Hi all
Looking to buy a buggy which has a king and link pin chassis.
can anyone advise how easy/hard it is to do a disc coversion on an early chassis with a king and link pin front end? I see a conversion kit on Justkampers (link below). Is this a good way to go - or should i consider changing front end to ball and joint? And what are implications here (as i was advised that king and link pin limits disk brake conversion on the front as you have to add drop spindles which lower the front end)
Any idea of costs also assuming a pro did the work
Many thanks

https://www.justkampers.com/air-cooled-vw-parts/vw-beetle-parts/braking-system/brake-discs-backing-plates-fittings/22-2880-0-front-disc-brake-kit-5-x-205-vw-beetle-1956-1965.html

Why do you feel the need for discs on something so light? Even regular drum brakes will lock up easily on the front of a buggy.

You can do a disc conversion on a ball joint front end using standard Beetle, KG etc parts but this would involve changing the whole of the chassis' frame head as well as the axle, and leave you with 4 bolt hubs.

Quote from: Manxdavid on June 15, 2019, 01:54:11 PM
Why do you feel the need for discs on something so light?

If you are going down IVA route then discs are now mandatory   

Good practice to use latest requirements whatever the build 

Quote from: Dave DND on June 15, 2019, 03:02:24 PM

Quote from: Manxdavid on June 15, 2019, 01:54:11 PM
Why do you feel the need for discs on something so light?

If you are going down IVA route then discs are now mandatory   

Good practice to use latest requirements whatever the build 

I'd never attempt to try to get an existing buggy adapted to pass IVA, it'd need a complete strip down and rebuild, but there again I'd never buy a buggy that wasn't already correctly registered  unless it was just for parts.

I recon it'd be much easier to built a compliant buggy from scratch than to try to rework an oldie, IMHO of course!

Quote from: EOL1975 on June 15, 2019, 11:03:59 AM
Hi all
Looking to buy a buggy which has a king and link pin chassis.
can anyone advise how easy/hard it is to do a disc coversion on an early chassis with a king and link pin front end? I see a conversion kit on Justkampers (link below). Is this a good way to go - or should i consider changing front end to ball and joint? And what are implications here (as i was advised that king and link pin limits disk brake conversion on the front as you have to add drop spindles which lower the front end)
Any idea of costs also assuming a pro did the work
Many thanks

https://www.justkampers.com/air-cooled-vw-parts/vw-beetle-parts/braking-system/brake-discs-backing-plates-fittings/22-2880-0-front-disc-brake-kit-5-x-205-vw-beetle-1956-1965.html

Just by way of help. Will be converting my king & link pin buggy to disc this coming week.  Using CSP conversion kit. (Same method applies to Empi). I will post step by step procedure with photo`s.  There is one must do however and that is to use a specific twin circuit brake master cylinder. More later in the week.   

You should budjet for RPVs (residual pressure valves) for at least the front brake lines. They maintain a small amount of pressure in the lines (typically 2 or 10 psi) to stop the caliper pistons from creeping back hence increasing pedal travel. Rear brakes are usually (although not always) okay as the adjusters keep the linings close to the drums. VW fitted valves as standard in most m/cyls (single circuit!) when they brought in front discs in '67 but they don't tend to be fitted to aftermarket replacement m/cyls. This is an inexact science though and it's often a case of trial and error.

If you do find you do need RPVs just watch out for thread mismatches, VW brake lines are 10mm x 1mm pitch but a lot of US derived valves are often 1/8" npt, close but different.

Quote from: Manxdavid on June 16, 2019, 10:03:12 AM
You should budjet for RPVs (residual pressure valves) for at least the front brake lines. They maintain a small amount of pressure in the lines (typically 2 or 10 psi) to stop the caliper pistons from creeping back hence increasing pedal travel. Rear brakes are usually (although not always) okay as the adjusters keep the linings close to the drums. VW fitted valves as standard in most m/cyls (single circuit!) when they brought in front discs in '67 but they don't tend to be fitted to aftermarket replacement m/cyls. This is an inexact science though and it's often a case of trial and error.

If you do find you do need RPVs just watch out for thread mismatches, VW brake lines are 10mm x 1mm pitch but a lot of US derived valves are often 1/8" npt, close but different.

Thanks David... I would probably have forgotten to mention this. I know of a few people who have tried brake pipe into the rpv thinking it a poor item due to leakage.   There are adaptors to match one to the other. It is an inexact science and what works in one case may give a differing result in another. The standard for disc system appears to be accepted now at 2psi per valve each side. It would aslo appear that the preferred fitment is 1 per side at front just after the brake line and not immediately after the m cylinder ports.

When VW fitted them as stock, like on this 1303, they screwed straight into the cylinder body.

https://s147.photobucket.com/user/David58Bug/media/New%2520Stuff/stockresidualpressurevalves.jpg.html

Thanks all

Quote from: Manxdavid on June 16, 2019, 07:08:30 PM
When VW fitted them as stock, like on this 1303, they screwed straight into the cylinder body.

https://s147.photobucket.com/user/David58Bug/media/New%2520Stuff/stockresidualpressurevalves.jpg.html

The current aftermarket valves are about a inch and a half in length, (will upload a photo). I have seen quiet a few home builds now with them fitted and the majority have been positioned at the end of the metal line at the frame head brake line support piece immediately before the flexi hose. I don`t know if it makes any technical difference as to the actual location. Quite a few builders I have talked to frown on these valves and don`t fit them. I have yet to try mine to make any realistic judgement. 

RPV's seem to come up quite often, we have 2 buggies on front discs without them and they are fine, some info puts them as not to be used with disc brakes but then with properly adjusted drum brakes there is no need for them. A couple of psi in a line just stops the seals and run out from pushing the pads to far clear.

Always fit them as close to the master cylinder as possible, since part of their function is to reduce drainback.

Got discs all round and correct master cylinder. Bought a pair of 2 psi valves cos I thought I had too much stroke on the brake pedal. Never fitted them. My MOT man always comments how good my brake efficiency is 🤷🏻‍♂️

Brake efficiency is just a function of the stopping power compared to the weight of the car, nothing to do with knockback and pedal travel which is what the valves are for.