Brake Pedal height/travel adjustment on MK2 Golf

Discussion in 'Chassis' started by Nige, Jan 23, 2007.

  1. Nige

    Nige Paid Member Paid Member

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    I`ve searched the threads and not found a definative answer.

    In pursuit of the brake pedal feel I expect the setup should give me, my final option is to adjust the brake pedal rod that operates the Master Cylinder.

    When warm, the braking performance is totally acceptable, I have no problems with that AT ALL. However, even after all the work I have done, there still appears to be dead travel when for the first 1" or so, the pedal does NOTHING at all, I have jacked the car up, had someone press the pedal whilst I spin the wheel, and for that 1", there is no effect, after that, the brakes start to bite. Looking at the pedal, there is the adjustable rod that operates the Master cylinder via the servo, I`m pointing to it here:

    [​IMG]

    If I adjust that at all, it just adjusts the pedal height, BUT if I put a locked bolt into the hole above the brake light switch to limit the pedal height (the same as the clutch pedal), can I then not adjust the rod, which will in effect simulate the pedal being pressed a certain amount all the time?

    [​IMG]

    I realise that when used on track the brakes heat and the pads need room to move to back off the disc, so I know I cant go silly or i`ll end up with locked brakes when they get warm.

    By adjusting this rod by only half a turn, I removed most of the dead travel, another half turn gave me exactly the pedal feel I was after, almost instant effect when pressing the pedal. I have backed it off to where it was originally until I get some replies from the experts in this thread.
    [​IMG]

    My question is, would I be OK leaving it adjusted 1/2 a turn (or whatever fine tuning requires) to get the pedal to brake without the 1" of dead travel?

    If I cant do this, could someone let me know why, there could be a perfectly plausible reason that I just dont know about.

    Nige.
     
  2. 13"rims Forum Member

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    i like what you've done mate! But im no expert! i have this problem on my mk1, what car is this on? you've taken the "slack" out of the pedal travel, i guess by reducing it from 1" to half " there's no real danger as opposed to going the full inch and possibly having the brakes partially on all the time. maybe 3/4 turn wud work out fine?
     
  3. Nige

    Nige Paid Member Paid Member

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    13", if you loosen the locknut, you can adjust the bar with your fingers, its dead easy, you can actually `feel` when the slack has been taken up, another 1/8 of a turn or so and the brakes are SO much better. I`ve read of people doing it on MK1`s, but not a MK2. To be honest, I`m really suprised nobody else has ever done it on a MK2, it makes a MASSIVE difference, no `slack` in the pedal as you rightly point out.
    Thats what makes me think I`ve done something bad, seeing as I`ve not seen anyone else do it before !!
     
  4. I V - mk1 16v Forum Member

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    As i mentioned Nige, i did this on the mk1 but went too far and got locked wheels once the brakes got hot and binding brakes when they were just warm. To stop this completely i ended up having to back the adjustment right back to pretty much where it was in the 1st place.

    Have a play and see what results you can get, but just make sure you get the brakes properly hot when you test it. Again i thought i got them as hot as i could (on the road) but 3 laps on track locked them up, and that was at Curborough a tiny little circuit!! (bedford is hard on brakes by the way, so you could always play on the day.)

    Do the ds2500'S need much warming up??
     
  5. Nige

    Nige Paid Member Paid Member

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    Its a 15mm Spanner to undo the locknut then the bar twists with your fingers, dead easy.

    I will leave it at 1/2 turn from where it was originally, then tweak as necessary at Bedford on its trackday debut, when the brakes are HOT. I`ll err on the side of caution to ensure I dont get binding brakes though.

    The DS2500`s do need warming up, but I dont know how much compared to others on the Golf, they are the only ones I`ve ever had !

    Cheers,

    Nige.
     
  6. 13"rims Forum Member

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    probably obvious but do you mean this?

    [​IMG]
     
  7. Nige

    Nige Paid Member Paid Member

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    thats it mate. Thats the BAR, the locknut is visible, the slightly larger HEX head you can see...
     
  8. 13"rims Forum Member

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    lol alright alright! just making sure!
     
  9. AxlFoley Forum Junkie

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    could it be do to with the caliper, servo and master cilinder setup you are using, i know that if you run Mk2 GTI brake calipers on a Mk2 Driver youhave exessive play, that is untill you fit the GTI master cilinder and Servo, it could be worth you looking in to this.
     
