Not 100% sure what you mean by "two res." When I said three chambers, I was not refering to the
reservoir or
residual valves.
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The items called out in fig.5 are added to a master used with low drag calipers. The shape of the caliper piston seal pulls the piston back away from the rotor. The low pressure chamber returns the fluid to the caliper in the first of a series of three steps before your foot can apply full pressure to both front and rear(reduced for disc/drum).
Everything I've read says that the low drag caliper will not work without this master. Using it the other way around?? I have not been able to find anything about using this master with standard calipers or even drums/front. I think, if the piston is already "out", the low pressure chamber should just vent its fluid out through the take-up valve to the reservoir.
Rebuild kits do not include a take-up valve and they are nearly impossible to remove without damage. I have to wonder if rebuilders replace or even test the valve.
I have to agree that for this master on drum/drum, you wouldn't want the combination valve and should use two 10LB residual valves.
