Cutting brakes residual valve

[Rusti shakelfurd]

OK so I know there are some similar discussions close to my question but I Couldnt find one exactly what my problem is.. so on my rail I have just rear drum brakes all new all the way around don't remember the size of the master cylinder but it's a Varga Brazilian one and Jamar dual handle cutting brakes the brakes work OK the pedal is stiff but it stI'll locks up the tires if you stand on it but the turning brakes are spongy as crap unless I push on the brake pedal and pull up on the handle then they are stiff and work awesome so any thoughts on do I need a residual valve or two of them after the cutters before the wheel cylinders any advice is appreciated
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1961 baja (soon to be turbo 1600)
Home made sand and woods rail

[Aerindel]

I have the same exact problem and a similar set up. 3/4 Latest Rage MC and CNC cutting brakes. Rear only drums.

I think what is happening is that when you first pull on the cutting brakes the hydraulic circuit is open and they are pushing fluid back into the MC. Once the pistons move far enough they close off the MC line and isolate that side of the brake system and start applying pressure to the brakes but only in the last bit of their travel. It works okay but feels terrible. If you step on the main brake the MC piston moves far enough forward to close the line which is why the cutting brakes feel solid if the main brake pedal is slightly depressed first and why the foot brake feels resistance immediately and the cutting brakes do not.

I have a 10 PSI pressure valve that came with my buggy that I have yet to install. I think the correct place to put it is right after the MC so that the entire brake system is under pressure, including your cutting brakes. The will still backfeed into the MC until the piston is closed off but they will be pushing against a 10# valve so they won't be completely spongy and some of that force will start working against the brakes immediately.

That is theory #1

Theory #2 is to adjust the push rods on the cutting brake so that they are very close to the position where you start to feel resistance in the fully open position. My worry is that this could cut off the MC from the rest of the brake system and leave you with only cutting brakes. In order to work properly the cutting brake pistons have to leave the brake circuit open until you actually use them.

either way, I want to figure out something because its just ridiculous how they are now, I get no resistance at all for 80% of their stroke and then all the braking force has to be applied in the last inch of travel. They don't even fully return to the off position on their own until I step on the main brake.
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Homemade woods/street, bug out rail. IRS, Balljoint front end. 1967 1600cc DP, Weber 32/36 progressive, tri-mil quiet pack. Rear only cutting brakes.

http://www.thesamba.com/vw/forum/viewtopic.php?t=630046

[Rusti shakelfurd]

Ya that makes perfect sense thanks allot man I would agree we have the same exact symptoms now just a thought I was having I don't know what kind of reservoir you have but I have some stupid Lil chrome one (I will put a picture) if you filled it to the brim would there be no room for fluid to back feed into the reservoir then just put the pressure on the cap ??? I think I will try Just because I think I will also order a pressure valve to try and yes I agree very ridiculous I just got back from the dunes and it was a pita to remember to pump up the brakes every time I went for the turning brake it would be nice if they were just pumped up every time I needed them

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1961 baja (soon to be turbo 1600)
Home made sand and woods rail