Hydrovac unit and dual MC

[mcsmythe]

A little history,
I have an 80 with the 152, 3spd, twinstick, single mc with a mico brakelock and a bendix hydrovac unit attached to the vacuum off the intake manifold. When the previous owner installed the mico brake lock, he disconnected the hydrovac unit from the brakelines but it was still attached to the vacuum outlet on the manifold.

I am planning on replacing the single mc with a dual drum mc unit and was wondering if the hydrovac could be used with the dual setup to gain a little braking power. Going over the line routing in my mind, I am guessing the answer is "no" since there isn't a single source line but I thought I'd pose the question for anyone more knowledgeable on the subject.

 

[Greg R]

A hydrovac is for single circuit brakes. The master cylinder provides the initial pressure, and triggers the unit to boost it.

 

[ihpartsjeff]

a little history,
I have an 80 with the 152, 3spd, twinstick, single mc with a mico brakelock and a bendix hydrovac unit attached to the vacuum off the intake manifold. When the previous owner installed the mico brake lock, he disconnected the hydrovac unit from the brakelines but it was still attached to the vacuum outlet on the manifold.

I am planning on replacing the single mc with a dual drum mc unit and was wondering if the hydrovac could be used with the dual setup to gain a little braking power. Going over the line routing in my mind, I am guessing the answer is "no" since there isn't a single source line but I thought I'd pose the question for anyone more knowledgeable on the subject.

The answer is no it won't work as only one end of the vehicle will have power brakes since as you pointed out there is only one brake line going in and out of the hydrovac.