  10. Nige

    Nige Paid Member Paid Member

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    Its on a MK2 GTi, with 22mm MC, I`ve changed everything, the brakes work well, once they get past that first 1 inch where nothing happens...
     
  11. AxlFoley Forum Junkie

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    is it deffinaly an inch, im sure there should be some play, but not that much, i know this is a stupid question, bt is it all fitted together properly ?
     
  12. Hotgolf

    Hotgolf Paid Member Paid Member

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    Don't listen to axl, he's bumped 2 cars in as many months.
    Mark, the brakes in the middle mate:lol:
     
  13. AxlFoley Forum Junkie

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    actualy its 3 cars, and 4 acidents, but only two were my fault ;)
     
  14. Nige

    Nige Paid Member Paid Member

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    LOL.

    Yeah, I am 100% everything is fastened together as it should be, new disks, pads, braided hoses, brakes pipes, fluid (pressure flushed and filled) and new 22mm Master Cylinder !

    If you could actually see the pedal, you`d understand exactly what the problem is. By turning the threaded bar 1 full turn, then locking the locking nut, the pedal only has a tiny bit of dead play before the brakes start working.

    I`ve taken it for a run again today and even when the brakes are HOT, it doesnt quite bind, although the dead play vanishes, so i`ve backed it off 1/4 turn and I`ll see how that goes.

    If you have lot of pedal travel before the brakes engage and you`ve done the usual, bleeding etc, this MAY be a solution. Make sure you dont overdo it or when the brakes get hot, they will stick on !!
     
  15. rubjonny

    rubjonny Administrator Staff Member Admin

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    just a quick question on this, if I just adjusted this on its own, it wouldnt effect the free play in the MC at all would it? Basically my brake pedal is lower than my clutch pedal, and was wondering if I adjust it so the pedal is level, the free play at the cyliner would be uneffected?

    I was also wondering if someone had lowred the pedal to remove some free play, but might be causing my discs to bind on, and explain my shocking MPG. But if they had, moving the pedal down on its own wouldnt actually affect the ammount of free play, am I correct?
     
  16. Nige

    Nige Paid Member Paid Member

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    If you DONT fit the bolt (silver one in pic 2), adjusting the bar in pic 3 will raise the pedal, without affecting the MC at ALL. The bolt means that the pedal will not adjust upwards, so that pushes the brake bar into the MC. Hope that makes sense??
     
  17. Fenn Forum Member

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    interesting tread. but i would be concerned that if you adjusted the MC bar to far, it won't let any brake fluid in from the MC bottle.
     
  18. rubjonny

    rubjonny Administrator Staff Member Admin

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    cool thats what I thought. Scratch the idea of a badly adjusted pedal causing brake drag...
     
  19. jamesa Forum Junkie

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    NigeP

    I have the same `free` play in both my Mk1 and Mk2 GTI`s and don`t find it an issue on road or track. When on track I find that I don`t need that immediate feel in the pedal as I`m stamping on the brakes anyway and don`t notice it.

    Why do you think you need the brakes so sensitive ?

    With regard to your `mod` that takes up the pedal travel - I`d think carefully before running that on the road as in the case of an accident it may be classed as illegal ?

    I don`t wish to sound critical .... just my point of view & experience.

    Is your Servo unit OK ?

    Is the fact that you are running hard pads contributing to this ?

    I use Pagid Fast Road pads and find them an excellent compromise for road & track

    Hope you get it sorted ...
     
  20. mexicorich Forum Member

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    I know IV has a very well sorted car and have been tempted to pay him some mney to buy it, but I'm lost as to why hot brakes on a Mk2 would have any effect on the dead play? (even on a Mk1 with its rods and pivots).

    If the piston in the master cylinder returns to its end position when the brakes are not applied, this is determined by the locking circlip in the end of the MC. This position still won't be any different when the car is hot, so geometry of external pushrods would be expected to be unaffected.

    So what else is there between the MC and the rod from the brake pedal that we want to adjust the length of - well its the servo

    Do we think the servo then behaves differently when stinking hot to merely warm?

    From what I can remember of dismantling servos over twenty years ago, there is nothing to suggest the dimensions of the input/output rods will change when the servo is in use?

    IV has clearly experienced something occuring but can anyone rationalise it for me?
     

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