[Lonestar968]

OK all you brake experts, I need your help.

Here's a synopsis of what I did:
1 Installed rebuilt BR calipers and two-piece rotors
2 Installed new 33/5 Pro-valve
3 Installed new Power Bleeders on BR calipers
4 Installed new front brake pads
4 Installed new braided stainless brake lines at all four corers
6 Purchased and used the Motive Power Bleeder w/ ATE fluid
7 Bled all four corners
8 Drove it, ABS activated three times
9 Bled it again
10 Drove it, ABS activated four times
11 Bled it again
12 Drove it, ABS continues to activate under hard braking
13 Parked in garage, cracked open an adult beverage, assumed "Thinking Man" position

Here's the result:
1 Pedal still feels weak/soft
2 Pedal still travels too far
3 Pedal is not crisp or tight
4 ABS pump activates upon hard braking (not locking up wheels)

Help... [img]style_emoticons/<#EMO_DIR#>/huh.gif[/img]

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[flash]

sounds like it's not bled fully - probably stuck in the abs - could be the power bleeders not playing well with the motive - try regular bleed screws

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[RS Barn]

Try a combination of power bleeder at 15 psi and brake pedal pressure (need another human)
This generally results in pueshing any air pockets out and a high firm pedal
Pete

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[Lonestar968]

Thanks guys, I'll try both.

Pete, aren't you up kinda' late? It's a school night you know!?

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[pure&amp;simple]

I've had a similar problem. The manual + pressure bleed method does help, but I wonder... is there a way to cycle the ABS while you are bleeding? Is that something that the Bosch Hammer can do?

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[Lonestar968]

Good question. I've only read about it here on the forum, I have no personal experience with it at all. What CAN a Bosch Hammer actually do???

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[bob blackwell]

As far as I know the Bosch Hammer reads codes and resets warnings. It just plugs into the on board diagnostics plug to assist in determining problems. Dan, if you don't have a blockage in your hard lines or internal swelling in the rubber lines that are still on your car, the manual pedal pushing plus power bleeding should do the trick to bleed all of the air out. Good luck, Bob Blackwell.

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[banditsc]

On the 993 you need to the Bosch hammer to cycle the ABS to properly bleed the brakes. But with the ABS being engaged like it was, should have been enough to push the bubbles past the ABS controller. I'd guess it just needs a good bleeding now.

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[savvas968]

Seems that LR have a write up on the installation of the Big red when installed.

They need to change the connecting pipe and bleeders the other way around to get the

differential piston diameter the correct direction,as the big reds are mounted on the 911

in front of the disc.

You might want to check it out.

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[savvas968]

Just some experience i had with same issue,.It is possiple as i found out that the front in now overbraked with the existing tires .

When the big reds were fixed ,when applied the brakes ,due to the bigger force,the fronts go to lock up and the ABS is activated to compensate

installing wider tires or softer compound seems to elliminate this issue.Hope it helps.

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[flash]

yup - it's amazing how hard it is to convince people that big reds up front, without doing them in the rear, is a mistake, and requires rework to reacquire braking balance

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