Fluid routing from master cylinder ('69 CJ-5)

I'm overhauling my brakes...here's the issue. I keep losing fluid, but I can't find where. After noticing a dry master cylinder (with a bit of debris), I recently flushed a quart of fluid through the lines, bled out all the air, and everything was working great. A few days later, I left the house and had about 20% breaking power, only to discover that the front side of the reservoir was bone dry (the back was still approx. 2/3 full).

So....I did another investigation and still found no evidence whatsoever of any fluid leakage anywhere...the cylinder is pretty old (I'm pretty sure it's from a similar year Jeepster or Wagoneer, judging from pictures: http://www.cardone.com/Products/Product-Detail?productId=101292&p=rock ), but everything appears to be dry along the line routing, at the wheel cylinders, etc. The front right brake drum, however, is pretty badly warped and impossible to remove without drastic measures (destroying it in the process).

As a result, I said screw it, let's just go ahead and put discs on. I wanted to eventually anyway. I found R&P's kit for $525 + $75 shipping, which seems better than shopping for a dana 30 on ebay and then replacing all the rusted components anyway. I'm also putting in a new MC, same as the one in now.

MY QUESTION (unless you have some suggestions for locating this leak): the salesman said he'd do me a solid and go ahead and take out the 10 lb. RPV in the MC...albeit the REAR cylinder (the one that still had fluid), since apparently the rear cylinder goes to the front brakes, and the front to the rear brakes (b/c that makes sense). I'm not sure how mine goes at the moment since I'm at work, but is this typical? Not a big deal since I'll just have to move the leftover RPV in the MC to the other side if so, but I do need to know which line to put the new 2 lb. RPV in. My MC sends two lines to a small metering block (?), and then two lines come out and split off to the front and rear (**but how the fluid is routed in that block, I'm not sure).

I just hope I'm not overhauling the front if the rear brakes are the issue...b/c I'll just end up having to overhaul them as well.

Thanks for the help as always!

 

Colonel,
The link to the pics at Cardone are not the original MC.
If you have the original MC, it should have casting marks on it indicating Wagner Lockheed, and it will have a cover retained by a center bolt.
If you have this MC, it will be a step bore design, with the smaller bore on the front piston, fed by the front reservoir. This will connect to the lines to the front brakes.
This design needs no proportioning valve to achieve a differential pressure to front/rear brakes thus minimizing a tendancy for rear brake lockup.

The block that the two sets of lines from the MC run to is not a metering block, just a dual junction block machined in a single piece of brass.

Don

 

The salesman said I would not need a proportioning valve unless I'm doing a lot of steep offloading. I meant to refer to the residual check valves--not a proportioning valve--that hold fluid pressure on the brakes.

I realize it's not original; I suspect one of the POs installed the one in the pic at some point, maybe just to upgrade to a dual reservoir (perhaps mine was one of the unlucky recipients of a single reservoir).