Shaking under braking

[RichyB]

Hi there, having a problem with my mini shaking while braking. There's no problem when driving along normally, but the car shakes violently when the brakes are applied. Tried changing the discs, put new wheel bearings in but neither fixed the problem. Found that the drive flange on one of the wheels was missing a bolt though and the drive flange spacer was pretty wrecked, could these be causing the problem?

Thanks in advance, Richard

[joebe1]

If the big castle nut is missing thats a serious problem, you ll lose the wheel. Replace the taper washer, thats why the nut has come lose in the first place. check the other side just to be safe, I think there 50 foot pounds torque, or bounce on a long tommy bar and socket.

I ve seen the pads to slip out of place if the spring plate breaks and or split pins are not inserted correctly, which gave me the same result as your getting. Ensure the calipers are both working correctly, get someone to press the brake, you see the pistons move enough the see there working, other than that grab the wheel and shake it to ensure there no big movement

Joe

[woody]

joebe ,I think he means one of the bolt between the drive flange and disc not the castle nut. My brother is having the same problem at the moment with serious vibrating under braking, changed discs, did balljoints ,changed subframe mounts and can't find problem.

[RichyB]

Don't worry, castle nut is still there, torqued correctly! Ball joints seem fine, subframe mounts are probably fairly knackered, could that cause the shaking? One of the spring plates that hold the pads in is broken but still seems to be holding in the pads fine. Callipers are working grand, the brakes work, the whole front end just wants to shake itself off the road..

[joebe1]

Thats good It would nt do to lose the wheel , any chance of the subframe cracked at the bottem mount, they go? Wheels balanced?

[GTM Coupe]

Possible warped disc? or damaged/buckled wheel

[RichyB]

I bought some discs off Tony but they didn't help, subframe mounts have been tightened but the problem is still there.. Even at high speeds theres no shaking or vibrating while driving, but once the brakes are on it feels just like a warped disc. At low speeds it feels like the brake is biting then releasing with each turn of the wheel, which made me think it was a warped disc, but changing them didnt help..

[keith]

you seem to be running out of options to check....

try swapping the front wheels & tyres to the back.- just to eliminate that as a possibility.

also worth checking the condition of the tie-bar bushings - they deform a good bit when braking. iirc one of the tie bar bushes is softer than the other; i always put the harder one just behind the nut, facing forward: that's the one that takes all the stress as you stand on the brakes.

[RichyB]

Yeah, it's an annoying problem... I'll try swapping the wheels and I'll have a look at those bushings. Might try swapping the whole wheel hub and disc set up from my Dad's Mini onto mine and see if that does anything! At least then I can narrow down my search.

[keith]

i know its tedious, but quicker in the long run: swap things one at a time (always a pair, left & right) and *always* try the easiest things first!

[daniel garry]

try your tracking, as you brake most of the weight shifts onto the front wheels so it'd exagerate any bit the tracking's off

[CLUBMANGT]

Have a look at the floor where the subframe mounts at the rear , it can crack and I have seen it cause this sort of problem as the frame moves about

[woody]

We had the floor crack and repaired it but didn't solve the problem.Talking to Eamon last night he once had a simular problem which turned out to be the back brakes had a doggy cylinder. Will cheak this out as I know there was a problem before with the brakes on my brothers car.

[RichyB]

Turns out it was warped discs after all! Put two new ones on and that solved the problem. Thanks for the help everyone!