MK1 Brake Mods

[oracle1]

Hey MK 1 crew how are we all?

I have put larger vented rotors on my MK1 and left the old brake master cylinder and booster on. Will this setup run the brakes ok for a roadworthy? Do I have to do the mod with the booster?

I have everything working on my mk 1, the 5 speed, coil overs in, small amount of electrics eg no wipers and indicators remaining and I am set for my roadworthy. Does anyone know of someone in Brisbane who loves these cars that does a roadworthy. The five speed in the mk1 with diesel goes really well.

Thanks for the advice guys

Regards,
George

[Peter Jones]

Just doing the front discs will be fine, that's the same way the GTIs were set up.

The bigger master cylinder is a must if you go to rear discs though.

The booster mod would be a further improvement on what you've done already.

Pete

[Golf Loon]

Mk1 GTI Boosters are bigger.
The standard one on your car will be fine, but go over the linkage bar setup between the pedal and the booster and take all the slop out of it, also make sure all the bushes are ok.
Obviously also make sure the brakes are bled up well.

[oracle1]

Guys per Matt's instruction I went with the larger drum brakes rather than the disks, which I haven't fitted yet,will this still run on the small booster?

[dubai gti]

I'm now running the rear Cordoba-drum upgrade and vented-front discs on what would be a std. Cabrio. brake booster and it all works fine..

[JP-009]

I'm now running the rear Cordoba-drum upgrade and vented-front discs on what would be a std. Cabrio. brake booster and it all works fine..

Is the Mk1 Cabrio brake booster bigger/more effective than the non-cabrio booster? If so, is it a straight swap (with no further mods)?

[JDVW]

pretty sure all mk1 booster's are the same. i put '82 gti calipers and vented rotors on my '79 gls and didnt change over the booster and it brakes fine

[JP-009]

pretty sure all mk1 booster's are the same. i put '82 gti calipers and vented rotors on my '79 gls and didnt change over the booster and it brakes fine

Do the new calipers and vented rotors help braking (reduce distance)? Or does it mean you can abuse/use the brakes more with no brake fade?

Sorry for the silly questions.

[JDVW]

deffinatley reduced distance as your doubling the pad surface on both sides of the disc. i found my original brakes got hot really quickly and started to squeak
and lose effectivness no troubles now though!

[dubai gti]

deffinatley reduced distance as your doubling the pad surface on both sides of the disc. i found my original brakes got hot really quickly and started to squeak
and lose effectivness no troubles now though!

agreed, I noticed my old, solid discs had a bit of fade when really hot...yet to fully bed the new vented discs in....

[Jarred]

New discs will put you up faster and wont fade as quickly.

Bigger booster gives a more modern pedal feel (requiring less imput for the same result) and a bigger MC pushes more fluid for greater stopping force.

[Golf Loon]

New discs will put you up faster and wont fade as quickly.

Bigger booster gives a more modern pedal feel (requiring less imput for the same result) and a bigger MC pushes more fluid for greater stopping force.

Plus replacing 30 year old parts with new or newer stuff will make a massive different

[hiho]

A few clarifications

going from solid to vented discs of the same outer and inner disc braking surface (mk1 solid to mk1 GTI vented for instance) wont make any difference to the maximum braking force/decelleration (all other things being equal). what will improve is your brakes resistance to fade as the vented disc will dissipate heat faster.

a bigger booster will increase the pedal sensitivity, reducing the require force applied by the driver (not a bad thing in a Mk1 with the linkages between the pedal and the MC/booster)

increasing the diameter of the master cylinder will reduce the travel of the brake pedal, but make it harder to push (this is because the larger diameter MC piston displaces more fluid per unit of travel)

decreasing the diameter of the master cyclinder will increase the travel of the brake pedal, but make it easier to push (as the piston is displacing less fluid.....)