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Discussion Starter · #1 ·
I just installed new Pagid Oranges on my 06 CS and got done bleeding the brakes for the second time. I use a pressure bleeder to flush the fluid, the finish by pumping. The pedal feels like a rock....until I turn on the ignition...then it is soft enough it goes just about to the floor. If I pump with the ignition on, it gets progressively harder, but as soon as I keep my foot on it, it slowly makes it way to the floor. There are NO leaks, and I have re-bled twice....anyone have any ideas?

I can't take it out and drive it because we have about 5 ft of snow on the ground! Has anyone noticed this before, and does it cure itself after bedding the pads? TIA
 

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Discussion Starter · #2 ·
any thoughts...???? No one who has changed pads experienced this?

I remember in our Audi's I had to VAG the car after bleeding the brakes in order to get the vacuum assist to re-pressurize or something. However, we never had to do this with our Cayenne or 911's...so I'm at a loss.
 

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Two things come to mind.
  1. Sounds like you have some air trapped. There are two differnt levels of bleeding. To achieve level 2, you need a PIWIS to activate the ABS actuator, where air can get trapped.
  2. Is this soft pedal when stopped or driving? If when driving, you may have glazed the pads with an incorrect bedding process. It sounds like you haven't driven it yet, so I doubt this is it.
 

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Karrera-
When you say the ignition is on, is the engine running? If so, what you describe sounds normal.

Dave
 

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Sounds like you have some air trapped. There are two differnt levels of bleeding. To achieve level 2, you need a PIWIS to activate the ABS actuator, where air can get trapped.
That was true of the older generation ABS system, but I don't believe it is required on newer Porsches such as our Caymans. Are you sure?
 

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Discussion Starter · #6 ·
Two things come to mind.
  1. Sounds like you have some air trapped. There are two differnt levels of bleeding. To achieve level 2, you need a PIWIS to activate the ABS actuator, where air can get trapped.
  2. Is this soft pedal when stopped or driving? If when driving, you may have glazed the pads with an incorrect bedding process. It sounds like you haven't driven it yet, so I doubt this is it.
I have not driven it yet.

I was worried about your number 1 answer. Is there any way to overcome this? Can I activate it with Durametric? My nearest Porsche Dealership is not about 2 hours away. Is it possible to pump the air out when bedding the pads in and then re-bleeding the brakes? TIA
 

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I'm not sure if this helps, but I've noticed that on both my G35 and Cayman if I happen to have the foot on the brake when I turn the engine on, the pedal will drop a good distance down.

I never worried much about it because once I lift my foot off and press again, it returns to normal position.

The Cayman has the stock factory brakes and pads were never changed. The G35 just had rotors, pads and fluid changed last week and it still behaves the same way. It was like this on the G35 before the brake work also...

I don't know the first thing about brake systems, but isn't there some sort of vacuum assist mechanism that gets primed when the engine is started? Maybe somehow this is causing the pedal to slowly drop.

Now the part about it continuing to drop after the engine is on, I'm not sure about. I won't get a chance to sit in the cars again until this weekend, I'm sure someone else here can verify the behavior.
 

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Good luck with this issue. I went through a nightmare with my 09 CS. Changed pads and bled the system. Felt ok and then went to Mid-Ohio. After a couple of laps the pedal went to the floor. Came home and went through the system a few more times and then it was off to the dealer. They bled them twice and I still had the soft pedal. Next up they put in a new master cylinder and booster. Same problem. Next they took the system apart and checked dimensions. Bled again and then used the PIWIS. The car is now in the garage. I'll get it out sometime next month before I go back to Mid-Ohio April. Until then I won't know but I think I'll be ok. Porsche of the Village in Cincinnati was great to deal with this the whole way through.

You should be able to get a hard non sinking pedal with the engine off. If you put your foot on the brake and then start the engine the pedal will sink. What should not happen is your foot going to the floor with ABS engaged. That was what happened to me.
 
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