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Writer/Teacher
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sigh... brake issue revisited
Well, I changed my front brakes to Axxis Metal Masters. The braking is much better, but there is still WAY too much travel in the pedal before the brakes actually bite. I know this is true because I drove MikeCT's car right after mine and his braked better even with old pads. Much better.
I wouldn't say the pedal feels "spongy," but rather that there is a lot of travel before you feel anything that is even remotely firm. According to the Haynes manual, this can mean either air in the system or a partial brake system failure. Any thoughts?
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Current Stable: Black 07 Porsche 987 Cayman S: Long-Tube Headers; FabSpeed Exhaust; VividRacing ECU Tune; IPD Plenum; 997GT3 Throttle Body. Blue 1983 Porsche 928S. 1985.5 Porsche 944 Rat Rod. 2011 Acura MDX. 2008 Mazda 3. Gone But Not Forgotten:Garnet Red 86 Porsche 951("The Purple Pig"). Alpine White 83 Porsche 944 ("Alpine Wolf"). Guards Red 84 Porsche 944. |
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10-16-2003, 12:15 PM
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Let's go shooting.
Join Date: Feb 2003
Location: United Kingdom.
Posts: 1,200
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What procedure are you using for bleeding the brakes?
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1983 944 Lux (manual) 2.5 litre 8 valve na and no pas 1991 944 (automatic) 2.7 litre 16 valve na and pas "I have only five words for you: From my cold, dead hands." |
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10-16-2003, 12:19 PM
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Registered
Join Date: Dec 2002
Location: St. Petersburg, Florida
Posts: 1,990
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Just a side note....the $14 speed bleeders from pelican were the easiest /most time saving mod I have ever seen...If I had any "air" questions they would be my next money spent
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83 944 white w/Boxster wheels Planned mods- custom leather interior, 968 antenna, soundsystem, 968 style rockers, clear sidemarkers
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10-16-2003, 03:20 PM
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Sounds like either hydrolic failure (perhaps blown master cylinder on one of the two circuits), or air in the lines. Assuming you've successfully flushed a brake system before, I would think the master cylinder is the culprit.
If you can get a buddy to help out, jack up the car and press on the brake pedal lightly, see if various wheels can be turned. If there's significant difference between rolling ressistance of two wheels on one circuit compared to the other (at the same pedal pressure), you've likely found your problem. Let us know. Ahmet
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Cheers! |
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10-16-2003, 10:24 PM
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Writer/Teacher
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master cylinder was replaced about 120 miles ago. this problem occurred before the replacing of the master cyllinder and has gotten worse since then
on a positive note, the brake pedal seems to be getting firmer the more i drive with it... should i still bleed the system, or maybe wait a few days and see if the pads just need a chance to settle?
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Current Stable: Black 07 Porsche 987 Cayman S: Long-Tube Headers; FabSpeed Exhaust; VividRacing ECU Tune; IPD Plenum; 997GT3 Throttle Body. Blue 1983 Porsche 928S. 1985.5 Porsche 944 Rat Rod. 2011 Acura MDX. 2008 Mazda 3. Gone But Not Forgotten:Garnet Red 86 Porsche 951("The Purple Pig"). Alpine White 83 Porsche 944 ("Alpine Wolf"). Guards Red 84 Porsche 944. |
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10-17-2003, 12:17 AM
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Moderator
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You're certain you bled the system properly? Now it sounds like air in the lines, but then again you said the pedal wasn't "spongy"... Try to look at it ASAP.
Ahmet
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Cheers! |
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10-17-2003, 12:25 AM
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Registered
Join Date: Feb 2001
Location: Viera FL
Posts: 5,642
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Pads do need a day to two to "settle", but no more than that. the pedal should still be stiff on a freshly bled system.
Rebleed your system - either by pressure or vacuum - either way works fine, you just need to teflon the threads of the bleeders and the connections of the vacuum bleeder to make sure you don't let air in. Test your brake booster (pump up till stiff, then start the car, the pedal should drop slightly) Check all vacuum lines to the booster. Also check the condition of your brake hoses. Worn brake lines can give you a spongy feel. AFJuvat
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Es geht nicht darum wie schnell man faehrt, sondern wie gut man schnell fahren kann. Ihr Brunnen der nutzlosen Porsche Information |
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10-17-2003, 05:43 AM
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Writer/Teacher
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When I test the brake booster:
I pump up the brakes until they are hard as a rock (about 4 pumps or so) and then start the car... the pedal goes way down as soon as my foot touches it. Sounds like brake booster is ok? I think I might just need to rebleed system.
