I have a bf 6t, I recently have had the front disc machined/new pads, the shudder went away, around 1000k later, the traction control light is coming on intermittently, and now also intermittenly from my front LHS I experience a noticable shudder, not from braking, it will just begin to shudder on the open road, without braking, it comes momentarily then after a tap on the brakes it will go. the wheel bearing is fine. any ideas folks?

The master cylinder may indeed be the cause of the problem, but if your current rotors are warped you will still get shuuder until you change them.

I'd pop into pedders for their $14 suspension check, get the results and contact Pat (senna_t) at Wholesale Suspension in Penrith, he will tell you whats right and wrong and what may be the cause of your shudder.

Does it start at certain speed then stop after you drop below a certain speed? I had some shudder above 80km/h when I first bought the car and it turned out to be just need a front balance. But I didn't have the traction control light come on. Though it could be coming on because it thinks one of the wheels is acting up - maybe not balanced? I'm not sure how braking would stop it from shuddering and the traction control light from going off though.

I think the shudder at a certain speed is caused by your wheel throwing a weight off- been there. Go see your friendly tyre shop for a balance, and while shes up in the air and has the wheels off...

The t/c light may be a bit of steel filings from the skimming or general disc wear, getting stuck to the wheel speed sensor(a little magnet, easily located by following the wire at the back of your wheel hub assembly) and confusing the abs system. Whip the wheels off, undo the little bolt retaining the sensor, 8mm from memory, and remove sensor. Wipe clean of filings and reinstall.

the brake master cyclinder has been replaced and there has been a improvement in the vibrations but they are still there my last options I can think of are the tyre rod ends or the rotors are simply warpped again im gonna try these options at next service if that fail to fix the problem the car will go up for sale. becomeing to much of a money pit to me

Look for hot spots in disc face as you may not have a run out problem - and hot spots cant be machined out.

Edited 05/02/11 03:04 PM05/02/11 03:04 PM by F1PERFORMANCE

the master cylinder may not be the reason you are feeling brake shudder, although it may have been the initial cause of the problem.

If the MC was causing the brakes to drag, the rotors would have got hot and gone out of round, fixing the MC is fixing the intial problem of the brakes dragging but now you will need to machine the rotors again to get them true..

The boosters in the BA/BF are a common problem for holding brakes on and causing shudder. The first one we had we thought the customer was dreaming as she said the shudder would happen at 100kmh whilst driving along. We drove it for ages and couldnt get it to fault. Took it home one night along the freeway and f*ck me...didnt even touch the brakes but had to pull over the shudder was that bad. When I got home and jacked the car up I found the front brakes were stuck on. Pulled the booster valve out and the brakes released. We have done atleast 10 for the exact same problem and upto now the cars havent returned.

As Ratter said,if you had shudder and they only replaced the master cylinder,the shudder will still be there when you use the brakes.

well from what everyone has said here machining the rotors are my next option will let yous all know if that fixes the problem once and for all hopefully 60,000km of brake shudder since buying it will come to an end.

had the rotors replaced under warranty again today. brakes still shuddering decided ive had enough gonna put the car up for sale and get a jzx100. shame really cause its a dam good looking car just cant afford to waste any more money =(