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Model specific boards => Golf mk1 => Golf mk1 how to guides + info => Topic started by: vixteris on 14 April 2004, 00:24

Title: Rear Disc Conversion - 19/01/2011
Post by: vixteris on 14 April 2004, 00:24
my cab has drum brakes on the back wheels and i wondered if they could be easily changed over for discs???

has anyone done it and do all the mark 1's have them - even the later cabs??

----------------------------------------

SoundillusioN Link Update

HERE (http://www.vintagewatercooleds.com/tech/Techtips/ATStechnotes/reardisc/reardisc.htm)
Title: Re:drum brake conversion
Post by: richandhazel on 14 April 2004, 05:01
As far as I know, all the mk1's have rear drum brakes unless modded.

I'm going to change mine to discs, mainly because they look better. I have the discs and calipers from a mk2 and believe they are a straight swap. I think you need to use a different handbrake cable........one from a Scirocco if memory serves me correct.
Title: Re:drum brake conversion
Post by: vixteris on 14 April 2004, 19:08
thanks rich - i only want to swap for the looks as well, finding a scirocco hand brake cable might be fun :D
Title: Re:drum brake conversion
Post by: old_boy on 14 April 2004, 19:33
Hi Vix,
16v Scirocco handbrake cables are easily obtainable from VAG, last time i bought some they were about ?18 a piece.
if you didnt want to pay that you can shorten the golf handbrake guide tubes on your car and use MK2 cables, but i would'nt recommend this as its a pig of a job to reverse, other than that, its a straight forward bolt on job, but you need to make up something to hold the flexi hoses to the trailing arm-hope this helps. :)
Title: Re:drum brake conversion
Post by: richandhazel on 15 April 2004, 10:41
Thanks for that info Jim. I'm going to copy this thread and add it to my growing list of 'useful technical posts', so if anyone else has anything to add I'd be very grateful. :)

I had a suspicion it was 16V Scirocco handbrake cables needed when I saw line 15 of the parts list at GPC:-

http://www.gpcvwaudi.com/golf1.htm (http://www.gpcvwaudi.com/golf1.htm)
Title: Re:drum brake conversion
Post by: AdamB on 15 April 2004, 10:47
If anybody does do this conversion, can they take some step by step photos as this is probaly a modification a lot of mk1 owners would like to do, me included.
Title: Re:drum brake conversion
Post by: richandhazel on 15 April 2004, 10:53
Good idea,
I'll do it after inters and VW Action Adam........full step by step by guide with pics ;)
Title: Re:drum brake conversion
Post by: old_boy on 15 April 2004, 11:06
Some people have also reported that you need to grind a couple of mm's off the edge of the trailing arm to enable you to fit a bolt to the caliper carrier, but i have never come accross this problem, but it is quite tight!
Due to the cost of stub axles, most people use second hand parts, which is what i did on my first conversion, just make sure you dont get a slightly bent one (like i did- ::)) as this throws out your wheel geometry and you start getting strange tyre wear, this couldnt be seen upon fitting, but soon showed up when i had a computer 4 wheel line up thingy!
Title: Re:drum brake conversion
Post by: richandhazel on 15 April 2004, 11:24
I've got an F plate mk2 GTI that I was going to use as the donor car so should be cheap - cheap, just time and labour envolved......I hope.
Thanks again Jim. By the way, are you coming to any of the shows this year? Be good to see you and the family.........
Title: Re:drum brake conversion
Post by: mk1 on 15 April 2004, 18:51
I think the hand brake cable part # is  533 609 721
Sirocco with rear disc's.
May look into doing this also as most of the other work is now done (and the brakes do seem a bit marginal :o)
Update....
Fitted the disks today, no problems. Have to find a way to secure the flexi to the rear arm, top carrier bolts ,as Jim said, can be close. Pedal seems a bit long, have bought a 16v m/cylinder (22mm) and will fit it over the week end and advise.
Steve.
Title: Re:drum brake conversion
Post by: danhock on 29 April 2004, 09:22
You'll have to be careful when doing this mod..

you gotta remember that the brakes are setup for drums so putting discs at the back will completely throw the braking balance between front and rear.. (usually biased to 80%+ on front).

I had a mate who did this on his track car and used a manual brake adjustment setup up in the cockpit (dial which restricted brake fluid going to the rear).

