Took car off truck from east coast. Brakes were horrible. 40K miles Manual No track time. Mechanic said they were rusty from sitting with little use for 2 years. Rotors were only 1/16" lip. Pads 20% The car would barely slow on braking.
New rotors and pads. Good stuff. NO DIFFERENCE. I can slam brakes on so hard ABS triggers and the cars comes SLOWLY to a stop. Like it has no grabbing power. Many many Porsches over 45 years but never a problem like this.
Any ideas.
Thanks

 

Something doesnt make sense. On dry pavement on an even, debris-free road, if you slam on the brakes so hard that ABS triggers, and you still arent stopping quickly, then that means the brakes are working well. They are working so well that they have to momentarily disengage, and re-engage, repeatedly, to stop the car from skidding.

Therefore, the brakes are overcoming the grip of the tires.

• What make/model tires are on the car?
• What is the date code?
• What is the width, front and rear?
• What tire pressure are you running?

 

Air in the lines? Stuck/seized caliper piston?

I would definitely do a full brake flush. I am assuming all pistons are moving too since you already swapped in new brake pads and had to push them in . Also check the brake Master cylinder too! keep us posted. hope you find a solution.

 

Yer right Halo
Something doesn't make sense. Here is more info
Very dry P Zero tires with good tread 80%
6 years old (yeh I know but it has nothing to do with this issue)
19 Lobster Forks with standard issue tires
3K miles on car in last 4 years by PO
I literally pushed on the brakes as hard as I could. ABS just barely triggered
The brakes are waaay too un-grabby to make tires work
I'm not a novice here. I've owned 50 plus 911's 7 Turbos
I've raced several years 944 and Spec Miata
When I jumped into the car with zero miles on the rotors and pads to bed the brakes I couldn't believe the lack of friction down there
THIS IS NOT A TIRE ISSUE TRUST ME ON THAT
It was exhibiting the same issue before new brakes. So that rules out pads and rotors as well.
Someone here must know what is going on.

 

The mechanic has been Porsche indie for 40 years. I can't imagine he didn't flush. He is off racing this weekend so I can't ask but it seems like I'm pumping straight air. I'll try calipers but even if only one of four was working there would be some grab.
Thanks for input from y'all

 

Flush the fluid

 

I'm voting for one or more seized caliper pistons. If the car sat it's possible they seized in place. Now when stepping on the brake pedal only some of the pistons move inwards pressing the pad against the rotor. The effect is a stiff brake pedal but reduced braking power.

 

I'm in this camp as well. Also a spongey pedal definitely mean flush the fluid.

It's also not helping that your tires are old and probably hard as rocks.

Last one, try bedding the brakes after the flush.

 

Calipers are def. working.
Pedal is not spongy in the least. And the pedal is high and firm as in new brakes
There is something else in play here. I'm going to flush it tomorrow but I think that will not be the issue. I'm pretty sure he has flushed it anyway.

 

tires spinning on the front wheels ?
Bonding between front tire and wheel broke ?

EDIT: on second thought, it should be obvious if this is the case cause you will lose air

 

How firm is the pedal?? Does it feel like a block of wood and unassisted? Mine did this and is was a split in the vacuum pipe from the tandem pump which meant the brakes were no longer assisted. You had to stand hard on them for them to work but even then the car did not slow down very well. Check the vacuum pipe.

 

Oh, good one. Can I change my vote to vacuum assist not working?

 

I thought I would circle back as a courtesy to those that spoke up. And the winner is
....
Krispe Kreame. It was a vacuum issue!

 

WHOO HOO Do I get a prize? It's not often I know the answer to a Porsche problem. I found one of the benefits of Porsche ownership is the amount of knowledge available on the forums from other Porsche enthusiasts.

 

Free Krispe K's for life at any Starbucks.