Brake Pulling - Still chasing it...

widebody911 · widebody911's Garage

I've been chasing a problem with my brakes (930) pulling to the left under moderate to heavy application. It feels like the car is "rotating" and I'm in the habit now of subconciously correcting to the right, which of course causes the car to pitch to the right when I let off the brakes. It does it at high speeds or low speeds, it doesn't seem to matter.

Shocks are just a a few (<6) months old.

Lines (SS) are about 1 year old

I just rebuilt the front calipers tonight. Waiting for Niello Porsche to get their ^%$#@!*^% together and get my seals for the rears

Rotors and pads are new

Alignment was checked 2 weeks ago.

This started just after I installed the new oil cooler and IROC front bumper.

The only thing I haven't checked is corner balance, but I'm skeptical that balance would have that much of an effect on braking.

Any other suggestions?

I have enough seals on hand to do one caliper - should I do the rear on the side that pulls, or the side that's not pulling? (until I get the rest of my seals)

I face Jack next Sunday - my brakes need to be 100%!

Thanks!

beepbeep · 07-01-2002, 12:07 AM

Hi Thom!

Sorry to hear that you still have pulling issue.

Let's do a quick checklist:

- Are calipers OK now? Do you need to apply same amount of force to press them in?

- Are pads free to move when you press the brakes? No Ti-shields or oxidation causing them to get stuck?

- Is wheel geometry OK?

(If you feel that steering wheel is trying to twist itself from your hands when braking then it's a problem with front brakes and not rear, but check piston condition @ rear anyway)

And finnaly: (this is my guess)

- Are master brake cylinder and brake hoses OK??? You might have coroded/pinched brake lines going to one of calipers or MBC is acting up on you. This should be last thing to check...there is nothing more!!

Also, was it hard to rebuild the calipers? Pics on that would be nice :-)

dickster · 07-01-2002, 12:22 AM

all other things being well it may well be the corner balance.

mine had a tendency to lock up the front left. but it also rolled into that corner on right hand bends.

i lifted that front with the adjuster a fair amount to see what difference it made. (took fender measurements first). i now get both front wheels locking together.

the handling problem is still there though not as bad. i am going to pull the torsion bar (didn't know it was so easy!) and check it out.

but you track yours, so whats it handle like, is it better in left bends than right etc??

when i stand at the front of my car and push down on the centre of the bumper i can see uneven movement of the rear of the car, the right side rises higher than the left.

btw-corner balance should be done before alignment!!

good luck.

GeorgeK · 07-01-2002, 01:26 AM

Thom,
This maybe far fetched, but I have seen it in one case already:
Are the calipers the same? Lemme explain... The 930 calipers are made of 4 parts, the 2 "bridges" and the 2 pistons parts.
It is possible to dismantle the calipers and put the pistons parts from the front on the bridges from the rear, meaning you have the big pistons on the rear axle.
I have seen it once on a reconditionned set where the guy mixed the pistons parts and had small pistons from the rear on one front brake, causing interesting braking.
GeorgeK