The only real reason for doing this mod is for looks and as it actually compromises safety may not be worth doing.....
Title: Re:drum brake conversion
Post by: golfvr6 on 01 May 2004, 00:40
Does the mk1 not already have a rear compensator?
Title: Re:drum brake conversion
Post by: SoundillusioN on 01 May 2004, 11:58
Not sure if this is what you mean but, On the Mk1 there's a Brake pressure regulator located just in front of the rear axel (drivers side).  Its connected to the axel via a spring.  Its meant to adjust the brake pressure at the rear according to how much the car is laiden.  I'm not sure how serious, but I believe the rear brakes on the car can be a bit over powering if the car is slammed because the reg thinks the cars got a tonne of bricks in the back due to the height (or lack of it).  I'm sure this regulator can still be used and will still work with a rear disc conv since its only part of the brake lines.   :)
Title: Re:drum brake conversion
Post by: golfvr6 on 01 May 2004, 14:38
Yeah thats what i meant.
If the rear lock up then adjust the valve so there is less tension in the spring.
Title: Re:drum brake conversion
Post by: old_boy on 01 May 2004, 15:48
This is something which gets overlooked when people put disc's on a MK 1, as I did  ::)
My wake up call was on a slight downhill bend, as I was giving it large and I hit my brakes, the rears locked up and spun me 180, so I was facing the cars that were following me. :o
The way to adjust the compensator valve is this......
With your cars wheels stood on the ground, IE, no jacks or ramps, you need to get under the N/S and locate the valve, find the spring attached to the lever and you will see a 13mm nut and bolt.
So armed with a 13mm socket and spanner (and WD40-because all MK!'s are rusty) JOKE, loosen the nut and bolt on the spring until the spring is just starting to take up the tension on the lever and then tighten-HEY-PRESTO-properly balanced braking, with no brown trouser moments!
Whilst under you car, its a good idea to check that the lever on the valve moves freely and the pipes are in good nick.
Another important thing to remember is that if you subsequently lower your car, you will need to do the above again or you may wish you were wearing bycycle clips. ;)
Dont forget-the car must be supporting its own weight. 8)
Title: Re:drum brake conversion
Post by: richandhazel on 02 May 2004, 11:35
Nice one.........something I would have overlooked too. Glad I made this sticky, some good points and tips being raised ;)
Title: Re:drum brake conversion
Post by: SoundillusioN on 21 May 2004, 19:46
So has anybody had a go yet?  ???
Title: Re:drum brake conversion
Post by: richandhazel on 22 May 2004, 11:21
I plan to. I ripped the brake calipers, carriers, discs and stub axles off that mk2 I just scrapped with a view to fitting them to the cabrio. The calipers aren't in very good condition so I need to delve into my shed and dig out another set I kept from a previous mk2 that I broke. Once I've got all my bits and pieces together I'll give it a go. I'll take lots of photo's with a view to creating a step by step guide.
Title: Re:drum brake conversion
Post by: SoundillusioN on 22 May 2004, 15:10
Can't wait because if it?s successful I'd be tempted to do the same as part of my GTI's resto.  :)
Title: Re:drum brake conversion
Post by: mk1 on 22 May 2004, 17:09
I also have the calipers etc (a morning at the scrappers well spent ;)).
Have to o/haul the calipers and clean up the parts.
Will keep you all posted.
Steve.
Title: Re:drum brake conversion
Post by: Madds on 27 May 2004, 12:24
Hi all,

New to the Gti Scene (just bought my first one).
Mines got drums on the front, which fair to say isn't too hand at braking.
Whats the best way to convert to disks front end?

Cheers.
Title: Re:drum brake conversion
Post by: SoundillusioN on 27 May 2004, 18:32
 :o Drums on the front? r u sure?
Title: Re:drum brake conversion
Post by: Madds on 27 May 2004, 19:48
Absolutely sure. I'm no mechanic, but I recognise drum brakes.
Is this rare then? Its an '83 so not that early.

Does everybody else have disks on the front then?

 ???
Title: Re:drum brake conversion
Post by: mk1 on 27 May 2004, 20:54
Mk1 golf with drums on the front? (between you and me, the brakes are a bit marginal with disks  ;)). Take the wheel off and post a picture.
Steve.
Title: Re:drum brake conversion
Post by: richandhazel on 28 May 2004, 00:28
Never heard of drums on the front of a Golf.....any Golf for that matter....post pics ;)
Title: Re:drum brake conversion
Post by: SoundillusioN on 28 May 2004, 11:20
I'm still puzzled about this, an 83 on drums all round, I don't dispute ur judgement but that is so weird!  :o.  Has somebody done a beetle brake conversion or something! lol..  Please post pics, curious on the setup...

Shaun
Title: Re:drum brake conversion
Post by: Madds on 02 June 2004, 17:17
Its in the garage at the mo having the fusebox replaced. As soon as I get it back I'll take some pics. Thought it was dodgy myself to be honest but just thought it was one of those things.
Drums all round on my split, and that doesn't move half as quick.

Pics next week with any luck.

