an o-ring(thats from where leaking air),i was trying to find a new one,but no luck.see pics attached
 
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Last edited by fikus555; 07-24-2015 at 01:54 PM.
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  #5  
Old 07-24-2015, 08:34 PM
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Originally Posted by fikus555
I have same problem on mine(also green), i put the hand while pushing the pedal on brake booster under the dash and i can feel air coming out,so i removed brake booster,ordered another one.put hand under dash and see if you have same problem.There is an o-ring(thats from where leaking air),i was trying to find a new one,but no luck.see pics attached
Must be a green rover problem haha

But the new brake booster did fix the problem??
 
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Old 07-24-2015, 10:38 PM
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Sure looking like it might be a "green" thing!

I did take each caliper off a couple of months ago and cleaned them all up. At that time, they did seem to be binding/seizing up on a couple of wheels. Seems like that would make the pedal harder, not longer travel? Might need to take another close look at the calipers and pads. Will check for air from the booster too. Thanks!
 

Last edited by RandyH1221GJ; 07-25-2015 at 02:32 AM.
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Old 07-25-2015, 07:24 AM
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The way the calipers work is, the piston that applies the pad against the rotor pushes out, the pad on the opposite side (without a piston behind it ) will come into contact before there is enough pressure to apply the brakes since it is easier to slide the caliper than apply the brake. Once there is enough force to apply the brake on both sides, the brake pads tighten on the caliper to squeeze the caliper between the pads.

If the caliper doesn't slide so the outside pad comes into contact, you will have to push harder on the pedal, and get a longer pedal travel. Once you let up on the pedal, the pressure on the pads lets up and they stop squeezing the rotor.

Another possibility is that your rotors are warped and once released, the warped rotors are moving the pads farther apart which will also cause a longer pedal movement. This will also cause the pedal to pulsate which you should be able to feel with your foot.

A very basic description of a disc brake setup. there are different variations but similar setups

If you don't feel the pedal vibrate or pulse when stopping, go with the caliper hanging up scenario. I have had to scrape down the sliding surfaces to get them clean enough to work on some cars. If you want to use a lubricant on them, only use lubricant specifically rated for brakes as there are higher temperatures on brake parts and you don't want grease on the stopping surfaces. (they won't stop with grease/oil on them)
 
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Old 07-25-2015, 07:29 AM
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Yup I've got that pulsating feeling each time I brake. Probably new disks and pads will solve it then?
 
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Old 07-25-2015, 12:04 PM
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Originally Posted by Andrew0
Must be a green rover problem haha

But the new brake booster did fix the problem??
Booster arriving on Tuesday, so Wednesday i will know :-)
 
  #10  
Old 07-25-2015, 01:33 PM
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It could be one of many causes:
  1. Defective master cylinder.
  2. Brake servo booster kaput or vacuum incomplete.
  3. ABS or brake system has air in it particularly if anything has been changed and the fluid level has dropped below minimum.
  4. Brake calipers malfunctioning or slide pins seized.

IMO there are so many factors that can cause soft brakes or a long pedal it's an arduous illimination process.

It might pay to acquire a good quality code reader and check the codes. Cheap code readers don't have braking system availability.
 


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