Rear Disc Conversion - 19/01/2011

[richard ellison]

ordered my brake upgrade today from TSR.

upgrade to 270mm (or 285mm) discs, pads, carriers and spacers and braided hoses for ?340.

C&R are more pricey but know much much more about the process of brake upgrades. spoke to them today and the bloke knew everything! any of you with questions should give them a bell. very helpful.

[drewwagar]

Folks,

A word to the wise. I would not recommend a rear disc conversion on a mk1 if you intend to drive it 'properly'. The mk1 weight distribution coupled with the rear compensation will mean you always have an overbraked rear axle.

The same goes with the front discs. Upgrading them to 256 (or perhaps 270) mm is ok, but no further. The mk1 doesn't need anymore braking than this due to its light weight. An overbraked car is more dangerous than an underbraked one in most conditions, particularly if road grip is compromised, you simply wont be able to cadence brake effectively.

If you are serious about improving the braking, rather than just the looks (yes drums look horrible!) service the original components first. There is actually nothing wrong with the configuration of the original cylinder, cross linkage, servo discs and drums IF PROPERLY SETUP, LUBRICATED AND MAINTAINED.

The mk1 'brakes are crap' is a myth, caused by people jumping into 20 year old cars with brake systems which have been poorly maintained over that time. There were no complaints about the brakes when the car was new.

You can virtually remove the soggy lifeless pedal feel if you dismantle and lubricate the cross linkage and servo actuator.

My mk1 has been hammered around castle coombe for over and hour at full tilt with no problems on standard rebuilt braking gear. (Yes, 239mm VW discs and pads.)

Be careful out there.

Cheers,

Drew.

[drewwagar]

As for the mk1 with drums on the front... The very early 1975/6 had drums all round, but the definitely shouldn't be on any 1983 golf, particularly a GTI.

All GTIs had 239mm ventilated front discs.

Cheers,

Drew.

[richard ellison]

I see what your saying drew, but you surely cant say the brakes are good.

Maybe tintops are different to the cabs but mine sure doesnt feel safe with heavy braking at 60mph+

Modern cars have much much better brakes, hence why an emergency stop in the mk1 would take much longer than in a new car....

thats my view anyway

Rich

[ridgers]

The only reason you normally fit discs to the back of the MK1 is to take out the long amount of play in the pedal, as by there very nature disc brakes adjust easier than drums.

I would sasy you would have no problem fitting them to the back AS LONG as you adjust the brake compensator to make sure your got going to lock up the rear wheels. You should adjust it when you lower the car also as this effects the braking balance but not a lot of people do.

The MK1 brakes are crap myth isnt a myth it is true, MK1 brakes are crap I've had both a MK1 golf and scirocco storm so know that this is due to the fact you have a cross linkage rather than a direct acting servo.

[BobbyT]

i have got mk2 16v calipers and black dimond disks and pads but the brakes still feel wank? used to have a nova (no piss taking please) and if you fitted disks to the back of them they used to spin under heavy braking! so what can i do to improve the braking without fitting disks to the back? rob

[richard ellison]

its bascially as bigger discs as possible. 270 or 285 do the job well, and fast road pads help aswell. ive got pagid ones.

[richandhazel]

I still haven't done the conversion yet, but do still intend to. Drew, Mark999, your warnings are heeded and I agree valid points however I also agree with Pete that you must be able to adjust the brake bias compensator to reduce the braking on the rear. That is what I intended to try anyway. My cabrio is not a day to day driver and I intend to carry out this mod purely for cosmetic reasons.........I will get round to it one day, honest!

The braking on a mk1 has always been debated and there is no doubt that it takes a lot more effort than a modern car. However, you do get used to them, just like two similar cars with and without power steering. At the end of the day, surely if you can lock the wheels up then you have more than enough braking ability...........any mk1 I have ever driven it has always been possible to brake so hard as to lock the wheels, not that you would want to, obviously.

[Jelly]

I haven't done the conversion yet either, but I am planning on. I am building a Mk1 race car so the brakes are an area I am going to spend time and money on. Tbh the brakes on my Mk1 were not 'that' bad for general road use and even when I upped the pace considerably they still worked, mainly because I got used to the limits of the brakes, when they lock up etc.
I agree with Drew, the braking system on a Mk1 is going to need looking after and servicing. Its amazing how people will jump into a 25 year old car and drive it hard, trusting the brakes to work just like a modern car.
The limiting factor I have to overcome is heat build up and brake fade. Whist air ducting is crucial to this, the rear discs will help give more braking power to the rear (how much, can be adjusted)

Obviously people use the Mk2 rear disc setup for Mk1's. Does anyone know if modern rears from, say, a Mk4 Golf or even 9n Polo can be used 'easily' (anything CAN be used lol)?

Jelly

[Judderi]

Folks,

A word to the wise. I would not recommend a rear disc conversion on a mk1 if you intend to drive it 'properly'. The mk1 weight distribution coupled with the rear compensation will mean you always have an overbraked rear axle.

Yes but you can adjust the compensator. Or do you mean that you cannot adjust it enough?