Need help with front brake issue
 

Background; Boxster brakes front & rear, new pads, new fluid, new lines, recent alignment/corner balance.

Under hard braking, car pulls right and right front wheel will lock before the left. Kind of un-nerving to say the least.

Brakes have been bled, fluid topped off, swapped pads from side to side.

Anything else to look at? I do not think calipers need a rebuild, but if that will help, I'll do it....

TIA!
-B

Considering you have new lines, how many miles are on the calipers? Under their previous owner, was the fluid changed often. Sounds like you need a rebuild.

The only time I had a car do that ('72), one of the front caliper pistons was sticking. Check it out.

Uneven front castor can cause the pulling problem under braking. Even though the car has been corner balanced, I'd expect that with you in the driver's seat the right front wheel will carry less weight than the left front. If it's a significant difference, that might be the cause of your problem.

JR

Corner balance may mean a few different tings...and this may impact the issue, too.

"True" corner balance apportions each corner he appropriate weight it "should" carry..based on the distribution of the various masses within the car ( battery, engine, etc). So...a true corner balance might have one of the front two wheels carry a different load. On threshold braking....this would make one wheel lock up sooner than another.

If this weight difference is severe, then it might be a better trade-off to lose a bit of corner balance goodness....and force a bit of "weight-jacking" on the car...so that the front two wheels carry an identical amount of weight. This compromise setting would help heavy braking but the CB would be "off" by a bit....

My latest thinking about corner balance trends me in this direction anyway...to get the front wheels even. There was a long thread involving me, Craig911, and Randy Blaylock where I got the "new religion"....

Consider this after you check the stiction or rebuild needs of the various calipers.

- Wil

Thanks for the replies. The car is pretty darty at high speeds and I think the caster may be affecting that, so it could be contributing to the braking issue as well. I'll do a rebuild of the calipers and will go from there. Wil, do you have the link to that thread you reference?

cheers
-Brad