Rear Brake Proportioning Valve

[fastzrex]

I am beginning to plumb my brake system in my Super, and since it now has disc brakes all around, and I will replace all the hoses and hard lines, can anyone recommend a proportioning valve to use for the rear brakes? I am concerned about being able to attach the valve to new VW hard brake lines. Any ideas will be helpful?

[Bug@5speed(US)]

Wilwood makes some nice quality proportional valves, could try them?
Alex

[GS guy]

You'll have to do some adapting - the Wilwood (and other aftermarket) valves are 1/8NPT fitting, while the VW lines use metric bubble flare. Depending on where you want to mount the valve you may have to install some new metric hard lines - or else try and splice it into an existing line?
CNC and others make the metric to NPT adapter fittings.
http://cncbrakes.com/

Jeff

[fastzrex]

Wilwood makes some nice quality proportional valves, could try them?
Alex
Thanks for the recommendation. I'll check them out!

[fastzrex]

You'll have to do some adapting - the Wilwood (and other aftermarket) valves are 1/8NPT fitting, while the VW lines use metric bubble flare. Depending on where you want to mount the valve you may have to install some new metric hard lines - or else try and splice it into an existing line?
CNC and others make the metric to NPT adapter fittings.
http://cncbrakes.com/

Jeff
Thanks for the link. I have looked for such adapters, and now I know where to find them. This allows much flexibility in how to install the system. I believe I will run an US brake line front to rear and mount the valve under the rear seat.

I wonder if the proportioning valve should be higher than the master cylinder, and then install a bleeder by the valve? Any thoughts?

Thanks again for your help!

[GS guy]

I'd mount the prop valve as low as possible, then plumb a new short line to the rear T fitting. Then run a new slightly shorter (than stock) line to the front. If you're running a VW pedal assembly and mastercylinder, I'd try to stick with all VW stuff/metric fittings as much as possible. The more connections/adapters, the more chances of a leak!
I've seen generic bubble flare lines of many various lengths (but can't remember where at the moment?), so you could just make up your own system.

I'd also plan on one of these - pressure bleeder:
http://www.motiveproducts.com/02bleeders.html

Too much fight'n and cuss'n to bleed a new (dry) system and get all the air out! BTDT! :mad:
Jeff

[volkdent]

Speaking from recent experience, if you just cut the stock VW line, you can re-flare it for the double-flare 1/8th". I can't guarantee this, but I think if you get a Wilwood brake proportioning valve and a couple of nipples, you can just cut out the stock line where you want the valve, double-flare the ends, and bolt that up to the valve. Then you'll have hybrid lines, half bubble metric, half 1/8th NPT. I used the stock VW lines to tie into the steel braided cables that are meant for VW Jetta, and the other end I did to attach to a standard T. The only think that might be a problem for you is that I would want my valve within arms reach, and unless you can pull any excess, the valve would then be low where the stock line runs.

Jason

[Wally]

Speaking from recent experience, if you just cut the stock VW line, you can re-flare it ...
Jason
That is what I am going to do. I just bought a tool (10mmx1.0)for this :D

Summit has real nice Tilton brake bias proportioning valves in stock metric 10mmx1.0 size). I got one of these:

http://www.keversite.nl/fotoalbum/fotos/61124.jpg

[volkdent]

That looks great Wally, and easy to adjust on the fly. I always wonder how those longer levers work in daily drivers, if they get caught on stuff or not, but there's no denying the ease under way!

Jason

[Wally]

Good point about the lever, but I think they also have one with a knob if that concerns you.
This one is NOT going into my daily driver ;)

[volkdent]

Good point about the lever, but I think they also have one with a knob if that concerns you.
This one is NOT going into my daily driver ;)

Mine will be a fun weekend thing, but I got the knob myself!

[Wally]

I installed it. Best place was this as I can reach it from the drivers side and it doesn't touch my leg. It not in the way for a passenger either now :)

http://www.keversite.nl/fotoalbum/fotos/62953.jpg