Brake mod idea. Any input welcome.

ping

I'm going to modify the brake circuit on my scooby powered split from cingle circuit to dual circuit before it goes back on the road.

My idea is (keeping well rebuilt drum brakes) to use the legacy servoM/C as it came from the legacy but without the proportioning valve that would normally go with the legacy brakes.

When people usually mod the split brakes to dual circuit with drums all round i dont think they proportion off the pressure at all.

Providing i can actually fit it to the van and the pedal, has anyone got any thoughts? I could do with a way of remote mounting the reservoir but i dont think this would be too hard in the scheme of things!

jp · Posted: Thu Jan 05, 2012 12:19 pm Post subject:

Could be worth asking one of the guys on this thread as they have played with their splitty brakes.
_________________
1971 Devon Bay with 1800 Ford Turbo Diesel Engine (wip)
1983 VW Golf GTI Campaign
1979 Mini 1275 GT
2013 Scirocco TDI GT

13 window deluxe · Posted: Sun Jan 08, 2012 8:21 pm Post subject:

what diameter is the scooby master cylinder? if its a similar diameter it should all be ok, you might have to add residual pressure valves in the mc outlets as drums have a tendency to shove fluid back into the master cylinder due the shoe return spring pressure meaning you have to pump up the brakes everytime
_________________
1964 rat 13 window deluxe 1Z tdi,
1975 rhd twin slider tintop (TBA)
1991 golf 2 gti with tweaked AHU tdi,

previous tdi swaps: gone but not forgotten
1979 rhd twin slider tintop bay ahu 1.9tdi
1990 T25 1Z 1.9tdi
1993 suzuki samurai with 1Z 1.9tdi

ping · Posted: Fri Feb 03, 2012 5:51 pm Post subject:

I'm not sure of the size of the legacy MC but i will have a look and compare it to the type 2 one which i think is 19mm. Are the residual pressure valves just non return valves as i'm struggling to find them for sale?
Another stupid question but if the subaru MC piston is larger than the type 2 one would that actually be better?

ping · Posted: Sat Feb 04, 2012 2:54 pm Post subject:

Found the valves now, willwood do em, 10 psi for use with drums and 2 psi for discs. Just got to find out the size of the mc pistons now.

13 window deluxe · Posted: Wed Feb 08, 2012 9:29 am Post subject:

ping · Posted: Fri Feb 10, 2012 7:45 pm Post subject:

Muchos gassyass.

ping · Posted: Sun Feb 12, 2012 6:04 pm Post subject:

Wilwood ten pound residual pressure valves retain a minimum brake line pressure to help eliminate excessive pedal travel in drum brake systems. With drum brakes, a ten pound valve is used to compensate for return spring tension and maintain wheel cylinder sealing in the drums. Residual Pressure Valves are made from billet aluminum and color coded for easy identification. Valves with fittings are supplied with two 1/8-27 NPT to 3/-24 inverted flare female fittings that will most domestic 3/16th hard brake line.

From the Wilwood website!

ping · Posted: Mon Feb 13, 2012 8:03 pm Post subject:

Ah pish. Just found time to grab the legacy mc, it's 1-1/16 (25.5mm) which means it's far too big, it wouldn't be worth doing as the pressure produced would be too low for discs. :0( suppose i'll follow the sheep now and do the normal splitty dual circuit conversion!