brake bias, rear juddering!

[atokley]

I have a xe nova with a 288mm front brake setup and a rear disk conversion, I've fitted a wilwood bias in the rear brake lines but it doesnt seem to be helping much! The car will lock up the rears only a tad after the fronts! any idea how i can sort this apart from converting to rear drums! lol

Also during heavy braking from around 70mph+ the back wheels vibrate up and down like mad (shakes the car to bits) Is this to do with the brake bias slightly locking the rears and making it hop? (the car has all the powerflex bushes they make for the nova but one of the spax dampers at the rear has started to leak slightly).

Need to sort this braking issue becuase im going to donnington in easter and dont fancy ending up in the gravel lol.

Cheers!

[tom reid]

In line bias valves won't do, you'll need to reduce the surface contact area of the pads, IE cut/grind some material off the pads.
You could look at getting smaller rear calipers.
Are your rear wheels balanced?, change the shockers.
Don't change the rear brakes if you want some fun, just learn to look out the rear window lol

[draper]

theres a vauxhall bias valve that helps this iirc, normally found on nova vans aswell iirc, try the search function / im sure burgo knows iirc (again lol)

[atokley]

In line bias valves won't do, you'll need to reduce the surface contact area of the pads, IE cut/grind some material off the pads.
You could look at getting smaller rear calipers.
Are your rear wheels balanced?, change the shockers.
Don't change the rear brakes if you want some fun, just learn to look out the rear window lol

Rear wheels are balanced, may well be just down to shagged dampers.
Think i may get a new set of pads tomorrow and get my angle grinder out then! lol thanks mate

[atokley]

theres a vauxhall bias valve that helps this iirc, normally found on nova vans aswell iirc, try the search function / im sure burgo knows iirc (again lol)

I will give that a search, thanks mate

[Stuart]

the tramping sounds like a combination of shagged dampers and locking brakes.

about 99% of people with rear discs have these problems, and those who go on track tend to sack off the discs in favor of drums as its not all about show lol

[Will F]

Agreed, but my disks work fine.

I have a pedal box though.....

Dont listed to that crap about cutting your pads down??!! WTF is all that about?

If the rears are locking up AFTER the fronts, then you are fine.

[tom reid]

[quote=Will F]Agreed, but my disks work fine.

I have a pedal box though.....

Dont listed to that crap about cutting your pads down??!! WTF is all that about?

If you don't understand, I'm not going to explain, as you say you have a pedal box, hence you know everything that is related/associated with rear disks!

[Jon_nova1]

i think he means they'll be less surface area, so there will be less judder and less braking force on the back?

[R1CH]

I had probs with the back end locking on mine, already had a Tilton Bias Valve fitted, bought some cheap ass pads & chopped about 2/3's of the material off leaving just a section in the middle, made a huge differnce, cheap set of pads are only about ?10 ... worth ago.

Rich