mhhhuang

Ever since, I converted steel front wheel hub to RS aluminum hub. Some strange thing happens. After several hard brakes, the steering starts to vibrate while I apply brake. It will back to normal when the brake cool down.

The brake disk has been checked. No warping. Put a new set of disks still couldn't solve the problem. Wheel bearing has been changed twice. Tightening torques all follow work shop menu.

Does anyone know how to fix this problem?

Geoffrey

What brake pads are you running? What you describe sounds like pad deposits on the rotor from either improperly bedding in the pads, or from using the pads outside of their intended temperature range.

WHITECAR

Yes, like Geoffrey said.. Pagid orange with certain weights/demands are a real mess.....
Pagid Blacks.. problem gone. Just a thought.

mhhhuang

I use Pagid RS15. The problem started after I switched to RS front wheel hub. But not right away as I remember. I never thought about the cause of brake pad. How do I check? How do I fix?

Jeff Curtis

First of all, check the tightness of your wheelhub nut/bolt combo - I doubt this is your issue but it's a start. It's possible your hub was not properly seated in your wheel bearing and it "settled" and is either cocked and ruining the bearing or you have some play in there.

Otherwise, what Geoffrey says...he seems to know EVERYTHING, and a bit more about these 964 thingeys.

mhhhuang

I did. The hub bolt tightening torque is 460 NM. Changed the bearing two times to ensure the bearing was properly seated. Someone suggests me to fit the bearing with the upright completing off the car on a pressing machine. So, there is not doubt the properly bearing seated. I haven't tried that yet.

Thank you all for possible solution.

Michael

Geoffrey

It is nearly impossible to install the wheel bearing or hub incorrectly.

NineMeister

The last time we experienced this problem was on a 964 with a Big Red/Turbo 3.6 disc combination with factory brake pads. The cause was traced to the customer not bedding in the pads correctly - he thought it would be best to "run them in" by using the brakes gently for a few hundred miles. In the end we changed the discs and pads for another new set and then I went out in the car and "killed them" - i.e. got them almost to the point of fade (which is not an easy task on the road!). Following this special treatment the problem never recurred.

This could be the cause of your problems, however.....

mhhhuang

Colin

Thanks. I am your customer in Taiwan. This problem has been hanging there unsolved in my 964 RSA in past one year. Because I put all my attention to your 3.8 kit on my cup car. By the way, your engine kit runs beautifully so far.

Both you and Geoffrey are experts on 964. I will try to bedding my brake again.

Michael

NineMeister

Hey, hello Michael, great to see you enjoying the Rennlist forums, it's a great place to learn for all of us.

Glad to know that the engine is performing as expected, however I was kind of hoping that you were going to pay for my flights to come and help you build it, pop it in the car and map the Motec system, I could do with some sunshine for a change.... maybe next time, eh?

If you do have the disc problem that I mentioned with your discs, you may have to have them machined in order to get fresh metal for the pad to run on. We sent new discs to my customer to speed up the process, his old discs were returned, skimmed and fitted to one of our own cars, after which they worked perfectly. Keep us informed of what you find out.

NineMeister

If this doesn't work, you could always try breaking your bed instead?

demonfish

funny you should say that....

i fitted the big reds to mine, bedded in gently etc etc then when i got to donington, once a little warm they were wobbling all over the place!!!

a few hard laps soon sorted that out though... so is that the trick, new pads and bust their *****?

mhhhuang

Colin

Taiwan has a lot beautiful mountain roads. 964 is fast in our road condition. You can do different kind of autosport. I would love to invite you to come for next engine upgrade project. You carry parts in instead of UPS. I think it may end up cheaper that way.

Mezger

Dear all,

would the standard non RS wheel hubs fit on RS carriers?
Thanks for advice!