brakes

[Jedro]

hello friendly folk of png, i rarely come on here, dont know why as theres alot of canny people. thought id ask some advice on brakes. sorry if its the wrong section, could admin move it if it is please

problem ive got. bought the corsa and the lad who sold it to me didnt know much about the mods that had been done to it before he got it (was a run around to him). said its got gsi callipers, i said "gsi what, corsa astra...?" he said "oh i dina, just gsi ones"
cut a long story short it seems to be warping the discs quite quick, it was fine when i got it then started to warp them (not for of needing replaced anyway) so i replaced them with mintex 256x20 (normal for corsa gsi's/1.6sports) and these new ones have only lasted about 3 month of not really driving it loads.
i know that the 2.0l's use 4mm thicker discs, does it sound like ive got 2.0l callipers and have fitted 1.6 discs and pads or is it true that this cant be done??

whats the part numbers/significant differences in the 1.6 and 2.0 callipers please?

thanks you

[wwmnw]

Opening a can of worms talking about discs warping, apparently they don't warp its deposits from the brake pad being left on the disc surface.

With one qualifier, presuming that the hub and wheel flange are flat and in good condition and that the wheel bolts or hat mounting hardware is in good condition, installed correctly and tightened uniformly and in the correct order to the recommended torque specification, in more than 40 years of professional racing, including the Shelby/Ford GT 40s – one of the most intense brake development program in history - I have never seen a warped brake disc. I have seen lots of cracked discs, (FIGURE 1) discs that had turned into shallow cones at operating temperature because they were mounted rigidly to their attachment bells or top hats, (FIGURE 2) a few where the friction surface had collapsed in the area between straight radial interior vanes, (FIGURE 3) and an untold number of discs with pad material unevenly deposited on the friction surfaces - sometimes visible and more often not. (FIGURE 4)

http://www.stoptech.com/tech_info/wp...rakedisk.shtml

Its also unlikely you have Corsa GSi calipers and 256X24 discs as a mate accidentally tried to fit some 256X24 discs in his Corsa GSi calipers, the discs got jammed by the brake pads and couldn't really turn.

Edit: Sorry you've put 2.0 calipers and 1.6 discs, I doubt it too as the disc wouldn't be wide enough

[Jedro]

hmmm, whats the warping cause then, i cleaned them up about 2 weeks ago and it didnt make a difference to it. its not really bad just when im doing 60ish and brake hard the steering wheel wobbles. cant be other issues because when they were new it was spot on. confused

[Stuart]

When you say cleaned, what does that mean......

Are you sure the runout is as low as possible with the hub face etc.

[Jedro]

When you say cleaned, what does that mean......

Are you sure the runout is as low as possible with the hub face etc.

will check that doh

i emery clothed the discs and used the very small amount of copper-slip i had left on the callipers

that screw that hold the disc in place before you put the wheel on is missing on one side but cant see that being an issue when the wheels are tight

[Stuart]

Emery cloth wont remove the uneven deposits.

I'd go and bed the pads in again and see if that makes the transfer layer even again

[AndrewJenkins]

have you checked all the sliders are free too?

[AlexW]

Probs the rear brakes.

[Jedro]

have you checked all the sliders are free too?

they seem fine tbh mate

[Jedro]

Probs the rear brakes.

dont think so bud as the wobble disappeared when i first changed the fronts.
check your u2us on CS mate