Cheers so far,
madds

Title: Re:drum brake conversion
Post by: Dizzie on 12 June 2004, 23:37
the mk1's brakes were bad enough with discs on the front let alone drums!

vix, that scirocco I got your heater controls might have that cable, but they're only ?15 new you may aswell buy one of those.
Title: Re:drum brake conversion
Post by: kraM on 28 July 2004, 23:06
errrrr... a note on the side of caution... the back of a golf is very light, therfore if you have to brake hard there is a high possibility of the ba*tard swapping ends, the caddy weighs less at the back, and unless it is rammed with ICE or 'well feed' mates the problem could be much worse.
Make sure the brake ballance valve works properly, take it to an MOT station and get the efficency tested, they should be able to tell you if it is ok and working etc.  
Sorry for the gloomy message, but from past experence, pulling a 180 on the exit of a tight is cornor, whilest out on a 'rag' and having to reverse away from your following mate at 50ish  is pant filling for all involed... :o :o :o :o
Title: Re:drum brake conversion
Post by: richard ellison on 08 August 2004, 21:48
errrrr... a note on the side of caution... the back of a golf is very light, therfore if you have to brake hard there is a high possibility of the ba*tard swapping ends, the caddy weighs less at the back, and unless it is rammed with ICE or 'well feed' mates the problem could be much worse.
Make sure the brake ballance valve works properly, take it to an MOT station and get the efficency tested, they should be able to tell you if it is ok and working etc.  
Sorry for the gloomy message, but from past experence, pulling a 180 on the exit of a tight is cornor, whilest out on a 'rag' and having to reverse away from your following mate at 50ish  is pant filling for all involed... :o :o :o :o

im not sure if that would be the case if you uprated the discs on the front as well as the rear convo... then the balance would the similar- heavier braking from the front....
Title: Re: drum brake conversion
Post by: richard ellison on 01 September 2004, 21:16
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.
Title: Re: drum brake conversion
Post by: drewwagar on 03 September 2004, 17:47
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.
Title: Re: drum brake conversion
Post by: drewwagar on 03 September 2004, 17:55
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.
Title: Re: drum brake conversion
Post by: richard ellison on 10 September 2004, 19:04
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
Title: Re: drum brake conversion
Post by: ridgers on 29 January 2005, 15:33
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.
Title: Re: drum brake conversion
Post by: BobbyT on 22 February 2005, 20:34
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
Title: Re: drum brake conversion
Post by: richard ellison on 24 February 2005, 14:04
its bascially as bigger discs as possible. 270 or 285 do the job well, and fast road pads help aswell. ive got pagid ones.
Title: Re: drum brake conversion
Post by: richandhazel on 18 March 2005, 16:42
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.
Title: Re: drum brake conversion
Post by: Jelly on 03 August 2005, 09:44
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
Title: Re: drum brake conversion
Post by: Judderi on 06 September 2005, 12:01
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?
Title: Re: drum brake conversion
Post by: dubburke on 25 September 2005, 10:45
Just to add my bit :grin:
I dont think the discs at the rear are needed, even with big power :wink:
New dot 4 fluid as this gets neglected, and without it being in tip top condition brakes will fade :embarassed:
Just concentrate on the brake linkage, and get that spot on, braided hoses, 16v servo and m/c, a good quality pad and grooved discs, maybe grooved drums just for good measure and make sure the drums are adjusted properly
Title: Re: drum brake conversion
Post by: Madone_si on 28 September 2005, 14:20
steps are outlined at this website.

http://www.vintagewatercooleds.com/tech/Techtips/ATStechnotes/reardisc/reardisc.htm
Title: Re: drum brake conversion
Post by: G60GTI16V on 22 July 2007, 22:22
If you do this conversion, do you think you have to use a bias valve to adjust the pressure to the rears? I think you will have to, am i right?
Anyways i think its stupid because the golf had alot (i mean alot) of research & design before they actually made sale of the cars and everything that came on the car once bought from the showroom is its recomendations and shouldnt be altered.
Dan
Title: Re: drum brake conversion
Post by: Madone_si on 03 August 2007, 01:12
If you do this conversion, do you think you have to use a bias valve to adjust the pressure to the rears? I think you will have to, am i right?
Anyways i think its stupid because the golf had alot (i mean alot) of research & design before they actually made sale of the cars and everything that came on the car once bought from the showroom is its recomendations and shouldnt be altered.
Dan

yes you are right... if you want to understand all the requirements and how to do it, the guys to ask are C&R Enterprises, they have done this conversions hundreds of times...
Title: Re:drum brake conversion
Post by: MK1 Ali!! on 29 December 2009, 17:52
Not sure if this is what you mean but, On the Mk1 there's a Brake pressure regulator located just in front of the rear axel (drivers side).  Its connected to the axel via a spring.  Its meant to adjust the brake pressure at the rear according to how much the car is laiden.  I'm not sure how serious, but I believe the rear brakes on the car can be a bit over powering if the car is slammed because the reg thinks the cars got a tonne of bricks in the back due to the height (or lack of it).  I'm sure this regulator can still be used and will still work with a rear disc conv since its only part of the brake lines.   :)

the gti compensator is suitable as it is shared with mk2 and scirocco, 84+ cabs are scirocco floor pan so it shares alot with the rocco!!
Title: Re: drum brake conversion
Post by: kraM on 16 February 2010, 20:46
Hi

I will be doing this soon, and have seen the how 2 thread, anyone want a newer version/photos when I do it?

Cheers

kraM