Can anybody tell me what I’m looking at? (Brakes)

[chucktaylor90]

I can’t tell what I’m looking at. It looks like there are 2 master cylinders? If you look at the picture 1 feeds into 2 which then goes out to the brakes. But then there are these hoses that connect to #2, the intake manifold, and the mystery cylinder #3?  I would imagine these probably were originally with this straight six. But I just can’t figure out how all this works.

[Rus Curtis]

I can’t tell what I’m looking at. It looks like there are 2 master cylinders? If you look at the picture 1 feeds into 2 which then goes out to the brakes. But then there are these hoses that connect to #2, the intake manifold, and the mystery cylinder #3?  I would imagine these probably were originally with this straight six. But I just can’t figure out how all this works.

I almost responded to your first post with your inline 6 image.  I was going to ask what that long canister was across the top (#3 in this image).  I quickly assumed you had booster brakes seeing the vacuum booster behind your m/c.  I'm not sure about the #2 and #3.  You may be right that it came with the engine transplant as upgrades. 

It's hard to see all the connections between the two images.  Can you show a more detailed image of how the plumbing looks between the containers?

[chucktaylor90]

More pics.

[chucktaylor90]

More pics

[SteveKfl]

Thanks for the better pics.  It is a Hydrovac brake booster.  The vacuum tubing has been bubba'd, and part of the confusion.  It also looks like there might be "swing down pedal controlling the brake master cylinder" and booster on the firewall.  If that is the case, the open T-fitting above it might suggest that booster isn't working, and they have the "remote booster" also.  The canister is most likely a "vacuum reservoir", but it should have 'two lines', one "in" and one "out" and a "check valve" to work.  Some use  the canister to also aid with the vacuum source supply to the wipers.
 
The correct plumbing would be the intake manifold to the vacuum port on the Hydrovac, and the brake line from the "brake MC source" to the Hydrovac, and then the brake line from under the "bleeder valve" visible to the brake line distribution block as the NEW PRESSURED SOURCE.  The brake pedal controls the original MC to pressure the Hydrovac MC to the brake lines.
 
Attached is one with poor pic locations on a Willys DJ.  Hope this helps, but maybe confuses more???