[mk2 1989 golf gti 16v
tried my brakes out during some hard driving tonight, i find that i can repeatedly lock the o/s/f wheel over and over ..same thing hot or cold brakes
everything seems to be in good order , new braided hoses that were well bled , recent discs and pads , matching tyres etc
it recently passed a mot , so it cant be that uneven, and it pulls up in a straight line , so should i be concerned? i found i could lock the o/s/f at 40mph wit hot brakes is that normal
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Tyre pressures?
Mk2s suffer with rear handbrake levers seizing and not returning to their stops, this causes the rear callipers not to auto adjust, is the n/s/r lever returning to its stop?
Is the rear brake load compensation valve seized? When you bled the brakes did you clamp the valve open to expell all air from the system?
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the handbrake is all sweet with new calipers and bled with the valve cranked open
its the front wheel that locks...not sure if the rear would effect that?
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Could be a sticking caliper.
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Getting the front wheels to lock on a pre-ABS car isn't difficult, and usually isn't particularly dangerous - the only limit to the fluid pressure is given by the *strength of your legs!, whereas the rear brakes are limited by hydraulic valves. I would check the brakes, taking particular care with the passenger side caliper and pads - ideally you would lock up both front wheels at the same time if all other things were equal.
If the brakes are OK, one other thing that could cause asymmetry in locking the brakes is anything that causes the car to sit un-evenly. In this case, the cause can be either at the front or rear. The Golfs do sometimes rot out the rear upper spring retainers, which takes load off the affected rear wheel, and the diagonally opposite front wheel.
* typically, this is above the level of assistance provided by the servo - i.e., the servo has saturated, and is providing maximum assistance, the servo force at this so-called knee point is given simply by the area of the diaphragm multiplied by the pressure drop across it, i.e., almost atmospheric pressure.
Number_Cruncher
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Chaeck all corners for a broken road spring or a seized or shot shock absorber, Also chaeck the rear beam bushes are not despabilising the car under breaking. Mind you the MOT chould have picked that up as it should if a tyre was fitted on the wrong way round. Check if you have a set with rotation arrows. Regards Peter
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If it pulls up in a straight line then it is not really worth worrying about and if the imbalance was too much then it would have failed its MOT. If you manage to repeatedly lock up a front wheel whilst 'doing some hard driving', may I suggest that you steady on a little before you end up writing the car off?
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thanks guys...i will have the fronts apart and clean and inspect it all
simon..i just happend to nip it up on a damp road...then i purposely did it again to see if i could repeat the o/s/f lock up...i dont usualy drive like a fool
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You may not actually solve this problem, although I wouldn't really class it as a problem from what you have described anyway. If it is a Mk2 Golf then it is getting on a little in its years and it could simply just be a case of one caliper being slightly lazier than the other. It may not even be a related to the calipers at all, it could be something as simple as different compound tyres, worn suspension, or even the brake master cylinder/pipework. I wouldn't go to extreme lengths to fix something that isn't actually broken.
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