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Current Stable: Black 07 Porsche 987 Cayman S: Long-Tube Headers; FabSpeed Exhaust; VividRacing ECU Tune; IPD Plenum; 997GT3 Throttle Body. Blue 1983 Porsche 928S. 1985.5 Porsche 944 Rat Rod. 2011 Acura MDX. 2008 Mazda 3. Gone But Not Forgotten:Garnet Red 86 Porsche 951("The Purple Pig"). Alpine White 83 Porsche 944 ("Alpine Wolf"). Guards Red 84 Porsche 944. |
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10-17-2003, 08:11 AM
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Writer/Teacher
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ok... every time I drive the car, the brake pedal gets a stiffer; there is a lot less travel now than there was right after I did the brake job. should I assume that all is well?
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Current Stable: Black 07 Porsche 987 Cayman S: Long-Tube Headers; FabSpeed Exhaust; VividRacing ECU Tune; IPD Plenum; 997GT3 Throttle Body. Blue 1983 Porsche 928S. 1985.5 Porsche 944 Rat Rod. 2011 Acura MDX. 2008 Mazda 3. Gone But Not Forgotten:Garnet Red 86 Porsche 951("The Purple Pig"). Alpine White 83 Porsche 944 ("Alpine Wolf"). Guards Red 84 Porsche 944. |
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10-17-2003, 09:32 PM
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Registered
Join Date: Feb 2001
Location: Viera FL
Posts: 5,642
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Rebleed the brakes.
AFJuvat
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Es geht nicht darum wie schnell man faehrt, sondern wie gut man schnell fahren kann. Ihr Brunnen der nutzlosen Porsche Information |
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10-17-2003, 09:48 PM
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Ever jump a Porsche?....
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CJ,
Not sure if you solved your problem or not, but it sounds like you didn't get the pads close to the rotors when you installed them. Your pads are basically too far away from the rotor causing such a long travel of the brake pedal. If that is the case... Your pedal is slowly coming back because each time you apply the brakes the pads don't quite return to where they were before you used them. They are adjusting slowly to where they need to be. Just a thought.
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Casey Road-rally, Targa Newfoundland junkie!!! 1969 RSR 3.4L PCA class GT-3 (in progress)...1800 lbs and dropping Thinking of driving in TARGA NEWFOUNDLAND? Contact me and I can help answer your questions. The event is awesome! |
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10-26-2003, 04:09 PM
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Let's go shooting.
Join Date: Feb 2003
Location: United Kingdom.
Posts: 1,200
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Quote:
Try running the engine, pumping up the brake peddle, then holding it down whilst someone cracks open the bleed screws (bleeder attached obviously) in turn. I've often found that this breaks the air pockets.
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1983 944 Lux (manual) 2.5 litre 8 valve na and no pas 1991 944 (automatic) 2.7 litre 16 valve na and pas "I have only five words for you: From my cold, dead hands." |
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10-26-2003, 04:38 PM
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Writer/Teacher
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I am almost positive that I have air trapped in the system. One day the pedal will be firm with almost no travel, the next day there will be inches of travel before I encounter any firmness. I am going to rebleed the system the next time I get a day off. I predict some time in the early 2020s.
__________________
Current Stable: Black 07 Porsche 987 Cayman S: Long-Tube Headers; FabSpeed Exhaust; VividRacing ECU Tune; IPD Plenum; 997GT3 Throttle Body. Blue 1983 Porsche 928S. 1985.5 Porsche 944 Rat Rod. 2011 Acura MDX. 2008 Mazda 3. Gone But Not Forgotten:Garnet Red 86 Porsche 951("The Purple Pig"). Alpine White 83 Porsche 944 ("Alpine Wolf"). Guards Red 84 Porsche 944. |
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10-27-2003, 08:15 AM
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2007 Porsche Cayman S
The Viridian Falcon
SOLD! -- The Purple Pig
SOLD! -- Mighty Mouse
SOLD!! -- Alpine Wolf
1984 Porsche 944 2.5 liter, 8 valve 
