ZR8ED

Ok. I am not a total newb to cars, and I am pretty good at troubleshooting, but this even has my mechanic a bit stumped. (at least without spending $ to figure it out)

I have two sets of wheels, one with brand new rubber, the other with older ones, and it does it with both sets.
Wheel alignment done. (didn't help) Wheel align was described as excellent before and after.
New brake flush and fluid. (didn't help)
New struts. (didn't help)

Normal driving no issues. Normal braking, no issues Highway driving no issues.

Heavy braking causes the steering wheel to vibrate. The pedal does not vibrate/pulse, or at least I can't easily feel it.

When the car was safetied a few months ago, the brake pads/rotors all passed inspection, but that doesn't mean they are ok.

I'm at a point where I think I should just buy new front rotors/pads, but that really flys in the face of proper diagnosis by just throwing parts at it to fix it. I hate problem solving this way.. it isn't a cheap method thats for sure.

Any thoughts, or common problems? It is an 86 944 N/A. Rotors and pads are of unknown origin/brand.

The longer I look at this post, it seems more of a rant, as I just spent huge $$$$$ to get the car back in shape, and the thought of telling my wife I need to spend even more outside my yearly car budget makes me cringe a little bit.

Scott

krystar

could be rotors have uneven pad transfer.

take 60grit sandpaper and sand down both sides of each rotor. use brake cleaner to get it nice and clean. and while you're there, make sure yer brakes are bled

drive it to nearest safe area to perform brake pad bed in.
get to 60mph, brake hard (but not enough to engage ABS) down to 10mph
repeat 10 times back to back. u will smell brake fume and brake will get soft
drive around 5 minutes using minimal brake.
then repeat the procedure again for 10times





if that doesn't solve it....might want to check your tires for warped rotor

Funn944

the rotors could be slightly warped, which probably wouldn't show up on a visual inspection. If all else fails have the rotors turned (pain in #%$@#), use new pads, break them in and see where that gets you.

bw993

Rotors are probably warped.

gratian

Yes, could be the rotors....but I have the same problems with new rotors just installed...The procedure shows some measurements when install new rotors, so I have to do installs again

Strike-Force

Sounds like warped rotors like many others have said.

gtroth

I've never done this, but if it were me I'd be thinking of measuring the runout of the rotors with them still mounted on the car, try and rule out pad transfer non-uniformity. And then of course you'll need to find max allowable spec...
Anyone know about this?