Struggling with brake bleed'n

[Marko911/944]

I've posted more in the last week than I have in the several years I've used the forum. Thanks for your responses. What am I doing wrong in bleeding these brakes? I've replaced the entire rear suspension and drive shaft (coloradodriveshaft.com is A+++) and reconnected the rear brake lines. I've topped of the master, pumped the pedal manually, tried to bleed them as any car (no luck) and have moved onto a hand pump brake bleeder. Still no fluid movement. Should the pedal be depressed to the floor under vacuum? Master cap on or off. Help?

[Marko911/944]

Update- The trick seems to be a better quality pressurized brake bleeder running at 100psi. A little more patience helped as well.

[LanceGT4]

if it was an old british car I would suggest pressing the brake pedal about 1/2 travel when using a pressure bleeder.

it seems like 100 psi is way to high.

I didn't have any troubles on my '99 996 C4 using a pressure bleeder at about 20psi on the gauge..
I plan on doing the '05 Turbo Cayenne this winter.
Please update us with what you find out. I'll post how it goes for me.

thanks


Luck

[dshoe]

When you slowly 'pump' the brake pedal you have to close the bleed screw before letting the pedal back up, otherwise the bleed screw is sucking air back into the lines. Make sure the reservoir is always full, otherwise it will suck air into the system. If you get one person to sit in the car and slowly move the pedal, one person to open and close the bleed screw, and one person to watch the fluid reservoir and add fluid when it starts getting low, the whole thing should take like 20 minutes. See if your wife will modulate the brake pedal, you do the bleed screws, and if you have kids have them (carefully) keep the fluid reservoir full.

[dshoe]

If you want to use a vacuum system you don't have to touch the pedal at all. Just have one person work the vacuum and bleed screws and one person make sure the fluid reservoir never gets low.

[Marko911/944]

100psi seemed high to me as well but that's what the tools maker suggests (not to exceed 120psi). It sure made the process quick, and just one person made it happen. Quick was good after 2 days of screwing around. The pedal is solid and I got to move my project around the garage for the first time since I bought it. I did utilize the wife in the beginning, but our daughter is only 6, and just wants to play in the cargo area of the 955! Thanks everybody, more body/paint pics to follow if anyone wants.

[Travis84]

For anyone who will read this at a later date, the service manual states to bleed the brakes with the pressure no higher than 1.0 bar (about 15psi). I bleed Porsche brakes on a daily basis at this pressure and it works well with no issues. Always bleed the outer bleeder first, then the inner.

[Nostril Cheese]

Travis is correct. Do not exceed 15psi. If you cant get the fluid to purge out, you have other problems.

[Determined]

I use a Power bleeder every time and it works great, I have four catch containers in position and simply follow the order of bleeding. It's a good investment and you can buy different caps for various OEM's. Good luck.

[iamtheari]

Resurrecting an old thread instead of starting a new one, to ask...

How much fluid do you go through bleeding the brakes on the 955? I have a 2004 Cayenne Turbo and I plan to bleed the brakes the next time I have some time, and I want to make sure I have enough fluid on hand for the job. Thanks in advance.

[Travis84]

1 liter will do the trick.

[iamtheari]

Thanks.