Uneven braking
Discussion
Had to brake a little briskly today, nothing too heavy, but it locked up my near side rear wheel. It's not the first time that this has happened i.e. pressing on a bit, brake a little hard for a bend and it locks up (always the same wheel and the others don't feel like they are struggling).
In a "lock up" situation, wouldn't the front lock first or is it the rear because what little weight there is over the back has all been shifted forward? Still doesn't explain the left/right bias.
The tyres are new and in the last two years (about 3000 miles) new (recon) rear calipers, new discs, pads, fluid, bled so I'm at a loss as to what to try next. I had to fiddle with the handbrake last month for the MOT so I know the pads were backed off equally and whilst I didn't strip down the cappiler, nothing seemed amiss. Any ideas gratefully received...
In a "lock up" situation, wouldn't the front lock first or is it the rear because what little weight there is over the back has all been shifted forward? Still doesn't explain the left/right bias.
The tyres are new and in the last two years (about 3000 miles) new (recon) rear calipers, new discs, pads, fluid, bled so I'm at a loss as to what to try next. I had to fiddle with the handbrake last month for the MOT so I know the pads were backed off equally and whilst I didn't strip down the cappiler, nothing seemed amiss. Any ideas gratefully received...
I wouldnt worry about it, sounds normal to me.
Just sounds like that was the wheel with the least weight so locked first, you reacted so the rest didnt lock.
Its normal for the rears to lock first as they have the least weight during heavy braking (look at the difference in size of discs and pads front to rear) I used to have a Polo that the rear wheels would come off the ground under heavy braking.
This is obviously dependent on road conditions etc...
Did the ABS kick in? My ABS can be a bit odd at times.
Just sounds like that was the wheel with the least weight so locked first, you reacted so the rest didnt lock.
Its normal for the rears to lock first as they have the least weight during heavy braking (look at the difference in size of discs and pads front to rear) I used to have a Polo that the rear wheels would come off the ground under heavy braking.
This is obviously dependent on road conditions etc...
Did the ABS kick in? My ABS can be a bit odd at times.
Odie said:
I wouldnt worry about it, sounds normal to me.
Just sounds like that was the wheel with the least weight so locked first, you reacted so the rest didnt lock.
Its normal for the rears to lock first as they have the least weight during heavy braking (look at the difference in size of discs and pads front to rear) I used to have a Polo that the rear wheels would come off the ground under heavy braking.
This is obviously dependent on road conditions etc...
Did the ABS kick in? My ABS can be a bit odd at times.
Thanks. No ABS on mine. Was quite a large cloud of smoke though!Just sounds like that was the wheel with the least weight so locked first, you reacted so the rest didnt lock.
Its normal for the rears to lock first as they have the least weight during heavy braking (look at the difference in size of discs and pads front to rear) I used to have a Polo that the rear wheels would come off the ground under heavy braking.
This is obviously dependent on road conditions etc...
Did the ABS kick in? My ABS can be a bit odd at times.
May just strip and grease them again to be sure.
No, it should brake straight & even and the fronts should lock up before the rears unless you provoke it (i.e. handbrake or braking while cornering) or you have braked on a dodgy road surface. If the rear is locking up first then that suggests to me that there is a problem.
Start with the easy and work along:
Tyres. Do you have the same tyres front & rear? If not, do you have the best tyres at the rear? Same across axles?
Tyre wear. Is it even across all tyres?
Tyre pressures. Should be around 26-28psi and same all around.
Brake discs. Are they all in good condition and are the pads sweeping the full extent of the disc (i.e. right to the outside edge) on both surfaces?Brake pads. Is there plenty of life left in all pads?
Brake fluid. When was it last changed?
Brakes. Are any of them binding?
Geometry. When did you last get the wheel geometry checked?
Suspension. Check for broken springs, ARB, drop-link or leaking shock absorbers.
Start with the easy and work along:
Tyres. Do you have the same tyres front & rear? If not, do you have the best tyres at the rear? Same across axles?
Tyre wear. Is it even across all tyres?
Tyre pressures. Should be around 26-28psi and same all around.
Brake discs. Are they all in good condition and are the pads sweeping the full extent of the disc (i.e. right to the outside edge) on both surfaces?Brake pads. Is there plenty of life left in all pads?
Brake fluid. When was it last changed?
Brakes. Are any of them binding?
Geometry. When did you last get the wheel geometry checked?
Suspension. Check for broken springs, ARB, drop-link or leaking shock absorbers.
Edited by MX-5 Lazza on Tuesday 28th September 09:39
MX-5 Lazza said:
No, it should brake straight & even and the fronts should lock up before the rears unless you provoke it (i.e. handbrake or braking while cornering) or you have braked on a dodgy road surface. If the rear is locking up first then that suggests to me that there is a problem.
Start with the easy and work along:
Tyres. Do you have the same tyres front & rear? If not, do you have the best tyres at the rear? Same across axles?
Tyre wear. Is it even across all tyres?
Tyre pressures. Should be around 26-28psi and same all around.
Brake discs. Are they all in good condition and are the pads sweeping the full extent of the disc (i.e. right to the outside edge) on both surfaces?Brake pads. Is there plenty of life left in all pads?
Brake fluid. When was it last changed?
Brakes. Are any of them binding?
Geometry. When did you last get the wheel geometry checked?
Suspension. Check for broken springs, ARB, drop-link or leaking shock absorbers.
Thanks for that. All tyres are brand new T1R at 27psi, brakes and pads new last year, fluid last year as well. Suspension looks fine, geo done 2 years ago (about 5000 miles)Start with the easy and work along:
Tyres. Do you have the same tyres front & rear? If not, do you have the best tyres at the rear? Same across axles?
Tyre wear. Is it even across all tyres?
Tyre pressures. Should be around 26-28psi and same all around.
Brake discs. Are they all in good condition and are the pads sweeping the full extent of the disc (i.e. right to the outside edge) on both surfaces?Brake pads. Is there plenty of life left in all pads?
Brake fluid. When was it last changed?
Brakes. Are any of them binding?
Geometry. When did you last get the wheel geometry checked?
Suspension. Check for broken springs, ARB, drop-link or leaking shock absorbers.
Edited by MX-5 Lazza on Tuesday 28th September 09:39
Will re bleed them, strip and regrease and see how it goes
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