Brake fluid flush, now soft pedal?
 

Went back and bled each brake. Both sides of each caliper. No air, no pedal change, still drops. Resivouir never sucked any air. Moved a ton of fluid through them.

Time to stop by Porsche and have them bleed it or buy the pump style suggested in the other thread?

Thanks. Total bummer. :confused:

Ok, next guess would be a leak at the master cylinder?

No fluid level loss. No drips. Pedal is rock hard with car off on second pump. Does not lose pressure. Turn car on, drops 2/3 way down. Second pump it's reasonable. Third pump tight and stays tight. Let off for a second, drops next push.

For me... And FWIW - I'm new to flushing my brakes with a Motive power bleeder.

My first time (:troll:) I learned a lot. Especially ways in which air can get trapped into the brake system.

I now use the Motive to pressurize the system by itself without filling it with fluid, and then I'm very careful not to let the reservoir get too low. It seems that it can happen quickly.

Sounds like an sir bubble could be causing the foot pedal feedback?

If so it's stuck. I've now got a full bottle of brake fluid through the system, a tall bottle. Excellent pressure when we do the pump & crack bleeder method. Then it drops when the car is started.

Do you have PSM? If so, then there is an "Alternative Brake Bleeding Procedure" that is used to bleed the brakes according to the Bentley manual.
Also, I have a Volvo that exhibited similar symptoms, that turned out to be a bad power brake booster.

<Homer Simpson> Doh!!!</Homer Simpson>

Yes I do. I'll read up when I get to shop.

Wanna bet it says "get out your Durametric....".:(

If this procedure of bleeding can instantly kill the booster, that may be what I did...

Bentley has one additional step, to connect the Porsche System Tester II to the car and select bleed. This engages the recirc pump. Supposed to let that go until no bubbles.

Must have gotten air in there. Cost of having fluid swapped at Porsche will surely have bought a Durametric.

DIYing is fun eh Tim?!:chicken:

Not bleeding the ABS will *not* get air into the system.
I think we're looking at some other problem.
BTW: The brake pedal is always softer when the engine is running

Actually, yes. Mistakes I made:

Didn't wait to buy pump up type bleeder as suggested. Just bought what was on the shelf.
Never did buy Durametric. Will place order later. Hope they do Mac.

Didn't get E brake shoes adjusted right. Tear it back down!

Bently manual covers this all very clearly. Someone said you don't need dura to do this, but you do apparently.

One rotor I had turned too rough. Has to go back. Helped with squeal overall but rears already wore shiney and have a slight squeal. Time for some anti squeal sprays. If they don't work new rotors again to finally fix it.

Never finally ordered ceramic pads.

It never ends. Did an alternator, battery, belt, pads, oil & filter on the Touareg and O2 sensor on the ranger.

Fun stuff!!:D

abs can hold air that got into the system in some other manner, ie if the reservoir was drained down too far in the bleeding process.

True, but my point is that the OP believed that he got air into the system by not engaging the ABS booster pump. And all I am saying that not engaging the ABS will not introduce any air into the system.

Thanks for detailing your experiences Tim. When do you find time to work outside the home? Are the bleeders pointing upwards? Many have switched calipers from side to side and can never seem to get all the air out.

Yes. Nipples up. (Insert joke there).

Self employed. 10+ hour days lately. All day today mowing our rentals. Just finished. Some nights late.

I was very careful to keep res topped off but here I am.

I tell ya, I get no respect. Tried to check my timing and it said I was retarded!

:confused: