Skip navigation

Rear brake drums to disc conversion

Post

Back to the top
Hi,

I will go through this conversion om my -87 cabriolet (1.8l) this winter and I have bought Golf mk2 calipers and carriers. I do need a bit more bits and pieces to make this happen.

I have found this shopping list:
New Scirocco 16v Parking brake cables (one for each side).
Stainless, or stock 16v rear brake lines.
brake fluid for your system.
New or used calipers, if you get used, make sure the parking brake section is not frozen.
Caliper carrier brackets.
New or used stub axles for parking brakes.
bolts for stub axle, caliper.
brake pads (new).
brake discs (new).
brake dust shield (optional, really).
Disc wheel bearings.
New grease seals - don't reuse the old ones
wheel bearing grease.
new grease caps for the bearing (might come with a bearing kit depending on where you buy).
16v Scirocco Brake pressure reducers (inline at the master cylinder).
Adjustable Proportioning Valves.

Most of the parts are no problem to find, the only exeption is adjustable proportioning valves. Where can I buy these valves now a days? Where should these be mounted? Do I need brake pressure reducers (mounted in the master brake cylinder).

Some go with mk4 brake calipers instead of the mk2 due to siezing handbrake if I understand correcly.. Will that be a problem om a purely sommer driven car?

Post

Back to the top
Seems like a comprehensive list.

I didn't use any proportioning valves for the rear, but I did upgrade the fronts at the same time. I don't know if this made any difference.

Later cabriolets had proportioning valves at the master cylinder. They can be used. They are quite expensive new however. They mount into the master cylinder.
They aren't adjustable as far as I'm aware but are there to stop the back locking up.

The mk4 calipers are aluminium instead of cast so they don't corrode. If you are completely stripping and re-building the calipers then they should be fine. However mk4 calipers are about £80 each new. Is it worth the hassle of buying and installing the re-build kits to then have them seize later? I've had mk2 that's seized, and used mk4's that seized. In the end I went with new as I was fed up with doing them.

Having a car only used in the summer is sometimes the issue as stuff is left for months to bind.

If you go with flexi lines to the calipers (which you don't need to do as solid lines can be used, then you will need to make a bracket attached to the beam to make the transition.

Routing of the handbrake cables is interesting. Don't cut the tubes mounted to the body and run the handbrake cables through the beam.

Ian

Cornish Host.
1980 VW Derby
Clive the Cabby
Ujum the Invisible
Mynx the  Tintop

Post

Back to the top
Thanks for your reply! I do not have any proportioning valves on my cabriolet since its a -87. I have to source new ones.

Wilwood simple models (one for each line):
Wilwood Disc Brakes - Porportioning Valves & Pressure Valves

I really dont need to adjust them myself if I can find other ones that I know will work. I have found Golf mk2, new for a reasonable price but have to find a "How To" to install them.

Post

Back to the top
I don't know why you couldn't use a set of proportional valves off a cabriolet…to use to regulate the force of pressure off of a rear disk set up.

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

Post

Back to the top

Rear brake drums to disc conversion

Are the cabriolet ones the best route to go then there is no question. I got the distinction that they are expensive to buy and I have not been able to find a part number for them yet.. i hade a browse through the parts catalog and could only find one that looked similar to the mk2. Not fitted om the master cylinder..

I have also upgraded front calipers (mk2 GTI) and master cylinder (22mm).

Last edit: by Vidde

Post

Back to the top
the ETKA don't show the correct ones for my cabbies.
and I am a tad under the weather to go take a look…

The pn is    533612151

 

Is where they are on my LHD Cabriolet….

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

Post

Back to the top

Vidde said

Thanks for your reply! I do not have any proportioning valves on my cabriolet since its a -87. I have to source new ones.

Wilwood simple models (one for each line):
Wilwood Disc Brakes - Porportioning Valves & Pressure Valves

I really dont need to adjust them myself if I can find other ones that I know will work. I have found Golf mk2, new for a reasonable price but have to find a "How To" to install them.
The Wilwood works well, have it on my mk1 rocco, Polo 6n servo moved over, 25mm master, wilwood calipers up front with 256 discs, polo gti rear hubs, calipers and discs back end, bias at around 50%, no load valve or reducers, brakes are awesome, no locking up

3B9D1A10-0F50-4AF9-84E7-392FA3740A3F.jpeg

Post

Back to the top
Thanks everyone for your reply! I have made a closer look at my car and I have no proprotioning valves fitted to my rear axel but have the ones that screws in to the MC. To avoid rear lock up, and peace of mind, I will get Tilton brake proportioning valves for my rear disc convertion, one for each side. 

Post

Back to the top

hubbadubba said

Vidde said

Thanks for your reply! I do not have any proportioning valves on my cabriolet since its a -87. I have to source new ones.

Wilwood simple models (one for each line):
Wilwood Disc Brakes - Porportioning Valves & Pressure Valves

I really dont need to adjust them myself if I can find other ones that I know will work. I have found Golf mk2, new for a reasonable price but have to find a "How To" to install them.
The Wilwood works well, have it on my mk1 rocco, Polo 6n servo moved over, 25mm master, wilwood calipers up front with 256 discs, polo gti rear hubs, calipers and discs back end, bias at around 50%, no load valve or reducers, brakes are awesome, no locking up

3B9D1A10-0F50-4AF9-84E7-392FA3740A3F.jpeg

Hi - I've been looking at the Wilwood Combination Proportioning valve - your set up looks great. Have you any more photos? Im installing a mk2 gti MC and 9" servo, just keen to see how I can make it all fit. Also, where did you get the fitting to split the rear brake lines?

Thanks
0 guests and 0 members have just viewed this: None.