Hard braking pulls left

rs911t · 08-16-2003, 12:28 PM

This morning I flushed the brake fluid and replaced pads (Performance Friction 97's). All-in-all braking is much improved. But, when I brake hard the car pulls left and if hard enough the left front wheel locks.

Could this be due to air in the right brake line? If not, other ideas?

Thanks in advance.

ChrisBennet · ChrisBennet's Garage

Corner weights off perhaps? I would think it would pull right if it was locking the left front wheel though.
-Chris

Bones · Bones's Garage

Did you check the state of the disks. If you had uneven disk wear new pads would magnify this. If you can hear a low down 'moaning' sound whilst coasting you may have a sticking caliper. If this doesn't make sense then buy even more litres of fluid and have another bleeding session. It sometime takes ages to get right.

Jim Richards · 08-16-2003, 04:44 PM

When you replaced your pads, how did your calipers look?

Greg, here's an idea...just don't brake! Too bad, it looks like I just missed you at PCA tech. I had to run Lu's car (Dino) home and get ready for today's short fun run and Cruise In car show.

bell · bell's Garage

my carrera did the same thing.....front left would lock up prematurely....
what happened was only one of the pistons in the front right was working (inside one frozen)......
rebuilt the caliper (very simple, but delicate) problem went away and stops twice as fast as before

measure the front disks......if they're close i'd pull the calipers.
did you ever use a motive powerbleeder? makes full brake jobs a 1 man job......and no bubbles

ckelly · 08-16-2003, 08:18 PM

Same here, sticky caliper piston, I noticed A LOT of brake dust on one wheel too. Like Bell, I also rebuilt both calipers, and problem went away.

rs911t · 08-17-2003, 05:05 AM

Thanks for the tips. The calipers looked iffy and I noticed some dragging when spinning the wheel. Sounds like caliper rebuild time...

bell · bell's Garage

don't frown..it's not a hard job

use 101 projects and it'll go smoothly, just be carefull not to rip the dust seals when you're reinstalling them, the air compressor trick with a chunk of wood in the middle of the caliper works great......but watch your fingers

since you'll need to rebleed the system pick up the motive power bleeder, it WILL make rebleeding much easier

there are some tips though to the process, let us know when you start in on it

Quicksilver · 08-17-2003, 05:27 AM

You will find that the problem is on the wheel that doesn't lock. One of the pistons is most likely sticking. There is a very slight chance that a pad could be hanging up. Check the caliper where the pads come in contsct with is to make sure that there isn't any major imperfections that the pads could hang on. (This is really, really unlikely)

Did the old pads wear evenly? Was there any unusual taper wear?

One inexpensive possibility is, when the pistons were retracted you might of cocked one of the pistons in the bore. Make sure you cam turn is a bit. I use a set of HD snap-ring plyers. They also work great when aligning the angle of the piston cutouts.

BTW - There disk brakes should have a little dragging when the wheel spins.

Wayne

rs911t · 08-17-2003, 11:02 AM

Good call, folks. The inside, right piston is stuck. Rebuild time!

bell · bell's Garage

woohoo

glad to help......remember.....watch those fingers if you use compressed air to push out the cylinders, i almost lost a pinky once

jazzbass · 08-17-2003, 02:30 PM

Greg - one of the first things I had to do on my Carrera was rebuild the calipers. I have the tools (including my custom made piston extracter

) and the experience. My car almost always stops now. Let me know if you want some help.

BGCarrera32 · 08-17-2003, 03:23 PM

Quote:

My car almost always stops now.

What? And the times that it doesn't you forgot to...step on the pedal...?

jazzbass · 08-17-2003, 04:15 PM

Quote:

Originally posted by BGCarrera32
What? And the times that it doesn't you forgot to...step on the pedal...?

Just a little joke to instill Greg with confidence in my caliper rebuilding abilites

.

rs911t · 08-17-2003, 04:55 PM

Thanks Chris. I think I'll punt on this opportunity. Need to hav'em done by the weekend, but I'm working in Cambridge all week! Gonna call Intersport in the morning to see if Charlie can do it.

jason2guy · 08-17-2003, 05:05 PM

might as well replace the lines as well. i had an 83 once that kept dragging the pads, couldnt figure it out. rebuilt everything. turns out it was swollen lines restricting flow.